WO2023116834A1 - Nonlinear correction method, apparatus and system - Google Patents

Nonlinear correction method, apparatus and system Download PDF

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Publication number
WO2023116834A1
WO2023116834A1 PCT/CN2022/141085 CN2022141085W WO2023116834A1 WO 2023116834 A1 WO2023116834 A1 WO 2023116834A1 CN 2022141085 W CN2022141085 W CN 2022141085W WO 2023116834 A1 WO2023116834 A1 WO 2023116834A1
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Prior art keywords
signal
product
parameters
int
orthogonal
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PCT/CN2022/141085
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French (fr)
Chinese (zh)
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李弘旻
刘发林
刘乔
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华为技术有限公司
中国科学技术大学
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Publication of WO2023116834A1 publication Critical patent/WO2023116834A1/en

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/38—Synchronous or start-stop systems, e.g. for Baudot code
    • H04L25/40—Transmitting circuits; Receiving circuits
    • H04L25/49—Transmitting circuits; Receiving circuits using code conversion at the transmitter; using predistortion; using insertion of idle bits for obtaining a desired frequency spectrum; using three or more amplitude levels ; Baseband coding techniques specific to data transmission systems
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
    • H03F1/32—Modifications of amplifiers to reduce non-linear distortion
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
    • H03F1/32—Modifications of amplifiers to reduce non-linear distortion
    • H03F1/3241—Modifications of amplifiers to reduce non-linear distortion using predistortion circuits
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2614—Peak power aspects

Definitions

  • the embodiments of the present application relate to the technical field of signal processing, and in particular to a nonlinear correction method, device and system.
  • the communication system provides increasingly higher signal bandwidth and more and more complex modulation methods.
  • this will cause the communication signal to have a high peak-to-average power ratio (PAPR), referred to as peak-to-average ratio.
  • PAPR peak-to-average power ratio
  • orthogonal frequency division multiplexing orthogonal frequency division multiplexing (orthogonal frequency division multiplexing, OFDM) communication technology shown in Figure 1 as an example, since the OFDM symbol is composed of multiple independently modulated subcarrier signals (as shown in Figure 1 ) are superimposed, when the phases of each subcarrier are the same or close, the superimposed signal will be modulated by the same initial phase signal, resulting in a larger instantaneous power peak, which further leads to a higher PAPR.
  • OFDM orthogonal frequency division multiplexing
  • a power amplifier (power amplifier, PA) is an important component of a transmitter, and it naturally has nonlinear characteristics.
  • PA power amplifier
  • the input signal with higher PAPR is more sensitive to the nonlinearity of the PA, which can easily aggravate the nonlinear distortion of the signal.
  • the nonlinear distortion of the signal will not only spread the spectrum to cause adjacent channel interference, but also deteriorate the error vector magnitude (EVM) of the transmitted signal, increase the bit error rate of the receiver, and cause the operating point of the PA to roll back Thereby reducing the efficiency of the transmitter. Therefore, high PAPR has become a major technical obstacle for high-capacity, high-speed communication systems.
  • EVM error vector magnitude
  • the present application provides a nonlinear correction method, device and system, which can improve the nonlinear correction performance of a predistortion device.
  • a non-linear correction method includes: performing preset processing on the first signal to obtain the second signal; generating an orthogonal regression matrix based on the first signal; and constructing the obtained orthogonal regression matrix according to the orthogonal regression matrix Power amplifier (PA) forward modeling formula; Generate orthogonal basis function according to this PA forward modeling formula; By integrating the product of this orthogonal basis function and above-mentioned second signal, obtain PA model parameter; According to this PA Model Parameters adjusts the nonlinearity correction parameters.
  • PA Power amplifier
  • the parameters of the power amplifier model are realized.
  • the extraction realizes the prediction of the output of the power amplifier under the condition of full sampling, and then according to the actual demand, the nonlinear correction parameters, such as the pre-distortion parameters, are trained to improve the nonlinear correction performance of the digital pre-distortion device and solve the nonlinear distortion problem of the transmitter .
  • the above-mentioned nonlinear correction parameter is a digital pre-distortion (digital pre-distortion, DPD) parameter.
  • DPD digital pre-distortion
  • the nonlinear correction method provided in the present application may be implemented based on a DPD device, wherein the core of the nonlinear correction lies in performing DPD parameter training and adjustment.
  • the PA model parameters are obtained by integrating the product of the orthogonal basis function and the second signal, including: integrating the orthogonal basis function and the I-channel signal and the Q-channel signal of the second signal, respectively Multiply to obtain the I-way product and the Q-way product; integrate the I-way product and the Q-way product according to a preset period to obtain PA model parameters.
  • the above preset period is T int , and T int satisfies: T int ⁇ N int Ts; wherein, N int is a preset value, and N int is related to the number of PA model parameters and/or emission It is related to the performance of the machine, and Ts is the sampling period in the case of full sampling.
  • the above-mentioned integration of the I-way product and the Q-way product according to the preset period to obtain the PA model parameters includes: integrating the I-way product and the Q-way product at the first moment to obtain the first A PA model parameter, where the first condition is met at the first moment; and the I-way product and the Q-way product are integrated at the second moment to obtain a second PA model parameter, where the second condition is met at the second moment.
  • the first moment satisfies (2k-2)T int ⁇ t ⁇ (2k-1)T int
  • the first PA model parameter is the real part of the PA model parameter
  • the second moment satisfies (2k-1)T int ⁇ t ⁇ 2kT int
  • the second PA model parameter is the real part of the PA model parameter.
  • the above-mentioned first signal is a signal of a preset frequency band in the input signal.
  • the method provided in this application supports the extraction of PA model parameters by frequency bands, so as to reduce the training time of DPD parameters.
  • the above method further includes: performing nonlinear correction parameter adjustment on signals of all frequency bands in the input signal using the same method as that of the first signal.
  • the method provided in this application supports the extraction of PA model parameters by frequency bands, so as to reduce the training time of DPD parameters.
  • the above method further includes: when the nonlinear correction parameter is stable, performing signal nonlinear correction before signal transmission according to the adjusted nonlinear correction parameter.
  • the sampling rate and sampling time can be considered comprehensively when performing nonlinear correction.
  • this method can also reduce the ADC cost when nonlinear correction.
  • the above-mentioned multiplication of the orthogonal basis function with the I-channel signal and the Q-channel signal of the second signal to obtain the I-channel product and the Q-channel product includes: synchronously multiplying the orthogonal basis function with the first The I-channel signal and the Q-channel signal of the two signals are respectively multiplied to obtain the I-channel product and the Q-channel product.
  • the synchronous processing of the I-channel signal and the Q-channel signal may be implemented through a delayer.
  • the generating the orthogonal regression matrix based on the first signal includes: generating the regression matrix based on the first signal; performing orthogonal transformation on the regression matrix to obtain the orthogonal regression matrix.
  • the preset processing of the first signal to obtain the second signal includes: performing digital pre-distortion, digital-to-analog conversion, quadrature modulation, and power amplification on the first signal to obtain the second signal. Signal.
  • a nonlinear correction device which includes: a transmitting module, configured to perform preset processing on the first signal to obtain a second signal; a basis function generation module, configured to: based on the above-mentioned first
  • the signal generates an orthogonal regression matrix; according to the orthogonal regression matrix, a power amplifier (PA) forward modeling formula is constructed; and, according to the PA forward modeling formula, an orthogonal basis function is generated; the integral analog-to-digital conversion module is used
  • PA model parameters are obtained by integrating the product of the orthogonal basis function and the above-mentioned second signal; the pre-distortion module is used for adjusting the nonlinear correction parameter according to the PA model parameters.
  • the transmitting module may include a digital-to-analog converter (digital-to-analog converter, DAC) and a PA.
  • DAC digital-to-analog converter
  • the integral analog-to-digital conversion module is such as an integral DAC.
  • the parameters of the power amplifier model are realized.
  • the extraction realizes the prediction of the output of the power amplifier under the condition of full sampling, and then according to the actual demand, the nonlinear correction parameters, such as the pre-distortion parameters, are trained to improve the nonlinear correction performance of the digital pre-distortion device and solve the nonlinear distortion problem of the transmitter .
  • the above-mentioned nonlinear correction parameters are DPD parameters.
  • the nonlinear correction method provided in this application can be implemented based on a DPD device, wherein the core of the nonlinear correction lies in the training and adjustment of DPD parameters.
  • the above integral analog-to-digital conversion module is specifically configured to: multiply the orthogonal basis function with the I-channel signal and the Q-channel signal of the second signal to obtain the I-channel product and the Q-channel product; according to The I-way product and the Q-way product are integrated at a preset period to obtain PA model parameters.
  • the extraction of various parameters of the PA model can be realized, so as to estimate the output of the power amplifier in the case of full sampling, and then train the DPD parameters according to the estimated output of the power amplifier in the case of full sampling.
  • the above preset period is T int , and T int satisfies: T int ⁇ N int Ts; wherein, N int is a preset value, and N int is related to the number of PA model parameters and/or emission It is related to the performance of the machine, and Ts is the sampling period in the case of full sampling.
  • the above integral analog-to-digital conversion module is specifically configured to: integrate the I-way product and the Q-way product at the first moment to obtain the first PA model parameter, wherein the first condition is met at the first moment; Integrate the I-way product and the Q-way product at a second moment to obtain a second PA model parameter, wherein the second condition is satisfied at the second moment.
  • the first moment satisfies (2k-2)T int ⁇ t ⁇ (2k-1)T int
  • the first PA model parameter is the real part of the PA model parameter
  • the second moment satisfies (2k-1)T int ⁇ t ⁇ 2kT int
  • the second PA model parameter is the real part of the PA model parameter.
  • the extraction of each parameter of the PA model can be realized by means of time division.
  • the above-mentioned first signal is a signal of a preset frequency band in the input signal.
  • the method provided in this application supports the extraction of PA model parameters by frequency bands, so as to reduce the training time of DPD parameters.
  • the above-mentioned pre-distortion module is further configured to: perform non-linear correction parameter adjustment on signals of all frequency bands in the input signal using the same method as that of the first signal.
  • the method provided in this application supports the extraction of PA model parameters by frequency bands, so as to reduce the training time of DPD parameters.
  • the above-mentioned pre-distortion module is further configured to perform signal nonlinear correction before signal transmission according to the adjusted nonlinear correction parameter when the nonlinear correction parameter is stable.
  • the sampling rate and sampling time can be considered comprehensively when performing nonlinear correction.
  • this method can also reduce the ADC cost when nonlinear correction.
  • the above integral analog-to-digital conversion module is specifically configured to: synchronously multiply the orthogonal basis function with the I-channel signal and the Q-channel signal of the second signal to obtain the I-channel product and the Q-channel product.
  • the synchronous processing of the I-channel signal and the Q-channel signal may be implemented through a delayer.
  • the above-mentioned basis function generation module is specifically configured to: generate a regression matrix based on the first signal; and perform an orthogonal transformation on the regression matrix to obtain an orthogonal regression matrix.
  • the transmitting module is specifically configured to: perform digital predistortion, digital-to-analog conversion, quadrature modulation, and power amplification on the first signal to obtain the second signal.
  • a computer-readable storage medium where computer program code is stored on the computer-readable storage medium, and when the computer program code is executed by a processor, the method in any possible implementation manner of the first aspect is implemented .
  • a chip system in a fourth aspect, includes a processor, a memory, and a computer program code is stored in the memory; when the computer program code is executed by the processor, any possible method in the implementation.
  • the system-on-a-chip may consist of chips, or may include chips and other discrete devices.
  • a computer program product which, when running on a computer, enables the method in any possible implementation manner of the first aspect to be implemented.
  • FIG. 1 is a schematic diagram of an OFDM communication technology communication process provided by an embodiment of the present application
  • FIG. 2 is a time-domain waveform diagram of an OFDM signal provided by an embodiment of the present application.
  • FIG. 3 is a schematic diagram of nonlinear characteristics of a power amplifier (PA) provided in an embodiment of the present application;
  • PA power amplifier
  • FIG. 4 is a first schematic diagram of the working process of the transmitter provided by the embodiment of the present application.
  • FIG. 5 is a second schematic diagram of the working process of the transmitter provided by the embodiment of the present application.
  • FIG. 6 is a third schematic diagram of the working process of the transmitter provided by the embodiment of the present application.
  • FIG. 7 is an example diagram of a communication scenario provided by an embodiment of the present application.
  • FIG. 8 is a schematic diagram of a hardware structure of a sending end/receiving end provided by an embodiment of the present application.
  • FIG. 9 is a schematic diagram 4 of the working process of the transmitter provided by the embodiment of the present application.
  • FIG. 10 is a schematic diagram of a parameter sampling process of a power amplifier model provided by an embodiment of the present application.
  • FIG. 11 is an example diagram of performance parameters corresponding to different multiples of undersampling provided in the embodiment of the present application.
  • FIG. 12 is a schematic diagram 5 of the working process of the transmitter provided by the embodiment of the present application.
  • FIG. 13 is an example diagram of a bandwidth of a band-limit filter provided in an embodiment of the present application.
  • FIG. 14 is a schematic diagram of another power amplifier model parameter sampling process provided by the embodiment of the present application.
  • FIG. 15 is a sixth schematic diagram of the working process of the transmitter provided by the embodiment of the present application.
  • FIG. 16 is a seventh schematic diagram of the working process of the transmitter provided by the embodiment of the present application.
  • first and second are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, a feature defined as “first” and “second” may explicitly or implicitly include one or more of these features. In the description of this embodiment, unless otherwise specified, “plurality” means two or more.
  • Orthogonal Frequency Division Multiplexing OFDM
  • the main idea of OFDM is that the sending end divides the channel into several orthogonal sub-channels, and converts high-speed data signals into multiple parallel low-speed sub-data streams (as shown in Figure 1 ), transmitted through multiple sub-channels.
  • the receiving end may use related technologies to analyze and obtain multiple low-speed sub-data streams, so as to reduce mutual interference between sub-channels. Since the signal bandwidth on each sub-channel is smaller than the correlation bandwidth of the channel, each sub-channel can be regarded as flat fading, so that the intersymbol interference can be eliminated. Moreover, since the bandwidth of each sub-channel is only a small part of the original channel bandwidth, channel equalization becomes relatively easy.
  • PAPR Peak-to-average ratio
  • PAPR is a measurement parameter for a signal.
  • PAPR is a measurement of the dynamic range of the input amplitude of a wireless transmitter, and PAPR can be used as one of the indicators used to measure the performance of the transmitter.
  • PAPR is used to characterize the ratio of the amplitude of the signal to the effective value (such as root mean square (RMS)).
  • RMS root mean square
  • PAPR is defined as follows:
  • x(t) represents the OFDM signal
  • T represents the accumulation time period.
  • FIG. 2 shows a schematic diagram of an OFDM signal.
  • the OFDM peak shown in FIG. 1 is max 0 ⁇ t ⁇ T x(t)
  • the OFDM mean is mean 0 ⁇ t ⁇ T x(t).
  • the output signal is nonlinearly deformed relative to the input signal, thereby bringing unhelpful interference signals and affecting the correct transmission and reception of information. This phenomenon is called nonlinear distortion.
  • the power amplifier has a characteristic of nonlinear distortion, that is, the PA has nonlinear characteristics.
  • the PA has a characteristic of nonlinear distortion, that is, the PA has nonlinear characteristics.
  • the input signal has a linear relationship with the input signal.
  • the output power P out1 has a linear relationship with the input power P in1 .
  • the output power gradually becomes non-linear.
  • the output power P out2 has a nonlinear relationship with the input power P' in2 , which deviates from the ideal value P in2 .
  • the transmitter Since the power amplifier (PA) is an important component of the transmitter, the transmitter has nonlinear characteristics. In order to correct the nonlinearity of the transmitter to improve the efficiency and communication quality of the transmitter. As an implementation manner, the nonlinearity of the transmitter can be corrected by introducing a digital pre-distortion (digital pre-distortion, DPD) technology.
  • DPD digital pre-distortion
  • the principle of DPD is: by providing a nonlinear characteristic that is equivalent to the distortion characteristic of the power amplifier (PA), but the function is opposite, the predistortion element can correct the nonlinearity of the power amplifier (PA), so that the synthesis of the input signal The processing result satisfies a linear relationship with the input signal.
  • the non-linearity of the transmitter can be corrected by cascading a predistorter element (Predistorter) and a power amplifier (PA).
  • the predistorter can provide nonlinear characteristics equivalent to the distortion characteristics of the power amplifier (PA), but the function is opposite, so that the predistorter can correct the nonlinearity of the power amplifier (PA).
  • FIG. 4 shows a schematic diagram of a working process of a transmitter provided in an embodiment of the present application. Wherein, x(t) shown in FIG.
  • y(t) is the output signal after the pre-distortion signal is amplified.
  • the output signal y(t) and the input signal x(t) satisfy a linear relationship.
  • a power amplifier can be cascaded with a band-limit filter integrated with a nonlinear correction function (such as a low-pass filter) to correct nonlinearities within a certain bandwidth.
  • a nonlinear correction function such as a low-pass filter
  • FIG. 5 shows a schematic diagram of a working process of another transmitter provided by an embodiment of the present application.
  • x(n) shown in FIG. 5 is an input signal
  • y(n) is an output signal after power amplification
  • y BL (n) is an output signal after band-limit filtering DPD.
  • the nonlinearity of the signal within the bandwidth of the band-limit filter can be corrected.
  • undersampling predistortion may be based on random demodulation.
  • a pseudo-random signal whose period is a sampling interval and whose value is 0 or 1 can be generated.
  • digital-to-analog converter DAC
  • PA digital-to-analog conversion and power amplifier
  • the random signal is randomly sampled to obtain a random sampling signal y R (t)
  • an output signal y ' (t) is obtained through a band-limited filter and analog-to-digital conversion.
  • the predistortion related parameters can be further adjusted according to the predistorted signal and the output signal y ' (t), so as to further improve the nonlinear correction performance of the DPD.
  • an embodiment of the present application provides a nonlinear correction method, which can make the power amplifier ( In the forward modeling process of PA), each parameter of the power amplifier model can be extracted independently, so as to realize the adaptive setting and adjustment of the parameters of the power amplifier model.
  • the non-linear correction method provided by the embodiment of the present application can also time-divisionally extract various parameters of the power amplifier model by introducing a multiplier and an integrator, so as to support the setting and adjustment of infinite multiples of undersampling.
  • a communication system for signal transmission may include a sending end, a receiving end, and a communication channel.
  • the communication channel such as a wireless channel or a wired channel
  • the wireless channel is such as air, vacuum, water and other media used for wireless transmission.
  • Wired channels such as fiber optics, copper wires, and other media used to transmit signals.
  • the sending end and the receiving end may be network devices or terminal devices.
  • the sending end is a network device
  • the receiving end is a terminal device.
  • the sending end is a terminal device
  • the receiving end is a network device.
  • both the sending end and the receiving end are network devices.
  • both the sending end and the receiving end are terminal devices. This application does not limit the specific functions and structures of the sending end and the receiving end.
  • the network device is an access network (access network, AN) or a radio access network (radio access network, RAN).
  • the AN/RAN may be various forms of base stations, such as macro base stations, micro base stations (also called “small cells"), distributed unit-control units (distribute unit-control unit, DU-CU), etc.
  • the above-mentioned base station may also be a wireless controller in a cloud radio access network (CRAN) scenario, or a relay station, an access point, a vehicle-mounted device, a wearable device, or a future evolved public land mobile network (public land mobile network, PLMN) network equipment, etc.
  • CRAN cloud radio access network
  • AN/RAN can also be a broadband network gateway (broadband network gateway, BNG), aggregation switch, non-3GPP access device, etc.
  • BNG broadband network gateway
  • the embodiment of the present application does not limit the specific form and structure of the AN/RAN.
  • the base station can be an evolved universal terrestrial radio access network (evolved universal terrestrial radio access network, E-UTRAN) device in LTE, such as an evolved node B (evolutional NodeB, eNB or e-NodeB), or it can be a 5G Next generation radio access network (NG-RAN) equipment (such as gNB) in the system.
  • E-UTRAN evolved universal terrestrial radio access network
  • NG-RAN Next generation radio access network
  • the terminal device is a desktop device, a laptop device, a handheld device, a wearable device, a smart home device, a computing device, a vehicle-mounted device, etc. with a communication function.
  • a communication function For example, netbooks, tablets, smart watches, personal computers (PCs), ultra-mobile personal computers (UMPCs), smart cameras, netbooks, personal digital assistants (PDAs), cellular Telephone, cordless phone, session initiation protocol (SIP) phone, wireless local loop (WLL) station, portable multimedia player (PMP), (augmented reality, AR)/virtual Reality (virtual reality, VR) devices, wireless devices on aircraft, wireless devices on robots, wireless devices in industrial control, wireless devices in telemedicine, wireless devices in smart grids, and wireless devices in smart cities (Smart City) Wireless devices, wireless devices in smart homes, etc.
  • the embodiment of the present application does not limit the specific type and structure of the terminal device.
  • terminal equipment In this embodiment of the application, terms such as “terminal equipment”, “mobile station (mobile station, MS)", “user terminal (user terminal)”, “user equipment (user equipment, UE)” and “terminal” may be used Used interchangeably.
  • Terminal equipment is also sometimes referred to by those skilled in the art as subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other appropriate term.
  • the base station in the embodiment of the present application may also be replaced by a user terminal.
  • various modes/embodiments of the present disclosure may also be applied to a configuration in which communication between a base station and a terminal device is replaced with communication between multiple user terminals (device-to-device, D2D).
  • the functions of the base station can be regarded as the functions of the user terminal.
  • words like "up” and “down” can be replaced with "side”.
  • uplink channels can also be replaced by side channels.
  • the user terminal in the embodiment of the present application can also be replaced by a base station. At this time, the above-mentioned functions of the user terminal may be regarded as functions of the base station.
  • the sending end includes a transmitter
  • the receiving end includes a receiver.
  • the transmitter in the sending end is used to support the sending end to transmit signals
  • the receiver in the receiving end is used to support the receiving end to receive signals.
  • the sending end may further include a receiver, and the receiving end may further include a transmitter.
  • the receiver in the sending end is used to support the sending end to receive signals
  • the transmitter in the receiving end is used to support the receiving end to transmit signals.
  • FIG. 7 shows a schematic diagram of a communication scenario provided by an embodiment of the present application.
  • the communication system in the communication scenario shown in FIG. 7 includes a transmitter at the sending end, a receiver at the receiving end, and a communication channel (the sending end and the receiving end are not shown in FIG. 7 ).
  • the transmitter includes a baseband processing unit 710, a DPD 720, a DAC 730, a transmitting radio frequency 740, and a PA750.
  • the receiver includes a receiving radio frequency 760 , an analog-to-digital converter (analog-to-digital converter, ADC) 770 and a baseband processing unit 780 .
  • ADC analog-to-digital converter
  • the baseband processing unit 710 in the transmitter is mainly used for information modulation, framing, filtering and shaping, pre-distortion correction, and the like.
  • DPD 720 is mainly used for nonlinear pre-correction of PA 750.
  • DAC 730 is mainly used for digital-to-analog conversion.
  • the radio frequency 740 is mainly used for modulating the baseband signal into a radio frequency signal, and filtering the signal.
  • PA 750 is mainly used for power amplification of signals.
  • the receiving radio frequency 760 in the receiver is mainly used for down-converting the received radio frequency signal to low frequency or baseband.
  • ADC770 is mainly used for analog-to-digital conversion.
  • the baseband processing unit 780 is mainly used to restore the baseband signal, such as synchronization and equalization.
  • the transmitter shown in FIG. 7 may further include an encoding unit, and the receiver may further include a decoding unit.
  • the coding unit is mainly used for error correction, coding, interleaving, etc. of information on the signal.
  • the decoding unit is mainly used for deciphering and decoding signals.
  • FIG. 7 is only an example of a communication architecture, and the present application does not limit the specific communication architecture of the communication system.
  • the communication system may further include other units or modules.
  • the transmitter or the receiver may include more communication devices than those shown in FIG. 7 or may not include a certain communication device shown in FIG. 7 .
  • FIG. 8 takes a terminal device as an example and shows a schematic diagram of a hardware structure of a sending end/receiving end.
  • the structure of the sending end/receiving end can be as shown in Figure 8, and the sending end/receiving end can include: a processor 810, an external memory interface 820, an internal memory 821, a universal serial bus (universal serial bus, USB) interface 830, charging management module 840, power management module 841, battery 842, antenna 1, antenna 2, mobile communication module 850, wireless communication module 860, audio module 870, speaker 870A, receiver 870B, microphone 870C, earphone jack 870D, sensor module 880, button 890, motor 891, indicator 892, camera 893, display screen 894, subscriber identification module (subscriber identification module, SIM) card interface 895, etc.
  • SIM subscriber identification module
  • the sensor module 880 may include a pressure sensor, a gyroscope sensor, an air pressure sensor, a magnetic sensor, an acceleration sensor, a distance sensor, a proximity light sensor, a fingerprint sensor, a temperature sensor, a touch sensor, an ambient light sensor, a bone conduction sensor, and the like.
  • the structure shown in this embodiment does not constitute a specific limitation on the sending end/receiving end.
  • the transmitting end/receiving end may include more or less components than shown, or combine certain components, or separate certain components, or arrange different components.
  • the illustrated components can be realized in hardware, software or a combination of software and hardware.
  • the processor 810 may include one or more processing units, for example: the processor 810 may include an application processor (application processor, AP), a Modem, a graphics processing unit (graphics processing unit, GPU), an image signal processor (image signal processor) , ISP), controller, video codec, digital signal processor (digital signal processor, DSP), baseband processor, and/or neural network processor (neural-network processing unit, NPU), etc. Wherein, different processing units may be independent devices, or may be integrated in one or more processors.
  • application processor application processor, AP
  • Modem graphics processing unit
  • GPU graphics processing unit
  • image signal processor image signal processor
  • ISP image signal processor
  • controller video codec
  • digital signal processor digital signal processor
  • DSP digital signal processor
  • baseband processor baseband processor
  • neural network processor neural-network processing unit
  • the wireless communication function of the sending end/receiving end can be realized by the antenna 1, the antenna 2, the mobile communication module 850, the wireless communication module 860, a modem, and a baseband processor.
  • Antenna 1 and Antenna 2 are used to transmit and receive electromagnetic wave signals.
  • Each antenna in the transmitter/receiver can be used to cover single or multiple communication frequency bands. Different antennas can also be multiplexed to improve the utilization of the antennas.
  • the mobile communication module 850 can provide wireless communication solutions including 2G/3G/4G/5G/6G applied on the sending end/receiving end.
  • antenna 1 and the antenna 2 can be used for transmitting or receiving signals at the transmitting end/receiving end.
  • antenna 1 and/or antenna 2 may include a transmitter and/or a receiver as shown in FIG. 7 .
  • the wireless communication module 860 can provide wireless local area networks (wireless local area networks, WLAN) (such as wireless fidelity (Wi-Fi) network), bluetooth (bluetooth, BT), global Wireless communication solutions such as global navigation satellite system (GNSS), frequency modulation (FM), near field communication (NFC), and infrared (IR).
  • the wireless communication module 860 may be one or more devices integrating at least one communication processing module.
  • the wireless communication module 860 receives electromagnetic waves via the antenna 2 , frequency-modulates and filters the electromagnetic wave signals, and sends the processed signals to the processor 810 .
  • the wireless communication module 860 can also receive the signal to be sent from the processor 810, frequency-modulate it, amplify it, and convert it into electromagnetic waves through the antenna 2 to radiate out.
  • the external memory interface 820 can be used to connect an external memory card, such as a Micro SD card, to expand the storage capacity of the sending end/receiving end.
  • an external memory card such as a Micro SD card
  • Internal memory 821 may be used to store computer-executable program code, which includes instructions.
  • the processor 810 executes the instructions stored in the internal memory 821 to execute various functional applications and data processing of the sending end/receiving end.
  • an operating system such as an iOS operating system, an Android operating system, and a Windows operating system, runs on the above-mentioned components. Applications can be installed and run on this operating system. In some other embodiments, there may be multiple operating systems running in the sending end/receiving end.
  • the hardware modules included in the sending end/receiving end shown in FIG. 8 are described only as examples, and do not limit the specific structure of the sending end/receiving end.
  • the sending end/receiving end provided in the embodiment of the present application may also include other hardware modules that have an interactive relationship with the hardware modules shown in the figure, which are not specifically limited here.
  • the sending end/receiving end may also include a flashlight, a miniature projection device, and the like.
  • the sending end/receiving end is a PC, then the sending end/receiving end may also include components such as a keyboard and a mouse.
  • the solution provided by the embodiment of the present application introduces an undersampling digital predistortion device based on coefficient (also called parameter) perception in the transmitter (that is, a non-linear Linear correction device, hereinafter referred to as digital pre-distortion device).
  • digital pre-distortion device based on coefficient (also called parameter) perception in the transmitter (that is, a non-linear Linear correction device, hereinafter referred to as digital pre-distortion device).
  • the digital predistortion device includes a basis function generation module 900, a DPD 910, a DAC 920-1, a DAC 920-2, an integral ADC 930, and a quadrature modulator (quadrature modulator, QMod) 940, quadrature demodulator (quadrature demodulator, QDMod) 950, PA 960, auxiliary circuit (multiplier 970-1 and multiplier 970-2 shown in FIG. 9 ), coupler 980.
  • a quadrature modulator quadrature modulator, QMod
  • QDMod quadrature demodulator
  • PA 960 auxiliary circuit
  • auxiliary circuit multiplier 970-1 and multiplier 970-2 shown in FIG. 9
  • the digital predistortion device may further include an attenuator 990 for preset attenuating the coupled signal within a specified frequency range.
  • a nonlinear correction method provided in an embodiment of the present application may be implemented based on the digital predistortion device shown in FIG. 9 .
  • a nonlinear correction method provided in the embodiment of the present application may mainly include the following four steps:
  • Step 1 Generate a regression matrix and perform orthogonalization on the regression matrix in the digital domain.
  • performing orthogonal processing on the regression matrix in the digital domain is used to facilitate the subsequent correlation of the output signal with the parameters of the power amplifier model.
  • the above step 1 can be performed by the DPD 910.
  • Step 2 Generate an orthogonal basis function in the analog domain and multiply it with the output signal by an analog multiplier.
  • the orthogonal basis functions are used to correlate the output signal with the parameters of the power amplifier model.
  • the above step 2 may be performed by the basis function generation module 900 .
  • the output signal refers to the signal after QDMod 950 quadrature demodulation.
  • Step 3 Process the product output by the analog multiplier through the analog integrator.
  • Step 4 Extract the power amplifier model parameters output by the analog integrator according to actual requirements, so as to realize undersampling of the power amplifier model parameters.
  • a non-linear correction method provided in the embodiment of the present application may include the following S901-S914:
  • the DPD 910 performs digital pre-distortion on the input signal x(n) based on the first pre-distortion parameter, and outputs x I '(n) and x Q '(n).
  • the first predistortion parameter is an initial predistortion parameter.
  • the initial predistortion parameters can be preset in DPD 910.
  • the first predistortion parameter is the DPD parameter obtained in the previous training.
  • the training of the DPD parameters may be implemented based on the nonlinear correction method provided by the embodiment of the present application during the last signal transmission.
  • DAC 920-1 performs digital-to-analog conversion on x I '(n) and x Q '(n), and outputs x I (t) and x Q (t).
  • QMod 940 performs quadrature modulation on x I (t) and x Q (t), outputs x′(t), and feeds it into PA 960 .
  • quadrature modulation includes up-hand up-conversion.
  • PA 960 outputs y(t) after performing power amplification on x'(t).
  • the coupler 980 couples the output signal y(t) of the PA 960 to output y 1 (t).
  • the attenuator 990 performs preset attenuation on y 1 (t), and outputs y 2 (t).
  • QDMod 950 performs quadrature demodulation on y 2 (t), and outputs y 3 (t).
  • y 3 (t) includes I channel signal y I (t) and Q channel signal y Q (t).
  • quadrature demodulation includes quadrature down-conversion.
  • the basis function generation module 900 generates a regression matrix based on the input signal x(n)
  • P is the order of the regression matrix
  • M is related to the historical input signal.
  • b [b 1,0 ,...,b p,m ,...,b P,M ] T .
  • b p, m are regression matrix parameters.
  • the basis function generation module 900 pairs the regression matrix Orthogonal transformation is performed to obtain an orthogonal regression matrix ⁇ .
  • U is an orthogonal projection matrix composed of eigenvectors.
  • the DPD 910 can perform regression matrix Carry out the eigenvalue decomposition shown in the following formula 2 to obtain U and ⁇ :
  • the basis function generating module 900 constructs a power amplifier forward modeling formula according to the orthogonal regression matrix ⁇ .
  • the forward modeling formula of the power amplifier is as the following formula 3:
  • c [c 1 , . . . , c k , . . . , c K ].
  • ⁇ k is the time series of the kth basis function of the orthogonal regression matrix, and the subscripts I and or Q represent the real part and imaginary part of the signal, respectively.
  • T int is the integration time corresponding to N sampling points.
  • the basis function generation module 900 generates a basis function matrix z(n) based on the forward modeling formula of the power amplifier.
  • z(n) includes I-way z I (n) and Q-way z Q (n).
  • DAC 920-2 performs digital-to-analog conversion on z I (n) and z Q (n), and outputs z I (t) and z Q (t).
  • the multiplier 970-1 multiplies z I (t) with the output signal y I (t) of the QDMod 950; the multiplier 970-2 multiplies z Q (t) with the output signal y Q (t) of the QDMod 950 take.
  • the output signal of multiplier 970-1 is z I (t) y I (t);
  • the output signal of multiplier 970-2 The output signal is z Q (t) y Q (t).
  • z I (t)y I (t) ⁇ k -1 ⁇ I,k (t)y I (t)
  • z Q (t)y Q (t) ⁇ k -1 ⁇ Q,k ( t)y Q (t).
  • the integrating ADC 930 integrates the output signals of the multiplier 970-1 and the multiplier 970-2 according to a preset period, so as to extract power amplifier model parameters.
  • the preset period is T int .
  • T int satisfies:
  • N int is a preset value
  • N int is related to the number of parameters of the power amplifier model and/or the performance of the transmitter.
  • Ts is the sampling period in the case of full sampling.
  • the output signal of the integral ADC 930 includes an I-channel signal and a Q-channel signal.
  • I channel signal is Q channel signal is
  • z I (t) and z Q (t) can be determined specifically as follows:
  • the integral ADC 930 can realize the extraction of each parameter of the power amplifier model in a time-division manner according to actual needs.
  • the integrating ADC 930 integrates the output signals of the multipliers 970-1 and 970-2 according to the preset period T int , that is, for each integration interval, only one point needs to be sampled, and the integral
  • T int the preset period
  • the process of integrating the output signals of the multipliers 970-1 and 970-2 by the integrating ADC 930 can realize undersampling with a minimum multiple of N int .
  • the integral ADC 930 can implement under-sampling of the parameters of the power amplifier model according to actual needs.
  • FIG. 11 shows performance parameters corresponding to different multiples of undersampling.
  • the larger N int is, the smaller the sampling rate (Sa/s), the larger the normalized minimum mean square error (NMSE) (in dB), and the larger the error vector magnitude (error The larger the vector magnitude (EVM), the larger the adjacent channel power ratio (ACPR).
  • FIG. 11 is only used as an example of simulation performance parameters under a specific condition, and is only used as a reference.
  • the specific performance parameters that can be realized by actual undersampling depend on specific conditions.
  • the nonlinearity of the PA is quasi-time-varying, and the corresponding nonlinear coefficient is slowly varying. Therefore, in some embodiments, the above-mentioned integral ADC 930 can be a low-speed ADC. By using a low-speed ADC instead of a high-speed ADC, the cost of PA model parameter extraction can be reduced.
  • the non-linear correction method provided by the embodiment of the present application can estimate the power amplifier output in the case of full sampling, and then train the DPD parameters according to the estimated power amplifier output in the case of full sampling .
  • the power amplifier output y' in the case of full sampling can be calculated according to the following formula 4:
  • c' is the parameter of the power amplifier model under the condition of full sampling.
  • the DPD parameters may be trained according to the estimated power amplifier output under the condition of full sampling based on a traditional indirect learning structure or a direct learning structure.
  • the embodiment of the present application does not limit the specific method.
  • specific method and process of training DPD parameters reference may be made to conventional technologies, which will not be repeated here.
  • nonlinear correction method by introducing a digital pre-distortion device based on coefficient (also called parameter) perception in the transmitter, by generating a regression matrix, performing orthogonalization processing on the regression matrix, and generating an orthogonal The basis function, obtaining the output signal, correlating the output signal with the parameters of the power amplifier model according to the generated orthogonal basis function, sampling the output signal to realize the extraction of the parameters of the power amplifier model and realizing the prediction of the power amplifier output under the condition of full sampling, and then
  • the DPD parameters are trained according to actual needs to improve the nonlinear correction performance of the digital predistortion device and solve the nonlinear distortion problem of the transmitter.
  • a power amplifier forward modeling manner divided into frequency bands may also be used.
  • an auxiliary circuit including the integral ADC 930 shown in Figure 12, the multiplier 970-1, the multiplier 970-2, the multiplier 970-3 and the band-limiting filter 970-4 can be used to extract the power amplifier model parameters by frequency division .
  • the band-limit filter 970-4 can filter signals according to preset frequency band parameters.
  • the preset frequency band parameters include the bandwidth of the band-limiting filter 970-4.
  • ⁇ m is the eigenvalue matrix corresponding to the frequency band m
  • ⁇ m diag( ⁇ m,1 ,..., ⁇ m,k ,..., ⁇ m,K ).
  • a power amplifier forward modeling formula (such as the following formula 6) can be constructed to obtain the frequency band m.
  • c m [c m,1 ,...,c m,k ,...,c m,K ].
  • the real part c I, m, k and imaginary part c Q, m, k of c m are:
  • the basis function generating module 900 can generate the basis function matrix z m (n) of the frequency band m based on the power amplifier forward modeling formula of the frequency band m.
  • z m (n) includes I-way z I,m (n) and Q-way z Q,m (n).
  • DAC 920-2 performs digital-to-analog conversion on z I,m (n) and z Q,m (n), and can output z m (t).
  • z m (t) includes real part z I,m (t) and imaginary part z Q,m (t). in:
  • the multiplier 970-3 performs a frequency shift of -mfs/M on the signal y 3 (t), and inputs the frequency-shifted signal to the band-limiting filter 970-4.
  • the band-limiting filter 970-4 filters signals according to preset frequency band setting parameters.
  • the output of the band-limiting filter includes the I-channel signal y I,m (t) and the Q-channel signal y Q,m (t).
  • the multiplier 970-1 multiplies z I,m (t) with the output signal y I,m (t) of the QDMod 950; the multiplier 970-2 multiplies z Q, m (t) is multiplied by the output signal y Q,m (t) of QDMod 950 .
  • the output signal of the multiplier 970-1 is z I, m (t) y I, m (t); after being processed by the multiplier 970-2, the output signal of the multiplier 970-2
  • the output signal is z Q,m (t)y Q,m (t).
  • z I,m (t)y I,m (t) ⁇ m,k -1 ⁇ I,m,k (t)y I,m (t)
  • z Q,m (t)y Q, m (t) ⁇ k,m ⁇ 1 ⁇ Q,m,k (t)y Q,m (t).
  • the integrating ADC 930 can perform multiplier 970-1 and multiplier 970- 2 to extract the power amplifier model parameters c I,m,k and/or c Q,m,k of the frequency band m.
  • the nonlinear correction method provided by the embodiment of the present application can estimate the power amplifier output of frequency band m in the case of full sampling, and then according to the estimated full sampling of the frequency band
  • the power amplifier output of m trains the DPD parameters.
  • DPD parameters may be trained based on traditional indirect learning structures or direct learning structures.
  • the power amplifier output y m ' ⁇ m c m ' of the frequency band m under the condition of full sampling.
  • c m ' is the power amplifier model parameter of frequency band m in the case of full sampling.
  • the non-linear correction method provided in the embodiment of the present application may estimate the power amplifier output of the frequency band m in the case of full sampling.
  • the power amplifier output of multiple frequency bands is superimposed after M times upsampling and -mfs/M frequency shift, and the power amplifier output under the full sampling condition can be obtained, and then the DPD parameters can be trained.
  • DPD parameters may be trained based on traditional indirect learning structures or direct learning structures.
  • the bandwidth of the integral DAC 930 can be reduced by M times, thereby allowing the use of low-speed ADCs instead of high-speed ADCs to reduce the cost of power amplifier model parameter extraction.
  • K can be expressed as a quantity related to m, namely K(m), for example, the number of coefficients corresponding to the in-band frequency band such as K(0) can be large, and the number of coefficients corresponding to the out-of-band frequency band, especially the frequency band at the edge of the spectrum, such as K(M/2) can be small, so that The parameters of the power amplifier model can be flexibly selected to reduce the training time of DPD parameters.
  • the nonlinear correction method provided by the embodiment of the present application can be implemented based on a band-limited filter, or can be compatible with a non-band-limited solution.
  • the band-limited nonlinear correction method can reduce the digital sampling rate, but the sampling time is M times.
  • the embodiment of the present application may introduce a time-division DAC mechanism.
  • the method shown in FIG. 9 can be selected to perform nonlinear correction; when the performance of the digital predistortion device is stable, DPD parameters in a stable state can be selected to perform nonlinear correction.
  • time-division DAC mechanism may be implemented by a time-division switch (such as a signal selection time-division switch).
  • FIG. 15 shows a schematic structural diagram of another digital predistortion device.
  • the digital predistortion device includes a time division switch 1501 and a DAC 1502. Wherein, the time division switch 1501 can work in working state 1 or working state 2.
  • the input of the DAC 1502 is the output of the DPA 910 .
  • the DAC 1502 can be used to perform digital-to-analog conversion on x I '(n) and x Q '(n), and output x I (t) and x Q (t).
  • the input of the DAC 1502 may also include the output of the basis function generation module 900 .
  • the DAC 1502 can be used for digital-to-analog conversion of x I '(n) and x Q '(n), outputting x I (t) and x Q (t); and, for z I (n) and z Q (n ) for digital-to-analog conversion, and output z I (t) and z Q (t).
  • the non-linear correction solution based on the time-division switch can also reduce the digital pre-distortion device by one ADC, so the non-linear correction solution based on the time-division switch can also reduce the cost of nonlinear correction.
  • a delayer 1600 may also be introduced in this embodiment of the present application.
  • the delayer 1600 can be an adjustable delayer, so that the delay parameters (such as delay time, precision, etc.) of the delayer can be adjusted according to actual needs.
  • the precision of the delayer is related to the symbol rate Fs of the current signal, for example, the precision of the delayer is 1/(5*Fs).
  • Fig. 15 is only an example of the structure of a digital predistortion device including a time-division switch
  • Fig. 16 is only an example of the structure of a digital pre-distortion device including a delay device.
  • the non-linear correction scheme of can also be adapted to other structures, such as the digital predistortion device with the structure shown in FIG. 12 .
  • the delayer-based nonlinear correction solution provided in the embodiment of the present application may also be applicable to other structures, for example, the digital predistortion device with the structure shown in FIG. 9 or FIG. 12 .
  • serial numbers of the above-mentioned processes do not mean the order of execution, and the order of execution of the processes should be determined by their functions and internal logic, and should not be implemented in this application.
  • the implementation of the examples constitutes no limitation.
  • the non-linear correction device includes corresponding hardware structures and/or software modules for performing various functions.
  • the present application can be implemented in the form of hardware or a combination of hardware and computer software in combination with the units and algorithm steps of each example described in the embodiments disclosed herein. Whether a certain function is executed by hardware or computer software drives hardware depends on the specific application and design constraints of the technical solution. Skilled artisans may use different methods to implement the described functions for each specific application, but such implementation should not be regarded as exceeding the scope of the present application.
  • the nonlinear correction device can be divided into functional modules.
  • each functional module can be divided corresponding to each function, or two or more functions can be integrated into one processing module.
  • the above-mentioned integrated modules can be implemented in the form of hardware or in the form of software function modules. It should be noted that the division of modules in the embodiment of the present application is schematic, and is only a logical function division, and there may be other division methods in actual implementation.
  • each module in the non-linear correction device may be implemented in the form of software and/or hardware, which is not specifically limited.
  • electronic equipment is presented in the form of functional modules.
  • the "module” here may refer to an application-specific integrated circuit ASIC, a circuit, a processor and memory executing one or more software or firmware programs, an integrated logic circuit, and/or other devices that can provide the above-mentioned functions.
  • the computer program product includes one or more computer instructions.
  • the computer can be a general purpose computer, a special purpose computer, a computer network, or other programmable devices.
  • the computer instructions may be stored in or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from a website, computer, server or data center Transmission to another website site, computer, server or data center by wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.).
  • the computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or a data center that includes one or more available mediums.
  • the available medium can be a magnetic medium, (such as a floppy disk, a hard disk, etc. , tape), optical media (such as digital video disk (digital video disk, DVD)), or semiconductor media (such as solid state disk (SSD)), etc.
  • the steps of the methods or algorithms described in conjunction with the embodiments of the present application may be implemented in hardware, or may be implemented in a manner in which a processor executes software instructions.
  • the software instructions can be composed of corresponding software modules, and the software modules can be stored in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, mobile hard disk, CD-ROM or any other form of storage known in the art medium.
  • An exemplary storage medium is coupled to the processor such the processor can read information from, and write information to, the storage medium.
  • the storage medium may also be a component of the processor.
  • the processor and storage medium can be located in the ASIC. Alternatively, the ASIC may be located in the electronic device.
  • the processor and the storage medium can also exist in the nonlinear correction device as discrete components.

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Abstract

The present application relates to the technical field of signal processing, and discloses a nonlinear correction method, apparatus and system, capable of improving the nonlinear correction performance of a pre-distortion apparatus. According to the solution disclosed by the present application, a digital pre-distortion apparatus based on coefficient perception is introduced into a transmitter, and the prediction of power amplifier output at full sampling is achieved by generating a regression matrix, performing orthogonalization processing on the regression matrix, generating an orthogonal basis function, obtaining an output signal, associating the output signal with parameters of a power amplifier model according to the generated orthogonal basis function, and sampling the output signal to extract the parameters of the power amplifier model, such that nonlinear correction parameters, such as pre-distortion parameters, are trained according to actual requirements, thereby improving the nonlinear correction performance of the digital pre-distortion apparatus, and solving the nonlinear distortion problem of the transmitter.

Description

一种非线性校正方法、装置及***A nonlinear correction method, device and system
本申请要求于2021年12月23日提交国家知识产权局、申请号为202111592222.3、申请名称为“一种非线性校正方法、装置及***”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。This application claims the priority of the Chinese patent application filed with the State Intellectual Property Office on December 23, 2021, with the application number 202111592222.3 and the application title "A Nonlinear Correction Method, Device and System", the entire contents of which are incorporated by reference in this application.
技术领域technical field
本申请实施例涉及信号处理技术领域，尤其涉及一种非线性校正方法、装置及***。The embodiments of the present application relate to the technical field of signal processing, and in particular to a nonlinear correction method, device and system.
背景技术Background technique
为了实现大容量和高速率的无线通信，以满足爆发式增长的用户需求，通信***提供了愈来愈高的信号带宽和愈来愈复杂的调制方式。但是，这将导致通信信号具有较高的峰值平均功率比(peak-to-average power ratio，PAPR)，简称峰均比。In order to realize large-capacity and high-speed wireless communication to meet the explosive growth of user needs, the communication system provides increasingly higher signal bandwidth and more and more complex modulation methods. However, this will cause the communication signal to have a high peak-to-average power ratio (PAPR), referred to as peak-to-average ratio.
以图1所示正交频分复用(orthogonal frequency division multiplexing，OFDM)通信技术为例，由于OFDM符号是由多个独立经过调制的子载波信号(如图1所示
Figure PCTCN2022141085-appb-000001
Figure PCTCN2022141085-appb-000002
)叠加而成的，当各个子载波相位相同或者相近时，叠加信号便会受到相同初始相位信号的调制，从而产生较大的瞬时功率峰值，由此进一步带来较高的PAPR。 Take the orthogonal frequency division multiplexing (orthogonal frequency division multiplexing, OFDM) communication technology shown in Figure 1 as an example, since the OFDM symbol is composed of multiple independently modulated subcarrier signals (as shown in Figure 1
Figure PCTCN2022141085-appb-000001
Figure PCTCN2022141085-appb-000002
) are superimposed, when the phases of each subcarrier are the same or close, the superimposed signal will be modulated by the same initial phase signal, resulting in a larger instantaneous power peak, which further leads to a higher PAPR.
可以理解，功率放大器(power amplifier，PA)是发射机的重要组件，其天然地带有非线性特性。在输入信号的平均功率相同时，PAPR较高的输入信号对PA的非线性更加敏感，极易加剧信号的非线性失真。信号的非线性失真不仅会使频谱扩展从而造成临近信道干扰，还会恶化发射信号的误差向量幅度(error vector magnitude，EVM)，增加接收机的误码率，以及使PA的工作点产生回退从而降低发射机的效率。因此，高PAPR已经成为大容量、高速率通信***的一个主要技术阻碍。It can be understood that a power amplifier (power amplifier, PA) is an important component of a transmitter, and it naturally has nonlinear characteristics. When the average power of the input signal is the same, the input signal with higher PAPR is more sensitive to the nonlinearity of the PA, which can easily aggravate the nonlinear distortion of the signal. The nonlinear distortion of the signal will not only spread the spectrum to cause adjacent channel interference, but also deteriorate the error vector magnitude (EVM) of the transmitted signal, increase the bit error rate of the receiver, and cause the operating point of the PA to roll back Thereby reducing the efficiency of the transmitter. Therefore, high PAPR has become a major technical obstacle for high-capacity, high-speed communication systems.
发明内容Contents of the invention
本申请提供一种非线性校正方法、装置及***，可以提高预失真装置的非线性校正性能。The present application provides a nonlinear correction method, device and system, which can improve the nonlinear correction performance of a predistortion device.
为达到上述目的，本申请实施例采用如下技术方案：In order to achieve the above purpose, the embodiment of the present application adopts the following technical solutions:
第一方面，提供一种非线性校正方法，该方法包括：对第一信号进行预设处理，得到第二信号；基于上述第一信号生成正交回归矩阵；根据该正交回归矩阵，构建得到功率放大器(PA)前向建模公式；根据该PA前向建模公式生成正交基函数；通过对该正交基函数和上述第二信号的乘积进行积分，获取PA模型参数；根据该PA模型参数调整非线性校正参数。In the first aspect, a non-linear correction method is provided, the method includes: performing preset processing on the first signal to obtain the second signal; generating an orthogonal regression matrix based on the first signal; and constructing the obtained orthogonal regression matrix according to the orthogonal regression matrix Power amplifier (PA) forward modeling formula; Generate orthogonal basis function according to this PA forward modeling formula; By integrating the product of this orthogonal basis function and above-mentioned second signal, obtain PA model parameter; According to this PA Model Parameters adjusts the nonlinearity correction parameters.
上述第一方面提供的方案，通过生成正交回归矩阵、生成正交基函数、根据生成正交基函数将输出信号与功放模型的参数相关联、对输出信号进行采样以实现对功放模型参数的提取实现对满采样情况下的功放输出的预测，进而根据实际需求对非线性校正参数，如预失真参数进行训练，以提高数字预失真装置的非线性校正性能，解决发射机的非线性失真问题。In the solution provided by the first aspect above, by generating an orthogonal regression matrix, generating an orthogonal basis function, associating the output signal with the parameters of the power amplifier model according to the generated orthogonal basis function, and sampling the output signal, the parameters of the power amplifier model are realized. The extraction realizes the prediction of the output of the power amplifier under the condition of full sampling, and then according to the actual demand, the nonlinear correction parameters, such as the pre-distortion parameters, are trained to improve the nonlinear correction performance of the digital pre-distortion device and solve the nonlinear distortion problem of the transmitter .
在一种可能的实现方式中，上述非线性校正参数是数字预失真(digital pre-distortion，DPD)参数。作为一种示例，本申请提供的非线性校正方法可以基于DPD装置实现，其中，非线性校正的核心在于进行DPD参数训练和调整。In a possible implementation manner, the above-mentioned nonlinear correction parameter is a digital pre-distortion (digital pre-distortion, DPD) parameter. As an example, the nonlinear correction method provided in the present application may be implemented based on a DPD device, wherein the core of the nonlinear correction lies in performing DPD parameter training and adjustment.
在一种可能的实现方式中，上述通过对正交基函数和第二信号的乘积进行积分，获取PA模型参数，包括：将正交基函数与第二信号的I路信号和Q路信号分别相乘，获取I路乘积和Q路乘积；根据预设周期对I路乘积和Q路乘积进行积分，以获取PA模型参数。通过进行I路信号和Q路信号上述处理，可以实现对PA模型各个参数的提取，以便后续进行满采 样情况下的功放输出估计，进而根据估计的满采样情况下的功放输出训练DPD参数。In a possible implementation, the PA model parameters are obtained by integrating the product of the orthogonal basis function and the second signal, including: integrating the orthogonal basis function and the I-channel signal and the Q-channel signal of the second signal, respectively Multiply to obtain the I-way product and the Q-way product; integrate the I-way product and the Q-way product according to a preset period to obtain PA model parameters. Through the above-mentioned processing of the I-channel signal and the Q-channel signal, the extraction of various parameters of the PA model can be realized, so as to estimate the output of the power amplifier in the case of full sampling, and then train the DPD parameters according to the estimated output of the power amplifier in the case of full sampling.
在一种可能的实现方式中，上述预设周期为T int，T int满足：T int≥N int Ts；其中，N int为预设值，N int与PA模型参数的个数和/或发射机的性能相关，Ts为满采样情况下的采样周期。通过根据与PA模型参数个数和/或发射机性能相关的预设周期实现对PA模型各个参数的提取，可以使提取的PA模型参数更加具有参考价格，从而有利于DPD参数的训练。 In a possible implementation, the above preset period is T int , and T int satisfies: T int ≥ N int Ts; wherein, N int is a preset value, and N int is related to the number of PA model parameters and/or emission It is related to the performance of the machine, and Ts is the sampling period in the case of full sampling. By realizing the extraction of each parameter of the PA model according to the preset period related to the number of PA model parameters and/or the performance of the transmitter, the extracted PA model parameters can be more referenced, thereby facilitating the training of DPD parameters.
在一种可能的实现方式中，上述根据预设周期对I路乘积和Q路乘积进行积分，以获取PA模型参数，包括：在第一时刻对I路乘积和Q路乘积进行积分，获取第一PA模型参数，其中第一时刻满足第一条件；在第二时刻对I路乘积和Q路乘积进行积分，获取第二PA模型参数，其中第二时刻满足第二条件。示例性的，第一时刻满足(2k-2)T int≤t＜(2k-1)T int，第一PA模型参数如PA模型参数的实部；第二时刻满足(2k-1)T int≤t＜2kT int，第二PA模型参数如PA模型参数的实部。通过时分的方式便可以实现对PA模型各个参数的提取。 In a possible implementation manner, the above-mentioned integration of the I-way product and the Q-way product according to the preset period to obtain the PA model parameters includes: integrating the I-way product and the Q-way product at the first moment to obtain the first A PA model parameter, where the first condition is met at the first moment; and the I-way product and the Q-way product are integrated at the second moment to obtain a second PA model parameter, where the second condition is met at the second moment. Exemplarily, the first moment satisfies (2k-2)T int ≤ t<(2k-1)T int , the first PA model parameter is the real part of the PA model parameter; the second moment satisfies (2k-1)T int ≤t<2kT int , the second PA model parameter is the real part of the PA model parameter. The extraction of each parameter of the PA model can be realized by means of time division.
在一种可能的实现方式中，上述第一信号是输入信号中预设频段的信号。作为一种示例，本申请提供的方法支持分频段提取PA模型参数，以降低DPD参数的训练时间。In a possible implementation manner, the above-mentioned first signal is a signal of a preset frequency band in the input signal. As an example, the method provided in this application supports the extraction of PA model parameters by frequency bands, so as to reduce the training time of DPD parameters.
在一种可能的实现方式中，上述方法还包括：对输入信号中所有频段的信号，采用与第一信号相同的方法进行非线性校正参数调整。作为一种示例，本申请提供的方法支持分频段提取PA模型参数，以降低DPD参数的训练时间。In a possible implementation manner, the above method further includes: performing nonlinear correction parameter adjustment on signals of all frequency bands in the input signal using the same method as that of the first signal. As an example, the method provided in this application supports the extraction of PA model parameters by frequency bands, so as to reduce the training time of DPD parameters.
在一种可能的实现方式中，上述方法还包括：在非线性校正参数稳定时，根据调整后的非线性校正参数进行信号发射前的信号非线性校正。通过该方法，可以在进行非线性校正时，综合考虑采样率和采样时间。另外，该方法还可以降低非线性校正时的ADC成本。In a possible implementation manner, the above method further includes: when the nonlinear correction parameter is stable, performing signal nonlinear correction before signal transmission according to the adjusted nonlinear correction parameter. Through this method, the sampling rate and sampling time can be considered comprehensively when performing nonlinear correction. In addition, this method can also reduce the ADC cost when nonlinear correction.
在一种可能的实现方式中，上述将正交基函数与第二信号的I路信号和Q路信号分别相乘，获取I路乘积和Q路乘积，包括：同步将正交基函数与第二信号的I路信号和Q路信号分别相乘，获取I路乘积和Q路乘积。示例性的，可以通过延时器实现I路信号和Q路信号的同步处理。In a possible implementation manner, the above-mentioned multiplication of the orthogonal basis function with the I-channel signal and the Q-channel signal of the second signal to obtain the I-channel product and the Q-channel product includes: synchronously multiplying the orthogonal basis function with the first The I-channel signal and the Q-channel signal of the two signals are respectively multiplied to obtain the I-channel product and the Q-channel product. Exemplarily, the synchronous processing of the I-channel signal and the Q-channel signal may be implemented through a delayer.
在一种可能的实现方式中，上述基于第一信号生成正交回归矩阵，包括：基于第一信号生成回归矩阵；对回归矩阵进行正交变换，得到正交回归矩阵。In a possible implementation manner, the generating the orthogonal regression matrix based on the first signal includes: generating the regression matrix based on the first signal; performing orthogonal transformation on the regression matrix to obtain the orthogonal regression matrix.
在一种可能的实现方式中，上述对第一信号进行预设处理，得到第二信号，包括：对第一信号分别进行数字预失真、数模转换、正交调制以及功率放大后得到第二信号。In a possible implementation manner, the preset processing of the first signal to obtain the second signal includes: performing digital pre-distortion, digital-to-analog conversion, quadrature modulation, and power amplification on the first signal to obtain the second signal. Signal.
第二方面，提供一种非线性校正装置，该非线性校正装置包括：发射模块，用于对第一信号进行预设处理，得到第二信号；基函数生成模块，用于：基于上述第一信号生成正交回归矩阵；根据该正交回归矩阵，构建得到功率放大器(PA)前向建模公式；以及，根据该PA前向建模公式生成正交基函数；积分模拟数字转换模块，用于通过对该正交基函数和上述第二信号的乘积进行积分，获取PA模型参数；预失真模块，用于根据PA模型参数调整非线性校正参数。In a second aspect, a nonlinear correction device is provided, which includes: a transmitting module, configured to perform preset processing on the first signal to obtain a second signal; a basis function generation module, configured to: based on the above-mentioned first The signal generates an orthogonal regression matrix; according to the orthogonal regression matrix, a power amplifier (PA) forward modeling formula is constructed; and, according to the PA forward modeling formula, an orthogonal basis function is generated; the integral analog-to-digital conversion module is used The PA model parameters are obtained by integrating the product of the orthogonal basis function and the above-mentioned second signal; the pre-distortion module is used for adjusting the nonlinear correction parameter according to the PA model parameters.
示例性的，发射模块可以包括数字模拟转换器(digital-to-analog converter，DAC)和PA。Exemplarily, the transmitting module may include a digital-to-analog converter (digital-to-analog converter, DAC) and a PA.
示例性的，积分模拟数字转换模块如积分DAC。Exemplarily, the integral analog-to-digital conversion module is such as an integral DAC.
上述第二方面提供的方案，通过生成正交回归矩阵、生成正交基函数、根据生成正交基函数将输出信号与功放模型的参数相关联、对输出信号进行采样以实现对功放模型参数的提取实现对满采样情况下的功放输出的预测，进而根据实际需求对非线性校正参数，如预失真参数进行训练，以提高数字预失真装置的非线性校正性能，解决发射机的非线性失真问题。In the solution provided by the second aspect above, by generating an orthogonal regression matrix, generating an orthogonal basis function, associating the output signal with the parameters of the power amplifier model according to the generated orthogonal basis function, and sampling the output signal, the parameters of the power amplifier model are realized. The extraction realizes the prediction of the output of the power amplifier under the condition of full sampling, and then according to the actual demand, the nonlinear correction parameters, such as the pre-distortion parameters, are trained to improve the nonlinear correction performance of the digital pre-distortion device and solve the nonlinear distortion problem of the transmitter .
在一种可能的实现方式中，上述非线性校正参数是DPD参数。作为一种示例，本申请提供的非线性校正方法可以基于DPD装置实现，其中，非线性校正的核心在于进行DPD参数 训练和调整。In a possible implementation manner, the above-mentioned nonlinear correction parameters are DPD parameters. As an example, the nonlinear correction method provided in this application can be implemented based on a DPD device, wherein the core of the nonlinear correction lies in the training and adjustment of DPD parameters.
在一种可能的实现方式中，上述积分模拟数字转换模块具体用于：将正交基函数与第二信号的I路信号和Q路信号分别相乘，获取I路乘积和Q路乘积；根据预设周期对I路乘积和Q路乘积进行积分，以获取PA模型参数。通过进行I路信号和Q路信号上述处理，可以实现对PA模型各个参数的提取，以便后续进行满采样情况下的功放输出估计，进而根据估计的满采样情况下的功放输出训练DPD参数。In a possible implementation, the above integral analog-to-digital conversion module is specifically configured to: multiply the orthogonal basis function with the I-channel signal and the Q-channel signal of the second signal to obtain the I-channel product and the Q-channel product; according to The I-way product and the Q-way product are integrated at a preset period to obtain PA model parameters. Through the above-mentioned processing of the I-channel signal and the Q-channel signal, the extraction of various parameters of the PA model can be realized, so as to estimate the output of the power amplifier in the case of full sampling, and then train the DPD parameters according to the estimated output of the power amplifier in the case of full sampling.
在一种可能的实现方式中，上述预设周期为T int，T int满足：T int≥N intTs；其中，N int为预设值，N int与PA模型参数的个数和/或发射机的性能相关，Ts为满采样情况下的采样周期。通过根据与PA模型参数个数和/或发射机性能相关的预设周期实现对PA模型各个参数的提取，可以使提取的PA模型参数更加具有参考价格，从而有利于DPD参数的训练。 In a possible implementation, the above preset period is T int , and T int satisfies: T int ≥ N int Ts; wherein, N int is a preset value, and N int is related to the number of PA model parameters and/or emission It is related to the performance of the machine, and Ts is the sampling period in the case of full sampling. By realizing the extraction of each parameter of the PA model according to the preset period related to the number of PA model parameters and/or the performance of the transmitter, the extracted PA model parameters can be more referenced, thereby facilitating the training of DPD parameters.
在一种可能的实现方式中，上述积分模拟数字转换模块具体用于：在第一时刻对I路乘积和Q路乘积进行积分，获取第一PA模型参数，其中第一时刻满足第一条件；在第二时刻对I路乘积和Q路乘积进行积分，获取第二PA模型参数，其中第二时刻满足第二条件。示例性的，第一时刻满足(2k-2)T int≤t＜(2k-1)T int，第一PA模型参数如PA模型参数的实部；第二时刻满足(2k-1)T int≤t＜2kT int，第二PA模型参数如PA模型参数的实部。通过时分的方式便可以实现对PA模型各个参数的提取。 In a possible implementation manner, the above integral analog-to-digital conversion module is specifically configured to: integrate the I-way product and the Q-way product at the first moment to obtain the first PA model parameter, wherein the first condition is met at the first moment; Integrate the I-way product and the Q-way product at a second moment to obtain a second PA model parameter, wherein the second condition is satisfied at the second moment. Exemplarily, the first moment satisfies (2k-2)T int ≤ t<(2k-1)T int , the first PA model parameter is the real part of the PA model parameter; the second moment satisfies (2k-1)T int ≤t<2kT int , the second PA model parameter is the real part of the PA model parameter. The extraction of each parameter of the PA model can be realized by means of time division.
在一种可能的实现方式中，上述第一信号是输入信号中预设频段的信号。作为一种示例，本申请提供的方法支持分频段提取PA模型参数，以降低DPD参数的训练时间。In a possible implementation manner, the above-mentioned first signal is a signal of a preset frequency band in the input signal. As an example, the method provided in this application supports the extraction of PA model parameters by frequency bands, so as to reduce the training time of DPD parameters.
在一种可能的实现方式中，上述预失真模块还用于：对输入信号中所有频段的信号，采用与第一信号相同的方法进行非线性校正参数调整。作为一种示例，本申请提供的方法支持分频段提取PA模型参数，以降低DPD参数的训练时间。In a possible implementation manner, the above-mentioned pre-distortion module is further configured to: perform non-linear correction parameter adjustment on signals of all frequency bands in the input signal using the same method as that of the first signal. As an example, the method provided in this application supports the extraction of PA model parameters by frequency bands, so as to reduce the training time of DPD parameters.
在一种可能的实现方式中，上述预失真模块还用于：在非线性校正参数稳定时，根据调整后的非线性校正参数进行信号发射前的信号非线性校正。通过该方法，可以在进行非线性校正时，综合考虑采样率和采样时间。另外，该方法还可以降低非线性校正时的ADC成本。In a possible implementation manner, the above-mentioned pre-distortion module is further configured to perform signal nonlinear correction before signal transmission according to the adjusted nonlinear correction parameter when the nonlinear correction parameter is stable. Through this method, the sampling rate and sampling time can be considered comprehensively when performing nonlinear correction. In addition, this method can also reduce the ADC cost when nonlinear correction.
在一种可能的实现方式中，上述积分模拟数字转换模块具体用于：同步将正交基函数与第二信号的I路信号和Q路信号分别相乘，获取I路乘积和Q路乘积。示例性的，可以通过延时器实现I路信号和Q路信号的同步处理。In a possible implementation manner, the above integral analog-to-digital conversion module is specifically configured to: synchronously multiply the orthogonal basis function with the I-channel signal and the Q-channel signal of the second signal to obtain the I-channel product and the Q-channel product. Exemplarily, the synchronous processing of the I-channel signal and the Q-channel signal may be implemented through a delayer.
在一种可能的实现方式中，上述基函数生成模块具体用于：基于第一信号生成回归矩阵；对回归矩阵进行正交变换，得到正交回归矩阵。In a possible implementation manner, the above-mentioned basis function generation module is specifically configured to: generate a regression matrix based on the first signal; and perform an orthogonal transformation on the regression matrix to obtain an orthogonal regression matrix.
在一种可能的实现方式中，上述发射模块具体用于：对第一信号分别进行数字预失真、数模转换、正交调制以及功率放大后得到第二信号。In a possible implementation manner, the transmitting module is specifically configured to: perform digital predistortion, digital-to-analog conversion, quadrature modulation, and power amplification on the first signal to obtain the second signal.
第三方面，提供一种计算机可读存储介质，该计算机可读存储介质上存储有计算机程序代码，该计算机程序代码被处理器执行时实现如第一方面任一种可能的实现方式中的方法。In a third aspect, a computer-readable storage medium is provided, where computer program code is stored on the computer-readable storage medium, and when the computer program code is executed by a processor, the method in any possible implementation manner of the first aspect is implemented .
第四方面，提供一种芯片***，该芯片***包括处理器、存储器，存储器中存储有计算机程序代码；所述计算机程序代码被所述处理器执行时，实现如第一方面任一种可能的实现方式中的方法。该芯片***可以由芯片构成，也可以包含芯片和其他分立器件。In a fourth aspect, a chip system is provided, the chip system includes a processor, a memory, and a computer program code is stored in the memory; when the computer program code is executed by the processor, any possible method in the implementation. The system-on-a-chip may consist of chips, or may include chips and other discrete devices.
第五方面，提供一种计算机程序产品，当其在计算机上运行时，使得实现如第一方面任一种可能的实现方式中的方法。In a fifth aspect, a computer program product is provided, which, when running on a computer, enables the method in any possible implementation manner of the first aspect to be implemented.
附图说明Description of drawings
图1为本申请实施例提供的一种OFDM通信技术通信过程示意图；FIG. 1 is a schematic diagram of an OFDM communication technology communication process provided by an embodiment of the present application;
图2为本申请实施例提供的一种OFDM信号时域波形图；FIG. 2 is a time-domain waveform diagram of an OFDM signal provided by an embodiment of the present application;
图3为本申请实施例提供的一种功率放大器(PA)的非线性特性示意图；FIG. 3 is a schematic diagram of nonlinear characteristics of a power amplifier (PA) provided in an embodiment of the present application;
图4为本申请实施例提供的发射机的工作过程示意图一；FIG. 4 is a first schematic diagram of the working process of the transmitter provided by the embodiment of the present application;
图5为本申请实施例提供的发射机的工作过程示意图二；FIG. 5 is a second schematic diagram of the working process of the transmitter provided by the embodiment of the present application;
图6为本申请实施例提供的发射机的工作过程示意图三；FIG. 6 is a third schematic diagram of the working process of the transmitter provided by the embodiment of the present application;
图7为本申请实施例提供的一种通信场景示例图；FIG. 7 is an example diagram of a communication scenario provided by an embodiment of the present application;
图8为本申请实施例提供的一种发送端/接收端的硬件结构示意图；FIG. 8 is a schematic diagram of a hardware structure of a sending end/receiving end provided by an embodiment of the present application;
图9为本申请实施例提供的发射机的工作过程示意图四；FIG. 9 is a schematic diagram 4 of the working process of the transmitter provided by the embodiment of the present application;
图10为本申请实施例提供的一种功放模型参数采样过程示意图；FIG. 10 is a schematic diagram of a parameter sampling process of a power amplifier model provided by an embodiment of the present application;
图11为本申请实施例提供的一种不同倍数的欠采样所对应的性能参数示例图；FIG. 11 is an example diagram of performance parameters corresponding to different multiples of undersampling provided in the embodiment of the present application;
图12为本申请实施例提供的发射机的工作过程示意图五；FIG. 12 is a schematic diagram 5 of the working process of the transmitter provided by the embodiment of the present application;
图13为本申请实施例提供的一种带限滤波器的带宽示例图；FIG. 13 is an example diagram of a bandwidth of a band-limit filter provided in an embodiment of the present application;
图14为本申请实施例提供的另一种功放模型参数采样过程示意图；FIG. 14 is a schematic diagram of another power amplifier model parameter sampling process provided by the embodiment of the present application;
图15为本申请实施例提供的发射机的工作过程示意图六；FIG. 15 is a sixth schematic diagram of the working process of the transmitter provided by the embodiment of the present application;
图16为本申请实施例提供的发射机的工作过程示意图七。FIG. 16 is a seventh schematic diagram of the working process of the transmitter provided by the embodiment of the present application.
具体实施方式Detailed ways
下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行描述。其中，在本申请实施例的描述中，除非另有说明，“/”表示或的意思，例如，A/B可以表示A或B；本文中的“和/或”仅仅是一种描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A，同时存在A和B，单独存在B这三种情况。另外，在本申请实施例的描述中，“多个”是指两个或多于两个。The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. Among them, in the description of the embodiments of this application, unless otherwise specified, "/" means or means, for example, A/B can mean A or B; "and/or" in this article is only a description of associated objects The association relationship of indicates that there may be three kinds of relationships, for example, A and/or B may indicate: A exists alone, A and B exist simultaneously, and B exists independently. In addition, in the description of the embodiments of the present application, "plurality" refers to two or more than two.
以下，术语“第一”、“第二”仅用于描述目的，而不能理解为指示或暗示相对重要性或者隐含指明所指示的技术特征的数量。由此，限定有“第一”、“第二”的特征可以明示或者隐含地包括一个或者更多个该特征。在本实施例的描述中，除非另有说明，“多个”的含义是两个或两个以上。Hereinafter, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, a feature defined as "first" and "second" may explicitly or implicitly include one or more of these features. In the description of this embodiment, unless otherwise specified, "plurality" means two or more.
为方便理解，以下对本申请涉及的几个术语做简单介绍。For the convenience of understanding, several terms involved in this application are briefly introduced below.
1、正交频分复用(OFDM)1. Orthogonal Frequency Division Multiplexing (OFDM)
OFDM的主要思想是发送端将信道分成若干正交子信道，将高速数据信号转换成并行的多条低速子数据流(如图1所示
Figure PCTCN2022141085-appb-000003
)，通过多个子信道进行传输。对应的，如图1所示，接收端可以采用相关技术解析获取多条低速子数据流，以此减少子信道之间的相互干扰。由于每个子信道上的信号带宽小于信道的相关带宽，因此每个子信道上可以看成平坦性衰落，从而可以消除码间串扰。并且，由于每个子信道的带宽仅仅是原信道带宽的一小部分，因此信道均衡变得相对容易。 The main idea of OFDM is that the sending end divides the channel into several orthogonal sub-channels, and converts high-speed data signals into multiple parallel low-speed sub-data streams (as shown in Figure 1
Figure PCTCN2022141085-appb-000003
), transmitted through multiple sub-channels. Correspondingly, as shown in FIG. 1 , the receiving end may use related technologies to analyze and obtain multiple low-speed sub-data streams, so as to reduce mutual interference between sub-channels. Since the signal bandwidth on each sub-channel is smaller than the correlation bandwidth of the channel, each sub-channel can be regarded as flat fading, so that the intersymbol interference can be eliminated. Moreover, since the bandwidth of each sub-channel is only a small part of the original channel bandwidth, channel equalization becomes relatively easy.
2、峰均比(PAPR)2. Peak-to-average ratio (PAPR)
PAPR是一种对信号的测量参数。例如，PAPR是对无线发射机输入幅度动态范围的一种测量，PAPR可以作为用于衡量发射机性能的指标之一。通常，PAPR用于表征信号的振幅与有效值(如均方根值(root meam square，RMS))的比值。PAPR is a measurement parameter for a signal. For example, PAPR is a measurement of the dynamic range of the input amplitude of a wireless transmitter, and PAPR can be used as one of the indicators used to measure the performance of the transmitter. Usually, PAPR is used to characterize the ratio of the amplitude of the signal to the effective value (such as root mean square (RMS)).
以OFDM通信技术为例，PAPR的定义如下：Taking OFDM communication technology as an example, PAPR is defined as follows:
Figure PCTCN2022141085-appb-000004
Figure PCTCN2022141085-appb-000004
其中，x(t)表示OFDM信号，T表示累积时间周期。请参考图2，图2示出了一种OFDM 信号示意图。其中，图1所示OFDM peak即max 0≤t＜Tx(t)，OFDM mean即mean 0≤t＜Tx(t)。 Among them, x(t) represents the OFDM signal, and T represents the accumulation time period. Please refer to FIG. 2, which shows a schematic diagram of an OFDM signal. Wherein, the OFDM peak shown in FIG. 1 is max 0≤t<T x(t), and the OFDM mean is mean 0≤t<T x(t).
3、非线性失真3. Nonlinear distortion
输出信号相对于输入信号产生非线性变形，从而带来无益的干扰信号，影响信息的正确传递和接收，这种现象称为非线性失真。The output signal is nonlinearly deformed relative to the input signal, thereby bringing unhelpful interference signals and affecting the correct transmission and reception of information. This phenomenon is called nonlinear distortion.
示例性的，功率放大器(PA)具有非线性失真的特征，即PA具有非线性特性。示例性的，对于PA来说，在预设输入功率范围(如图3所示P in1范围)内，输入信号与输入信号呈线性关系。如图3所示，输出功率P out1与输入功率P in1呈线性关系。但是，当输入功率大于预设阈值(如图3所示P in2)，输出功率逐渐呈现非线性。如图3所示，输出功率P out2与输入功率P’ in2呈非线性关系，偏离了理想情况下的值P in2。 Exemplarily, the power amplifier (PA) has a characteristic of nonlinear distortion, that is, the PA has nonlinear characteristics. Exemplarily, for the PA, within a preset input power range (the range of P in1 shown in FIG. 3 ), the input signal has a linear relationship with the input signal. As shown in FIG. 3 , the output power P out1 has a linear relationship with the input power P in1 . However, when the input power is greater than a preset threshold (P in2 shown in FIG. 3 ), the output power gradually becomes non-linear. As shown in FIG. 3 , the output power P out2 has a nonlinear relationship with the input power P' in2 , which deviates from the ideal value P in2 .
由于功率放大器(PA)是发射机的重要组件，因此发射机具有非线性特性。为了校正发射机的非线性，以提高发射机的效率与通信质量。作为一种实现方式，可以通过引入了数字预失真(digital pre-distortion，DPD)技术校正发射机的非线性。其中，DPD的原理是：通过提供与功率放大器(PA)的失真特性相当，但是功能相反的非线性特性，使得预失真元件可以校正功率放大器(PA)的非线性，从而使对输入信号的综合处理结果与输入信号满足线性关系。Since the power amplifier (PA) is an important component of the transmitter, the transmitter has nonlinear characteristics. In order to correct the nonlinearity of the transmitter to improve the efficiency and communication quality of the transmitter. As an implementation manner, the nonlinearity of the transmitter can be corrected by introducing a digital pre-distortion (digital pre-distortion, DPD) technology. Among them, the principle of DPD is: by providing a nonlinear characteristic that is equivalent to the distortion characteristic of the power amplifier (PA), but the function is opposite, the predistortion element can correct the nonlinearity of the power amplifier (PA), so that the synthesis of the input signal The processing result satisfies a linear relationship with the input signal.
作为一种示例，可以通过将预失真元件(Predistorter)与功率放大器(PA)级联，以校正发射机的非线性。其中，预失真元件(Predistorter)可以提供与功率放大器(PA)的失真特性相当，但是功能相反的非线性特性，使得预失真元件可以校正功率放大器(PA)的非线性。请参考图4，图4示出了本申请实施例提供的一种发射机的工作过程示意图。其中，图4所示x(t)是输入信号，z(t)是输入信号经过DPD预失真后的输出信号，y(t)是预失真后的信号经过功率放大之后的输出信号。如图4所示，经过预失真元件和功率放大器(PA)的综合处理，输出信号y(t)与输入信号x(t)满足线性关系。As an example, the non-linearity of the transmitter can be corrected by cascading a predistorter element (Predistorter) and a power amplifier (PA). Wherein, the predistorter can provide nonlinear characteristics equivalent to the distortion characteristics of the power amplifier (PA), but the function is opposite, so that the predistorter can correct the nonlinearity of the power amplifier (PA). Please refer to FIG. 4 , which shows a schematic diagram of a working process of a transmitter provided in an embodiment of the present application. Wherein, x(t) shown in FIG. 4 is the input signal, z(t) is the output signal after the input signal is pre-distorted by DPD, and y(t) is the output signal after the pre-distortion signal is amplified. As shown in Fig. 4, after comprehensive processing of the pre-distortion element and the power amplifier (PA), the output signal y(t) and the input signal x(t) satisfy a linear relationship.
作为另一种示例，可以通过将集成有非线性校正功能的带限滤波器(如低通滤波器)与功率放大器(PA)级联，以校正一定带宽范围之内的非线性。请参考图5，图5示出了本申请实施例提供的另一种发射机的工作过程示意图。其中，图5所示x(n)是输入信号，y(n)是经过功率放大之后的输出信号，y BL(n)是经过带限滤波DPD之后的输出信号。如图5所示，经过带限滤波器的处理，可以修正带限滤波器带宽范围内信号的非线性。 As another example, a power amplifier (PA) can be cascaded with a band-limit filter integrated with a nonlinear correction function (such as a low-pass filter) to correct nonlinearities within a certain bandwidth. Please refer to FIG. 5 , which shows a schematic diagram of a working process of another transmitter provided by an embodiment of the present application. Wherein, x(n) shown in FIG. 5 is an input signal, y(n) is an output signal after power amplification, and y BL (n) is an output signal after band-limit filtering DPD. As shown in Figure 5, after being processed by the band-limit filter, the nonlinearity of the signal within the bandwidth of the band-limit filter can be corrected.
作为另一种示例，可以基于随机解调进行欠采样预失真。如图6所示，可以通过生成周期为采样间隔、数值为0或1的伪随机信号。在输入信号x(t)经过DPD预失真、数字模拟转换器(digital-to-analog converter，DAC)的数模转换和功率放大器(PA)的功率放大输出信号y(t)之后，可以基于伪随机信号进行随机采样获取随机采样信号y R(t)，并经过带限滤波器和模数转换得到输出信号y ’(t)。进一步的，基于图6所示方法，还可以进一步根据经过预失真后的信号与输出信号y ’(t)对预失真相关参数就行调整，以进一步提高DPD的非线性校正性能。 As another example, undersampling predistortion may be based on random demodulation. As shown in FIG. 6 , a pseudo-random signal whose period is a sampling interval and whose value is 0 or 1 can be generated. After the input signal x(t) undergoes DPD predistortion, digital-to-analog converter (DAC) digital-to-analog conversion and power amplifier (PA) power amplified output signal y(t), it can be based on pseudo The random signal is randomly sampled to obtain a random sampling signal y R (t), and an output signal y ' (t) is obtained through a band-limited filter and analog-to-digital conversion. Further, based on the method shown in FIG. 6 , the predistortion related parameters can be further adjusted according to the predistorted signal and the output signal y ' (t), so as to further improve the nonlinear correction performance of the DPD.
但是，常规的非线性校正方法均存在或多或少的问题。例如，基于上述图5所示非线性校正方法，无法实现对带限滤波器的带宽范围以外的信号的非线性校正。又如，基于图6所示非线性校正方法，在DAC带宽有限的情况下，模拟伪随机信号失真严重，随机解调性能较差化。However, there are more or less problems in conventional nonlinear correction methods. For example, based on the above-mentioned nonlinear correction method shown in FIG. 5 , the nonlinear correction of signals outside the bandwidth range of the band-limiting filter cannot be realized. As another example, based on the nonlinear correction method shown in FIG. 6 , when the bandwidth of the DAC is limited, the analog pseudo-random signal is severely distorted, and the performance of random demodulation is poor.
为了提高发射机的非线性校正性能，解决发射机的非线性失真问题，本申请实施例提供一种非线性校正方法，该方法可以通过在算法层面对回归矩阵进行正交化，使功率放大器(PA)前向建模过程中功放模型各个参数可以独立提取，以实现支持功放模型参数的适应性 设置和调整。在一些实施例中，本申请实施例提供的一种非线性校正方法还可以通过引入乘法器和积分器，时分提取功放模型的各个参数，以实现支持欠采样无限大倍数的设置和调整。In order to improve the nonlinear correction performance of the transmitter and solve the nonlinear distortion problem of the transmitter, an embodiment of the present application provides a nonlinear correction method, which can make the power amplifier ( In the forward modeling process of PA), each parameter of the power amplifier model can be extracted independently, so as to realize the adaptive setting and adjustment of the parameters of the power amplifier model. In some embodiments, the non-linear correction method provided by the embodiment of the present application can also time-divisionally extract various parameters of the power amplifier model by introducing a multiplier and an integrator, so as to support the setting and adjustment of infinite multiples of undersampling.
在本申请实施例中，用于进行信号传输的通信***可以包括发送端、接收端和通信信道。其中，通信信道如无线信道或者有线信道，本申请实施例不限定。其中，无线信道如用于无线传输的大气、真空、水等介质。有线信道如用于传输信号的光纤、铜线等介质。In the embodiment of the present application, a communication system for signal transmission may include a sending end, a receiving end, and a communication channel. Wherein, the communication channel, such as a wireless channel or a wired channel, is not limited in this embodiment of the present application. Among them, the wireless channel is such as air, vacuum, water and other media used for wireless transmission. Wired channels such as fiber optics, copper wires, and other media used to transmit signals.
其中，在本申请实施例中，发送端和接收端可以是网络设备或者终端设备。例如，发送端是网络设备，接收端是终端设备。又如，发送端是终端设备，接收端是网络设备。又如，发送端和接收端都是网络设备。又如，发送端和接收端都是终端设备。本申请不限定发送端和接收端的具体功能和结构。Wherein, in the embodiment of the present application, the sending end and the receiving end may be network devices or terminal devices. For example, the sending end is a network device, and the receiving end is a terminal device. In another example, the sending end is a terminal device, and the receiving end is a network device. In another example, both the sending end and the receiving end are network devices. In another example, both the sending end and the receiving end are terminal devices. This application does not limit the specific functions and structures of the sending end and the receiving end.
示例性的，网络设备如接入网(access network，AN)或无线接入网(radio access network，RAN)。例如，AN/RAN可以是各种形式的基站，例如：宏基站，微基站(也称为“小站”)，分散单元-控制单元(distribute unit-control unit，DU-CU)等。另外，上述基站还可以是云无线接入网络(cloud radio access network，CRAN)场景下的无线控制器，或者中继站、接入点、车载设备、可穿戴设备或者未来演进的公共陆地移动网络(public land mobile network，PLMN)网络中的网络设备等。AN/RAN也可以是宽带网络业务网关(broadband network gateway，BNG)，汇聚交换机，非3GPP接入设备等。本申请实施例对AN/RAN的具体形态和结构不做限定。如，在采用不同的无线接入技术的***中，具备基站功能的设备的名称可能会有所不同。例如，基站可以是LTE中的演进型通用陆地无线接入网(evolved universal terrestrial radio access network，E-UTRAN)设备，如演进型节点B(evolutional NodeB，eNB或e-NodeB)，也可以是5G***中的下一代无线接入网(next generation radio access network，NG-RAN)设备(如gNB)等。Exemplarily, the network device is an access network (access network, AN) or a radio access network (radio access network, RAN). For example, the AN/RAN may be various forms of base stations, such as macro base stations, micro base stations (also called "small cells"), distributed unit-control units (distribute unit-control unit, DU-CU), etc. In addition, the above-mentioned base station may also be a wireless controller in a cloud radio access network (CRAN) scenario, or a relay station, an access point, a vehicle-mounted device, a wearable device, or a future evolved public land mobile network (public land mobile network, PLMN) network equipment, etc. AN/RAN can also be a broadband network gateway (broadband network gateway, BNG), aggregation switch, non-3GPP access device, etc. The embodiment of the present application does not limit the specific form and structure of the AN/RAN. For example, in systems adopting different wireless access technologies, the names of equipment with base station functions may be different. For example, the base station can be an evolved universal terrestrial radio access network (evolved universal terrestrial radio access network, E-UTRAN) device in LTE, such as an evolved node B (evolutional NodeB, eNB or e-NodeB), or it can be a 5G Next generation radio access network (NG-RAN) equipment (such as gNB) in the system.
示例性的，终端设备如具有通信功能的桌面型设备、膝上型设备、手持型设备、可穿戴设备、智能家居设备、计算设备和车载型设备等。例如，上网本、平板电脑、智能手表、个人计算机(personal computer，PC)、超级移动个人计算机(ultra-mobile personal computer，UMPC)、智能相机、上网本、个人数字助理(personal digital assistant，PDA)、蜂窝电话、无绳电话、会话启动协议(session initiation protocol，SIP)电话、无线本地环路(wireless local loop，WLL)站、便携式多媒体播放器(portable multimedia player，PMP)、(augmented reality，AR)/虚拟现实(virtual reality，VR)设备、飞行器上的无线设备、机器人上的无线设备、工业控制中的无线设备、远程医疗中的无线设备、智能电网中的无线设备、智慧城市(Smart City)中的无线设备、智慧家庭(smart home)中的无线设备等。本申请实施例对终端设备的具体类型和结构等不作限定。Exemplarily, the terminal device is a desktop device, a laptop device, a handheld device, a wearable device, a smart home device, a computing device, a vehicle-mounted device, etc. with a communication function. For example, netbooks, tablets, smart watches, personal computers (PCs), ultra-mobile personal computers (UMPCs), smart cameras, netbooks, personal digital assistants (PDAs), cellular Telephone, cordless phone, session initiation protocol (SIP) phone, wireless local loop (WLL) station, portable multimedia player (PMP), (augmented reality, AR)/virtual Reality (virtual reality, VR) devices, wireless devices on aircraft, wireless devices on robots, wireless devices in industrial control, wireless devices in telemedicine, wireless devices in smart grids, and wireless devices in smart cities (Smart City) Wireless devices, wireless devices in smart homes, etc. The embodiment of the present application does not limit the specific type and structure of the terminal device.
需要说明的是，本申请实施例中使用的“***”和“网络”这样的用语可以互换使用。It should be noted that terms such as "system" and "network" used in the embodiments of the present application may be used interchangeably.
在本申请实施例中，“终端设备”、“移动台(mobile station，MS)”、“用户终端(user terminal)”、“用户装置(user equipment，UE)”以及“终端”这样的用语可以互换使用。终端设备有时也被本领域技术人员以用户台、移动单元、用户单元、无线单元、远程单元、移动设备、无线设备、无线通信设备、远程设备、移动用户台、接入终端、移动终端、无线终端、远程终端、手持机、用户代理、移动客户端、客户端或者若干其它适当的用语来称呼。In this embodiment of the application, terms such as "terminal equipment", "mobile station (mobile station, MS)", "user terminal (user terminal)", "user equipment (user equipment, UE)" and "terminal" may be used Used interchangeably. Terminal equipment is also sometimes referred to by those skilled in the art as subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other appropriate term.
此外，本申请实施例中的基站也可以用用户终端来替换。例如，对于将基站和终端设备间的通信替换为多个用户终端间(device-to-device，D2D)的通信的结构，也可以应用本公开的各方式/实施方式。此时，可以将基站所具有的功能当作用户终端所具有的功能。此外，“上行”和“下行”等文字也可以替换为“侧”。例如，上行信道也可以替换为侧信道。同样，本申请 实施例中的用户终端也可以用基站来替换。此时，可以将上述的用户终端所具有的功能当作基站所具有的功能。In addition, the base station in the embodiment of the present application may also be replaced by a user terminal. For example, various modes/embodiments of the present disclosure may also be applied to a configuration in which communication between a base station and a terminal device is replaced with communication between multiple user terminals (device-to-device, D2D). At this time, the functions of the base station can be regarded as the functions of the user terminal. Also, words like "up" and "down" can be replaced with "side". For example, uplink channels can also be replaced by side channels. Similarly, the user terminal in the embodiment of the present application can also be replaced by a base station. At this time, the above-mentioned functions of the user terminal may be regarded as functions of the base station.
在本申请实施例中，发送端中包括发射机，接收端中包括接收机。其中，发送端中的发射机用于支持发送端发射信号，接收端中的接收机用于支持接收端接收信号。In this embodiment of the present application, the sending end includes a transmitter, and the receiving end includes a receiver. Wherein, the transmitter in the sending end is used to support the sending end to transmit signals, and the receiver in the receiving end is used to support the receiving end to receive signals.
在一些可能的结构中，发送端中还可以包括接收机，接收端中还包括发射机。其中，发送端中的接收机用于支持发送端接收信号，接收端中的发射机用于支持接收端发射信号。In some possible structures, the sending end may further include a receiver, and the receiving end may further include a transmitter. Wherein, the receiver in the sending end is used to support the sending end to receive signals, and the transmitter in the receiving end is used to support the receiving end to transmit signals.
作为一种示例，请参考图7，图7示出了本申请实施例提供的一种通信场景示意图。其中，图7所示通信场景中的通信***包括位于发送端中的发射机、位于接收端中的接收机和通信信道(其中图7中未示出发送端和接收端)。As an example, please refer to FIG. 7 , which shows a schematic diagram of a communication scenario provided by an embodiment of the present application. Wherein, the communication system in the communication scenario shown in FIG. 7 includes a transmitter at the sending end, a receiver at the receiving end, and a communication channel (the sending end and the receiving end are not shown in FIG. 7 ).
如图7所示，发射机包括基带处理单元710、DPD 720、DAC 730、发射中射频740和PA750。接收机包括接收中射频760、模拟数字转换器(analog-to-digital converter，ADC)770和基带处理单元780。As shown in FIG. 7 , the transmitter includes a baseband processing unit 710, a DPD 720, a DAC 730, a transmitting radio frequency 740, and a PA750. The receiver includes a receiving radio frequency 760 , an analog-to-digital converter (analog-to-digital converter, ADC) 770 and a baseband processing unit 780 .
其中，发射机中的基带处理单元710主要用于进行信息的调制、成帧、滤波整型、预失真校正等。DPD 720主要用于进行PA 750的非线性化预校正。DAC 730主要用于进行数模转换。发射中射频740主要用于进行将基带信号调制到射频信号、信号滤波等。PA 750主要用于对信号进行功率放大。Wherein, the baseband processing unit 710 in the transmitter is mainly used for information modulation, framing, filtering and shaping, pre-distortion correction, and the like. DPD 720 is mainly used for nonlinear pre-correction of PA 750. DAC 730 is mainly used for digital-to-analog conversion. During transmission, the radio frequency 740 is mainly used for modulating the baseband signal into a radio frequency signal, and filtering the signal. PA 750 is mainly used for power amplification of signals.
接收机中的接收中射频760主要用于将接收到的射频信号下变频到低频或者基带。ADC770主要用于进行模数转换。基带处理单元780主要用于恢复基带信号的恢复，如同步、均衡等。The receiving radio frequency 760 in the receiver is mainly used for down-converting the received radio frequency signal to low frequency or baseband. ADC770 is mainly used for analog-to-digital conversion. The baseband processing unit 780 is mainly used to restore the baseband signal, such as synchronization and equalization.
在一些实施例中，图7所示发射机还可以包括编码单元，接收机还可以包括解码单元。其中，编码单元主要用于对信号进行信息的纠错、编码、交织等。解码单元主要用于对信号进行解密、解码等。In some embodiments, the transmitter shown in FIG. 7 may further include an encoding unit, and the receiver may further include a decoding unit. Wherein, the coding unit is mainly used for error correction, coding, interleaving, etc. of information on the signal. The decoding unit is mainly used for deciphering and decoding signals.
需要说明的是，图7仅作为一种通信架构示例，本申请不限定通信***的具体通信架构。例如，在本申请实施例中，通信***还可以包括其他单元或者模块。又如，在本申请实施例中，发射机或者接收机还可以包括比图7中更多的通信器件或者不包括图7中某一通信器件。It should be noted that FIG. 7 is only an example of a communication architecture, and the present application does not limit the specific communication architecture of the communication system. For example, in the embodiment of the present application, the communication system may further include other units or modules. As another example, in the embodiment of the present application, the transmitter or the receiver may include more communication devices than those shown in FIG. 7 or may not include a certain communication device shown in FIG. 7 .
作为一种示例，请参考图8，图8以终端设备为例，示出了一种发送端/接收端的硬件结构示意图。如图8所示，在一些实施例中，发送端/接收端的结构可以如图8所示，发送端/接收端可以包括：处理器810，外部存储器接口820，内部存储器821，通用串行总线(universal serial bus，USB)接口830，充电管理模块840，电源管理模块841，电池842，天线1，天线2，移动通信模块850，无线通信模块860，音频模块870，扬声器870A，受话器870B，麦克风870C，耳机接口870D，传感器模块880，按键890，马达891，指示器892，摄像头893，显示屏894，以及用户标识模块(subscriber identification module，SIM)卡接口895等。其中传感器模块880可以包括压力传感器，陀螺仪传感器，气压传感器，磁传感器，加速度传感器，距离传感器，接近光传感器，指纹传感器，温度传感器，触摸传感器，环境光传感器，骨传导传感器等。As an example, please refer to FIG. 8 . FIG. 8 takes a terminal device as an example and shows a schematic diagram of a hardware structure of a sending end/receiving end. As shown in Figure 8, in some embodiments, the structure of the sending end/receiving end can be as shown in Figure 8, and the sending end/receiving end can include: a processor 810, an external memory interface 820, an internal memory 821, a universal serial bus (universal serial bus, USB) interface 830, charging management module 840, power management module 841, battery 842, antenna 1, antenna 2, mobile communication module 850, wireless communication module 860, audio module 870, speaker 870A, receiver 870B, microphone 870C, earphone jack 870D, sensor module 880, button 890, motor 891, indicator 892, camera 893, display screen 894, subscriber identification module (subscriber identification module, SIM) card interface 895, etc. The sensor module 880 may include a pressure sensor, a gyroscope sensor, an air pressure sensor, a magnetic sensor, an acceleration sensor, a distance sensor, a proximity light sensor, a fingerprint sensor, a temperature sensor, a touch sensor, an ambient light sensor, a bone conduction sensor, and the like.
可以理解的是，本实施例示意的结构并不构成对发送端/接收端的具体限定。在另一些实施例中，发送端/接收端可以包括比图示更多或更少的部件，或者组合某些部件，或者拆分某些部件，或者不同的部件布置。图示的部件可以以硬件，软件或软件和硬件的组合实现。It can be understood that the structure shown in this embodiment does not constitute a specific limitation on the sending end/receiving end. In some other embodiments, the transmitting end/receiving end may include more or less components than shown, or combine certain components, or separate certain components, or arrange different components. The illustrated components can be realized in hardware, software or a combination of software and hardware.
处理器810可以包括一个或多个处理单元，例如：处理器810可以包括应用处理器(application processor，AP)，Modem，图形处理器(graphics processing unit，GPU)，图像信号处理器(image signal processor，ISP)，控制器，视频编解码器，数字信号处理器(digital signal  processor，DSP)，基带处理器，和/或神经网络处理器(neural-network processing unit，NPU)等。其中，不同的处理单元可以是独立的器件，也可以集成在一个或多个处理器中。The processor 810 may include one or more processing units, for example: the processor 810 may include an application processor (application processor, AP), a Modem, a graphics processing unit (graphics processing unit, GPU), an image signal processor (image signal processor) , ISP), controller, video codec, digital signal processor (digital signal processor, DSP), baseband processor, and/or neural network processor (neural-network processing unit, NPU), etc. Wherein, different processing units may be independent devices, or may be integrated in one or more processors.
发送端/接收端的无线通信功能可以通过天线1，天线2，移动通信模块850，无线通信模块860，调制解调器以及基带处理器等实现。The wireless communication function of the sending end/receiving end can be realized by the antenna 1, the antenna 2, the mobile communication module 850, the wireless communication module 860, a modem, and a baseband processor.
天线1和天线2用于发射和接收电磁波信号。发送端/接收端中的每个天线可用于覆盖单个或多个通信频带。不同的天线还可以复用，以提高天线的利用率。 Antenna 1 and Antenna 2 are used to transmit and receive electromagnetic wave signals. Each antenna in the transmitter/receiver can be used to cover single or multiple communication frequency bands. Different antennas can also be multiplexed to improve the utilization of the antennas.
移动通信模块850可以提供应用在发送端/接收端上的包括2G/3G/4G/5G/6G等无线通信的解决方案。The mobile communication module 850 can provide wireless communication solutions including 2G/3G/4G/5G/6G applied on the sending end/receiving end.
在本申请实施例中，天线1和天线2可用于发送端/接收端发射信号或者接收信号。示例性的，天线1和/或天线2可以包括图7所示发射机和/或接收机。In the embodiment of the present application, the antenna 1 and the antenna 2 can be used for transmitting or receiving signals at the transmitting end/receiving end. Exemplarily, antenna 1 and/or antenna 2 may include a transmitter and/or a receiver as shown in FIG. 7 .
无线通信模块860可以提供应用在发送端/接收端上的包括无线局域网(wireless local area networks，WLAN)(如无线保真(wireless fidelity，Wi-Fi)网络)，蓝牙(bluetooth，BT)，全球导航卫星***(global navigation satellite system，GNSS)，调频(frequency modulation，FM)，近距离无线通信技术(near field communication，NFC)，红外技术(infrared，IR)等无线通信的解决方案。无线通信模块860可以是集成至少一个通信处理模块的一个或多个器件。无线通信模块860经由天线2接收电磁波，将电磁波信号调频以及滤波处理，将处理后的信号发送到处理器810。无线通信模块860还可以从处理器810接收待发送的信号，对其进行调频，放大，经天线2转为电磁波辐射出去。The wireless communication module 860 can provide wireless local area networks (wireless local area networks, WLAN) (such as wireless fidelity (Wi-Fi) network), bluetooth (bluetooth, BT), global Wireless communication solutions such as global navigation satellite system (GNSS), frequency modulation (FM), near field communication (NFC), and infrared (IR). The wireless communication module 860 may be one or more devices integrating at least one communication processing module. The wireless communication module 860 receives electromagnetic waves via the antenna 2 , frequency-modulates and filters the electromagnetic wave signals, and sends the processed signals to the processor 810 . The wireless communication module 860 can also receive the signal to be sent from the processor 810, frequency-modulate it, amplify it, and convert it into electromagnetic waves through the antenna 2 to radiate out.
外部存储器接口820可以用于连接外部存储卡，例如Micro SD卡，实现扩展发送端/接收端的存储能力。The external memory interface 820 can be used to connect an external memory card, such as a Micro SD card, to expand the storage capacity of the sending end/receiving end.
内部存储器821可以用于存储计算机可执行程序代码，所述可执行程序代码包括指令。处理器810通过运行存储在内部存储器821的指令，从而执行发送端/接收端的各种功能应用以及数据处理。Internal memory 821 may be used to store computer-executable program code, which includes instructions. The processor 810 executes the instructions stored in the internal memory 821 to execute various functional applications and data processing of the sending end/receiving end.
另外，在上述部件之上，运行有操作***，例如iOS操作***，Android操作***，Windows操作***等。在该操作***上可以安装运行应用程序。在另一些实施例中，发送端/接收端内运行的操作***可以有多个。In addition, an operating system, such as an iOS operating system, an Android operating system, and a Windows operating system, runs on the above-mentioned components. Applications can be installed and run on this operating system. In some other embodiments, there may be multiple operating systems running in the sending end/receiving end.
应理解，图8所示发送端/接收端包括的硬件模块只是示例性地描述，并不对发送端/接收端的具体结构做出限定。事实上，本申请实施例提供的发送端/接收端中还可以包含其它与图中示意的硬件模块具有交互关系的其它硬件模块，这里不作具体限定。例如，发送端/接收端还可以包括闪光灯、微型投影装置等。又如，若发送端/接收端是PC，那么发送端/接收端还可以包括键盘、鼠标等部件。It should be understood that the hardware modules included in the sending end/receiving end shown in FIG. 8 are described only as examples, and do not limit the specific structure of the sending end/receiving end. In fact, the sending end/receiving end provided in the embodiment of the present application may also include other hardware modules that have an interactive relationship with the hardware modules shown in the figure, which are not specifically limited here. For example, the sending end/receiving end may also include a flashlight, a miniature projection device, and the like. For another example, if the sending end/receiving end is a PC, then the sending end/receiving end may also include components such as a keyboard and a mouse.
以下将结合附图，对本申请实施例提供的一种非线性校正方法做具体介绍。A nonlinear correction method provided in the embodiment of the present application will be described in detail below with reference to the accompanying drawings.
为了支持发射机在进行信号发射的过程中，校正发射机的非线性，本申请实施例提供的方案在发射机中引入了基于系数(也称参数)感知的欠采样数字预失真装置(即非线性校正装置，以下简称数字预失真装置)。作为一种示例，如图9所示，该数字预失真装置包括基函数生成模块900、DPD 910、DAC 920-1、DAC 920-2、积分ADC 930、正交调制器(quadrature modulator，QMod)940、正交解调器(quadrature demodulator，QDMod)950、PA 960、辅助电路(如图9所示乘法器970-1和乘法器970-2)、耦合器980。In order to support the transmitter to correct the non-linearity of the transmitter during signal transmission, the solution provided by the embodiment of the present application introduces an undersampling digital predistortion device based on coefficient (also called parameter) perception in the transmitter (that is, a non-linear Linear correction device, hereinafter referred to as digital pre-distortion device). As an example, as shown in FIG. 9, the digital predistortion device includes a basis function generation module 900, a DPD 910, a DAC 920-1, a DAC 920-2, an integral ADC 930, and a quadrature modulator (quadrature modulator, QMod) 940, quadrature demodulator (quadrature demodulator, QDMod) 950, PA 960, auxiliary circuit (multiplier 970-1 and multiplier 970-2 shown in FIG. 9 ), coupler 980.
在一些实施例中，为了方便系数提取和训练，如图9所示，数字预失真装置还可以包括衰减器990，用于在指定的频率范围内对耦合信号进行预设衰减。In some embodiments, in order to facilitate coefficient extraction and training, as shown in FIG. 9 , the digital predistortion device may further include an attenuator 990 for preset attenuating the coupled signal within a specified frequency range.
本申请实施例提供的一种非线性校正方法可以基于图9所示数字预失真装置实现。其中， 本申请实施例提供的一种非线性校正方法主要可以包括以下四个步骤：A nonlinear correction method provided in an embodiment of the present application may be implemented based on the digital predistortion device shown in FIG. 9 . Among them, a nonlinear correction method provided in the embodiment of the present application may mainly include the following four steps:
步骤1：生成回归矩阵，并在数字域对回归矩阵进行正交化处理。Step 1: Generate a regression matrix and perform orthogonalization on the regression matrix in the digital domain.
其中，在数字域对回归矩阵进行正交化处理用于方便后续将输出信号与功放模型的参数相关。以图9所示数字预失真装置为例，上述步骤1可以由DPD 910负责。Wherein, performing orthogonal processing on the regression matrix in the digital domain is used to facilitate the subsequent correlation of the output signal with the parameters of the power amplifier model. Taking the digital predistortion device shown in FIG. 9 as an example, the above step 1 can be performed by the DPD 910.
步骤2：在模拟域生成正交基函数，并通过模拟乘法器与输出信号相乘。Step 2: Generate an orthogonal basis function in the analog domain and multiply it with the output signal by an analog multiplier.
其中，正交基函数用于将输出信号与功放模型的参数相关联。Among them, the orthogonal basis functions are used to correlate the output signal with the parameters of the power amplifier model.
以图9所示数字预失真装置为例，上述步骤2可以由基函数生成模块900负责。输出信号是指经过QDMod 950正交解调后的信号。Taking the digital predistortion device shown in FIG. 9 as an example, the above step 2 may be performed by the basis function generation module 900 . The output signal refers to the signal after QDMod 950 quadrature demodulation.
步骤3：通过模拟积分器对模拟乘法器输出的乘积进行处理。Step 3: Process the product output by the analog multiplier through the analog integrator.
步骤4：根据实际需求提取模拟积分器输出的功放模型参数，以实现对功放模型参数的欠采样。Step 4: Extract the power amplifier model parameters output by the analog integrator according to actual requirements, so as to realize undersampling of the power amplifier model parameters.
以输入信号是数字域基带输入信号x(n)为例，如图9所示，输入信号x(n)包括I(in-phase，同相)路信号x I(n)和Q(quadrature，正交)路信号x Q(n)。如图9所示，本申请实施例提供的一种非线性校正方法可以包括以下S901-S914： Taking the input signal as an example of the digital domain baseband input signal x(n), as shown in FIG. Cross) road signal x Q (n). As shown in Figure 9, a non-linear correction method provided in the embodiment of the present application may include the following S901-S914:
S901：DPD 910基于第一预失真参数对输入信号x(n)进行数字预失真，输出x I'(n)和x Q'(n)。 S901: The DPD 910 performs digital pre-distortion on the input signal x(n) based on the first pre-distortion parameter, and outputs x I '(n) and x Q '(n).
例如，第一预失真参数如初始预失真参数。示例性的，初始预失真参数可以预先设置在DPD 910中。For example, the first predistortion parameter is an initial predistortion parameter. Exemplarily, the initial predistortion parameters can be preset in DPD 910.
又如，第一预失真参数如上一次训练得到的DPD参数。示例性的，可以在上一次进行信号发射时，基于本申请实施例提供的非线性校正方法实现对DPD参数的训练。In another example, the first predistortion parameter is the DPD parameter obtained in the previous training. Exemplarily, the training of the DPD parameters may be implemented based on the nonlinear correction method provided by the embodiment of the present application during the last signal transmission.
S902：DAC 920-1对x I'(n)和x Q'(n)进行数模转换，输出x I(t)和x Q(t)。 S902: DAC 920-1 performs digital-to-analog conversion on x I '(n) and x Q '(n), and outputs x I (t) and x Q (t).
S903：QMod 940对x I(t)和x Q(t)进行正交调制，输出x'(t)，并馈入PA 960。 S903: QMod 940 performs quadrature modulation on x I (t) and x Q (t), outputs x′(t), and feeds it into PA 960 .
其中，正交调制包括上交上变频。Wherein, quadrature modulation includes up-hand up-conversion.
S904：PA 960对x'(t)进行功率放大后输出y(t)。S904: PA 960 outputs y(t) after performing power amplification on x'(t).
S905：耦合器980耦合PA 960的输出信号y(t)，输出y 1(t)。 S905: The coupler 980 couples the output signal y(t) of the PA 960 to output y 1 (t).
S906：衰减器990对y 1(t)进行预设衰减，输出y 2(t)。 S906: The attenuator 990 performs preset attenuation on y 1 (t), and outputs y 2 (t).
S907：QDMod 950对y 2(t)进行正交解调，输出y 3(t)。其中，y 3(t)包括I路信号y I(t)和Q路信号y Q(t)。 S907: QDMod 950 performs quadrature demodulation on y 2 (t), and outputs y 3 (t). Wherein, y 3 (t) includes I channel signal y I (t) and Q channel signal y Q (t).
其中，正交解调包括正交下变频。Wherein, quadrature demodulation includes quadrature down-conversion.
S908：基函数生成模块900基于输入信号x(n)生成回归矩阵
Figure PCTCN2022141085-appb-000005
S908: The basis function generation module 900 generates a regression matrix based on the input signal x(n)
Figure PCTCN2022141085-appb-000005
其中，
Figure PCTCN2022141085-appb-000006
满足以下前向建模公式1： in,
Figure PCTCN2022141085-appb-000006
Satisfy the following forward modeling formula 1:
Figure PCTCN2022141085-appb-000007
Figure PCTCN2022141085-appb-000007
其中，上述公式1中，
Figure PCTCN2022141085-appb-000008
P是回归矩阵的阶数，M与历史输入信号相关。
Figure PCTCN2022141085-appb-000009
满足： Among them, in the above formula 1,
Figure PCTCN2022141085-appb-000008
P is the order of the regression matrix, and M is related to the historical input signal.
Figure PCTCN2022141085-appb-000009
satisfy:
Figure PCTCN2022141085-appb-000010
Figure PCTCN2022141085-appb-000010
上述公式1中，y＝[y(0),…,y(n),…,y(N-1)] T。y(n)满足： In the above formula 1, y=[y(0),...,y(n),...,y(N-1)] T . y(n) satisfies:
Figure PCTCN2022141085-appb-000011
Figure PCTCN2022141085-appb-000011
上述公式1中，b＝[b 1,0,…,b p,m,…,b P,M] T。其中，b p,m为回归矩阵参数。 In the above formula 1, b=[b 1,0 ,...,b p,m ,...,b P,M ] T . Among them, b p, m are regression matrix parameters.
S909：基函数生成模块900对回归矩阵
Figure PCTCN2022141085-appb-000012
进行正交变换，得到正交回归矩阵Ψ。 S909: The basis function generation module 900 pairs the regression matrix
Figure PCTCN2022141085-appb-000012
Orthogonal transformation is performed to obtain an orthogonal regression matrix Ψ.
其中，
Figure PCTCN2022141085-appb-000013
U为由特征向量构成的正交投影矩阵。Ψ满足Ψ HΨ＝Σ。 in,
Figure PCTCN2022141085-appb-000013
U is an orthogonal projection matrix composed of eigenvectors. Ψ satisfies Ψ H Ψ = Σ.
示例性的，DPD 910可以对回归矩阵
Figure PCTCN2022141085-appb-000014
进行如下公式2所示特征值分解，从而得到U和Σ： Exemplarily, the DPD 910 can perform regression matrix
Figure PCTCN2022141085-appb-000014
Carry out the eigenvalue decomposition shown in the following formula 2 to obtain U and Σ:
Figure PCTCN2022141085-appb-000015
Figure PCTCN2022141085-appb-000015
其中，上述公式2中，Σ为特征值矩阵，Σ＝diag(λ 1,…,λ k,…,λ K)。K为DPD模型的系数个数,K＝P×(M+1)。 Wherein, in the above formula 2, Σ is an eigenvalue matrix, and Σ=diag(λ 1 ,...,λ k ,...,λ K ). K is the coefficient number of DPD model, K=P×(M+1).
S910：基函数生成模块900根据正交回归矩阵Ψ，构建得到功放前向建模公式。S910: The basis function generating module 900 constructs a power amplifier forward modeling formula according to the orthogonal regression matrix Ψ.
其中，功放前向建模公式如以下公式3：Among them, the forward modeling formula of the power amplifier is as the following formula 3:
y＝Ψc。    (公式3)y=Ψc. (Formula 3)
其中，c为功放模型参数，c满足b＝Uc。Among them, c is a power amplifier model parameter, and c satisfies b=Uc.
可以理解，基于上述前向建模公式(即公式3)，利用最小二乘法可以确定功放模型参数c＝(Ψ HΨ) -1Ψ Hy。其中，c＝[c 1,…,c k,…,c K]。 It can be understood that, based on the above forward modeling formula (that is, formula 3), the power amplifier model parameter c=(Ψ H Ψ) -1 Ψ H y can be determined by using the least square method. Wherein, c=[c 1 , . . . , c k , . . . , c K ].
基于上述公式3可以计算得到：Based on the above formula 3, it can be calculated as follows:
c k＝λ k -1Ψ k Hy c k ＝λ k -1 Ψ k H y
＝λ k -1(Ψ I,k Hy I-Ψ Q,k Hy Q)+jλ k -1(Ψ I,k Hy I+Ψ Q,k Hy Q)。 =λ k -1 (Ψ I,k H y I -Ψ Q,k H y Q )+jλ k -1 (Ψ I,k H y I +Ψ Q,k H y Q ).
其中，Ψ k为正交回归矩阵第k个基函数的时间序列，下标I和或Q分别表示信号的实部和虚部。 Among them, Ψ k is the time series of the kth basis function of the orthogonal regression matrix, and the subscripts I and or Q represent the real part and imaginary part of the signal, respectively.
基于上述c k的计算公式可以得到：上述功放模型参数c k的实部为c I,k，虚部为c Q,k。其中： Based on the calculation formula of c k above, it can be obtained that the real part of the above power amplifier model parameter c k is c I,k , and the imaginary part is c Q,k . in:
Figure PCTCN2022141085-appb-000016
Figure PCTCN2022141085-appb-000016
Figure PCTCN2022141085-appb-000017
Figure PCTCN2022141085-appb-000017
其中，T int为N个采样点对应的积分时间。 Among them, T int is the integration time corresponding to N sampling points.
S911：基函数生成模块900基于功放的前向建模公式生成基函数矩阵z(n)。z(n)包括I路z I(n)和Q路z Q(n)。 S911: The basis function generation module 900 generates a basis function matrix z(n) based on the forward modeling formula of the power amplifier. z(n) includes I-way z I (n) and Q-way z Q (n).
S912：DAC 920-2对z I(n)和z Q(n)进行数模转换，输出z I(t)和z Q(t)。 S912: DAC 920-2 performs digital-to-analog conversion on z I (n) and z Q (n), and outputs z I (t) and z Q (t).
其中，z I(t)＝λ k -1ψ I,k(t),z Q(t)＝-λ k -1ψ Q,k(t)。 Wherein, z I (t) = λ k -1 ψ I,k (t), z Q (t) = -λ k -1 ψ Q,k (t).
S913：乘法器970-1将z I(t)与QDMod 950的输出信号y I(t)相乘；乘法器970-2将z Q(t)与QDMod 950的输出信号y Q(t)相乘。 S913: The multiplier 970-1 multiplies z I (t) with the output signal y I (t) of the QDMod 950; the multiplier 970-2 multiplies z Q (t) with the output signal y Q (t) of the QDMod 950 take.
如图10所示，经过乘法器970-1处理之后，乘法器970-1的输出信号为z I(t)y I(t)；经过乘法器970-2处理之后，乘法器970-2的输出信号为z Q(t)y Q(t)。其中，z I(t)y I(t)＝λ k -1ψ I,k(t)y I(t)，z Q(t)y Q(t)＝λ k -1ψ Q,k(t)y Q(t)。 As shown in Figure 10, after being processed by multiplier 970-1, the output signal of multiplier 970-1 is z I (t) y I (t); After being processed by multiplier 970-2, the output signal of multiplier 970-2 The output signal is z Q (t) y Q (t). Among them, z I (t)y I (t) = λ k -1 ψ I,k (t)y I (t), z Q (t)y Q (t) = λ k -1 ψ Q,k ( t)y Q (t).
S914：积分ADC 930根据预设周期对乘法器970-1和乘法器970-2的输出信号进行积分，以提取功放模型参数。S914: The integrating ADC 930 integrates the output signals of the multiplier 970-1 and the multiplier 970-2 according to a preset period, so as to extract power amplifier model parameters.
其中，预设周期如T int。T int满足： Wherein, the preset period is T int . T int satisfies:
T int≥N int Ts。 T int ≥ N int Ts.
其中，N int为预设值，N int与功放模型参数的个数和/或发射机的性能相关。Ts为满采样情况下的采样周期。 Wherein, N int is a preset value, and N int is related to the number of parameters of the power amplifier model and/or the performance of the transmitter. Ts is the sampling period in the case of full sampling.
如图10所示，经过积分ADC 930处理之后，积分ADC 930的输出信号包括I路信号和Q路信号。其中。I路信号为
Figure PCTCN2022141085-appb-000018
Q路信号为
Figure PCTCN2022141085-appb-000019
As shown in FIG. 10 , after being processed by the integral ADC 930 , the output signal of the integral ADC 930 includes an I-channel signal and a Q-channel signal. in. I channel signal is
Figure PCTCN2022141085-appb-000018
Q channel signal is
Figure PCTCN2022141085-appb-000019
可以理解，上述积分ADC 930输出的I路信号与Q路信号的叠加
Figure PCTCN2022141085-appb-000020
即功放模型参数c k的实部c I,k。积分ADC 930的输出的I路信号与Q路信号的差值
Figure PCTCN2022141085-appb-000021
即功放模型参数c k的虚部c Q,k。因此，积分ADC 930对乘法器970-1和乘法器970-2的输出信号进行积分这一过程等效于对功放模型参数进行采样。 It can be understood that the superposition of the I-channel signal and the Q-channel signal output by the above integral ADC 930
Figure PCTCN2022141085-appb-000020
That is, the real part c I,k of the power amplifier model parameter c k . Integrating the difference between the I channel signal and the Q channel signal of the output of the ADC 930
Figure PCTCN2022141085-appb-000021
That is, the imaginary part c Q,k of the power amplifier model parameter c k . Therefore, the process of integrating the output signals of the multipliers 970-1 and 970-2 by the integrating ADC 930 is equivalent to sampling the parameters of the power amplifier model.
其中，基于预设周期T int，可以确定z I(t)和z Q(t)具体如下： Wherein, based on the preset period T int , z I (t) and z Q (t) can be determined specifically as follows:
Figure PCTCN2022141085-appb-000022
Figure PCTCN2022141085-appb-000022
Figure PCTCN2022141085-appb-000023
Figure PCTCN2022141085-appb-000023
基于上述z I(t)和z Q(t)的计算式可知，当(2k-2)T int≤t＜(2k-1)T int时，积分ADC 930采样的系数为功放模型参数c k的实部c I,k，当(2k-1)T int≤t＜2kT int时，积分ADC 930采样的系数为功放模型参数c k的虚部。因此，积分ADC 930根据实际需求，通过时分的方式便可以实现对功放模型各个参数的提取。 Based on the above calculation formulas of z I (t) and z Q (t), it can be seen that when (2k-2)T int ≤ t<(2k-1)T int , the coefficient sampled by the integral ADC 930 is the power amplifier model parameter c k The real part c I,k of , when (2k-1)T int ≤ t<2kT int , the coefficient sampled by the integral ADC 930 is the imaginary part of the power amplifier model parameter c k . Therefore, the integral ADC 930 can realize the extraction of each parameter of the power amplifier model in a time-division manner according to actual needs.
并且，在本申请实施例中，积分ADC 930根据预设周期T int对乘法器970-1和乘法器970-2的输出信号进行积分，即对于每一个积分区间，只需采样一个点，积分ADC 930的系数感知采样率f int满足： Moreover, in this embodiment of the application, the integrating ADC 930 integrates the output signals of the multipliers 970-1 and 970-2 according to the preset period T int , that is, for each integration interval, only one point needs to be sampled, and the integral The coefficient-aware sampling rate f int of ADC 930 satisfies:
Figure PCTCN2022141085-appb-000024
Figure PCTCN2022141085-appb-000024
因此，积分ADC 930对乘法器970-1和乘法器970-2的输出信号进行积分这一过程可以实现最小倍数为N int的欠采样。基于这种机制，积分ADC 930可以根据实际需求实现对功放模型参数的欠采样。示例性的，请参考图11，图11示出了不同倍数的欠采样所对应的性能参数。如图11所示，N int越大，采样率(Sa/s)越小，归一化最小均方误差(normalized minimum mean square error，NMSE)(单位为dB)越大，误差向量幅度(error vector magnitude，EVM)越大，邻信道功率比(adjacent channel power ratio，ACPR)越大。 Therefore, the process of integrating the output signals of the multipliers 970-1 and 970-2 by the integrating ADC 930 can realize undersampling with a minimum multiple of N int . Based on this mechanism, the integral ADC 930 can implement under-sampling of the parameters of the power amplifier model according to actual needs. For example, please refer to FIG. 11 , which shows performance parameters corresponding to different multiples of undersampling. As shown in Figure 11, the larger N int is, the smaller the sampling rate (Sa/s), the larger the normalized minimum mean square error (NMSE) (in dB), and the larger the error vector magnitude (error The larger the vector magnitude (EVM), the larger the adjacent channel power ratio (ACPR).
需要说明的是，图11仅作为一种特定条件下仿真性能参数示例，仅作为参考，实际欠采样所能实现的具体性能参数视具体情况而定。It should be noted that FIG. 11 is only used as an example of simulation performance parameters under a specific condition, and is only used as a reference. The specific performance parameters that can be realized by actual undersampling depend on specific conditions.
可以理解，通常，PA的非线性是准时变的，对应的非线性系数是慢变的，因此，在一些实施例中，上述积分ADC 930可以是低速ADC。通过使用低速ADC替代高速ADC，可以降低功放模型参数提取的成本。It can be understood that, generally, the nonlinearity of the PA is quasi-time-varying, and the corresponding nonlinear coefficient is slowly varying. Therefore, in some embodiments, the above-mentioned integral ADC 930 can be a low-speed ADC. By using a low-speed ADC instead of a high-speed ADC, the cost of PA model parameter extraction can be reduced.
在获取功放模型参数之后，进一步的，如图9所示，本申请实施例提供的非线性校正方法可以估计满采样情况下的功放输出，进而根据估计的满采样情况下的功放输出训练DPD参数。After obtaining the power amplifier model parameters, further, as shown in FIG. 9 , the non-linear correction method provided by the embodiment of the present application can estimate the power amplifier output in the case of full sampling, and then train the DPD parameters according to the estimated power amplifier output in the case of full sampling .
其中，满采样情况下的功放输出y’可以根据以下公式4计算得到：Among them, the power amplifier output y' in the case of full sampling can be calculated according to the following formula 4:
y’＝Ψc’。    (公式4)y'=Ψc'. (Formula 4)
上述公式4中，c’为满采样情况下功放模型参数。In the above formula 4, c' is the parameter of the power amplifier model under the condition of full sampling.
作为一种示例，本申请实施例提供的非线性校正方法中，可以基于传统的间接学习结构或者直接学习等结构，根据估计的满采样情况下的功放输出训练DPD参数。本申请实施例不限定具体方法，训练DPD参数的具体方法和过程可以参考常规技术，这里不做赘述。As an example, in the non-linear correction method provided in the embodiment of the present application, the DPD parameters may be trained according to the estimated power amplifier output under the condition of full sampling based on a traditional indirect learning structure or a direct learning structure. The embodiment of the present application does not limit the specific method. For the specific method and process of training DPD parameters, reference may be made to conventional technologies, which will not be repeated here.
基于本申请实施例提供的上述非线性校正方法，通过在发射机中引入基于系数(也称参数)感知的数字预失真装置，通过生成回归矩阵、对回归矩阵进行正交化处理、生成正交基函数、获取输出信号、根据生成正交基函数将输出信号与功放模型的参数相关联、对输出信号进行采样以实现对功放模型参数的提取实现对满采样情况下的功放输出的预测，进而根据实际需求对DPD参数进行训练，以提高数字预失真装置的非线性校正性能，解决发射机的非线性失真问题。Based on the above-mentioned nonlinear correction method provided by the embodiment of the present application, by introducing a digital pre-distortion device based on coefficient (also called parameter) perception in the transmitter, by generating a regression matrix, performing orthogonalization processing on the regression matrix, and generating an orthogonal The basis function, obtaining the output signal, correlating the output signal with the parameters of the power amplifier model according to the generated orthogonal basis function, sampling the output signal to realize the extraction of the parameters of the power amplifier model and realizing the prediction of the power amplifier output under the condition of full sampling, and then The DPD parameters are trained according to actual needs to improve the nonlinear correction performance of the digital predistortion device and solve the nonlinear distortion problem of the transmitter.
在一些实施例中，为了降低DPD参数的训练时间，本申请实施例提供的非线性校正方法中，还可以采用分频段的功率放大器前向建模方式。In some embodiments, in order to reduce the training time of the DPD parameters, in the non-linear correction method provided in the embodiment of the present application, a power amplifier forward modeling manner divided into frequency bands may also be used.
作为一种示例，可以采用包括图12所示积分ADC 930、乘法器970-1、乘法器970-2、乘法器970-3和带限滤波器970-4的辅助电路分频段提取功放模型参数。As an example, an auxiliary circuit including the integral ADC 930 shown in Figure 12, the multiplier 970-1, the multiplier 970-2, the multiplier 970-3 and the band-limiting filter 970-4 can be used to extract the power amplifier model parameters by frequency division .
示例性的，在本申请实施例中，可以对输出信号进行M次带限建模。示例性的，带限滤波器970-4可以根据预设频段参数过滤信号。例如，预设频段参数包括带限滤波器970-4的带宽。例如，带限滤波器970-4的带宽如fs/M，是指将满采样带宽fs分为M段。假设M＝5，如图13所示，带限滤波器的带宽为fs/5。其中，图13所示f1＝f2＝f3＝f4＝f5＝fs/5。Exemplarily, in the embodiment of the present application, M times of band-limited modeling may be performed on the output signal. Exemplarily, the band-limit filter 970-4 can filter signals according to preset frequency band parameters. For example, the preset frequency band parameters include the bandwidth of the band-limiting filter 970-4. For example, the bandwidth of the band-limiting filter 970-4 is fs/M, which means that the full sampling bandwidth fs is divided into M segments. Assuming M=5, as shown in Figure 13, the bandwidth of the band-limited filter is fs/5. Wherein, f1=f2=f3=f4=f5=fs/5 shown in FIG. 13 .
记带限滤波器970-4的传递函为BL()，那么频段m的信号y m和回归矩阵
Figure PCTCN2022141085-appb-000025
的第k列基函数满足： Note that the transfer function of the band-limited filter 970-4 is BL(), then the signal y m and the regression matrix of the frequency band m
Figure PCTCN2022141085-appb-000025
The k-th column basis function of satisfies:
Figure PCTCN2022141085-appb-000026
Figure PCTCN2022141085-appb-000026
Figure PCTCN2022141085-appb-000027
Figure PCTCN2022141085-appb-000027
其中，
Figure PCTCN2022141085-appb-000028
对应回归矩阵
Figure PCTCN2022141085-appb-000029
进行正交变换后可以得到正交回归矩阵Ψ m： in,
Figure PCTCN2022141085-appb-000028
Corresponding regression matrix
Figure PCTCN2022141085-appb-000029
Orthogonal regression matrix Ψ m can be obtained after orthogonal transformation:
Figure PCTCN2022141085-appb-000030
Figure PCTCN2022141085-appb-000030
进一步的，正交回归矩阵Ψ m进行如下公式5所示特征值分解后，可以得到U m和Σ m： Furthermore, U m and Σ m can be obtained after the orthogonal regression matrix Ψ m undergoes eigenvalue decomposition as shown in the following formula 5:
Figure PCTCN2022141085-appb-000031
Figure PCTCN2022141085-appb-000031
上述公式5中，Σ m为频段m对应的特征值矩阵，Σ m＝diag(λ m,1,…,λ m,k,…,λ m,K)。K为DPD模型的系数个数,K＝P×(M+1)。 In the above formula 5, Σ m is the eigenvalue matrix corresponding to the frequency band m, Σ m =diag(λ m,1 ,...,λ m,k ,...,λ m,K ). K is the coefficient number of DPD model, K=P×(M+1).
基于频段m对应的正交回归矩阵Ψ m，可以构建得到频段m的功放前向建模公式(如以下公式6)。 Based on the orthogonal regression matrix Ψ m corresponding to the frequency band m, a power amplifier forward modeling formula (such as the following formula 6) can be constructed to obtain the frequency band m.
y m＝Ψ mc m。    (公式6) y m =Ψ m c m . (Formula 6)
进一步的，基于上述频段m的功放前向建模公式(即公式6)，利用最小二乘法可以确定频段m的功放模型参数c m＝(Ψ m HΨ m) -1Ψ m Hy m。其中，c m＝[c m,1,…,c m,k,…,c m,K]。c m的实部c I,m,k和虚部c Q,m,k分别为： Further, based on the above-mentioned power amplifier forward modeling formula of frequency band m (ie formula 6), the power amplifier model parameter c m =(Ψ m H Ψ m ) -1 Ψ m H y m of frequency band m can be determined by using the least square method. Wherein, c m =[c m,1 ,...,c m,k ,...,c m,K ]. The real part c I, m, k and imaginary part c Q, m, k of c m are:
Figure PCTCN2022141085-appb-000032
Figure PCTCN2022141085-appb-000032
Figure PCTCN2022141085-appb-000033
Figure PCTCN2022141085-appb-000033
进一步的，基函数生成模块900基于频段m的功放前向建模公式可以生成频段m的基函数矩阵z m(n)。z m(n)包括I路z I,m(n)和Q路z Q,m(n)。DAC 920-2对z I,m(n)和z Q,m(n)进行数 模转换，可以输出z m(t)。其中，z m(t)包括实部z I,m(t)和虚部z Q,m(t)。其中： Further, the basis function generating module 900 can generate the basis function matrix z m (n) of the frequency band m based on the power amplifier forward modeling formula of the frequency band m. z m (n) includes I-way z I,m (n) and Q-way z Q,m (n). DAC 920-2 performs digital-to-analog conversion on z I,m (n) and z Q,m (n), and can output z m (t). Wherein, z m (t) includes real part z I,m (t) and imaginary part z Q,m (t). in:
Figure PCTCN2022141085-appb-000034
Figure PCTCN2022141085-appb-000034
Figure PCTCN2022141085-appb-000035
Figure PCTCN2022141085-appb-000035
以下将结合图12，对本申请实施例提供的另一种非线性校正方法进行具体介绍。Another nonlinear correction method provided by the embodiment of the present application will be specifically introduced below with reference to FIG. 12 .
如图12中S1201所示，在S907之后，乘法器970-3对信号y 3(t)进行-mfs/M的频移，并将频移后的信号输入至带限滤波器970-4。 As shown in S1201 in FIG. 12 , after S907, the multiplier 970-3 performs a frequency shift of -mfs/M on the signal y 3 (t), and inputs the frequency-shifted signal to the band-limiting filter 970-4.
进一步的，如图12中的S1202所示，带限滤波器970-4根据预设频段设置参数过滤信号。Further, as shown in S1202 in FIG. 12 , the band-limiting filter 970-4 filters signals according to preset frequency band setting parameters.
以对频段m的信号进行处理为例，如图12所示，带限滤波器的输出包括I路信号y I,m(t)和Q路信号y Q,m(t)。 Taking the signal processing of the frequency band m as an example, as shown in FIG. 12 , the output of the band-limiting filter includes the I-channel signal y I,m (t) and the Q-channel signal y Q,m (t).
进一步的，如图12中的S1203所示，乘法器970-1将z I,m(t)与QDMod 950的输出信号y I,m(t)相乘；乘法器970-2将z Q,m(t)与QDMod 950的输出信号y Q,m(t)相乘。 Further, as shown in S1203 in FIG. 12 , the multiplier 970-1 multiplies z I,m (t) with the output signal y I,m (t) of the QDMod 950; the multiplier 970-2 multiplies z Q, m (t) is multiplied by the output signal y Q,m (t) of QDMod 950 .
其中，经过乘法器970-1处理之后，乘法器970-1的输出信号为z I,m(t)y I,m(t)；经过乘法器970-2处理之后，乘法器970-2的输出信号为z Q,m(t)y Q,m(t)。其中，z I,m(t)y I,m(t)＝λ m,k -1ψ I,m,k(t)y I,m(t)，z Q,m(t)y Q,m(t)＝λ k,m -1ψ Q,m,k(t)y Q,m(t)。 Wherein, after being processed by the multiplier 970-1, the output signal of the multiplier 970-1 is z I, m (t) y I, m (t); after being processed by the multiplier 970-2, the output signal of the multiplier 970-2 The output signal is z Q,m (t)y Q,m (t). Among them, z I,m (t)y I,m (t)=λ m,k -1 ψ I,m,k (t)y I,m (t), z Q,m (t)y Q, m (t) = λ k,m −1 ψ Q,m,k (t)y Q,m (t).
进一步的，如图12中的S1204所示，积分ADC 930可以根据实际需求，基于频段m的时域基函数矩阵z m(t)，按照预设周期对乘法器970-1和乘法器970-2的输出信号进行积分，以提取得到频段m的功放模型参数c I,m,k和/或c Q,m,k。 Further, as shown in S1204 in FIG. 12 , the integrating ADC 930 can perform multiplier 970-1 and multiplier 970- 2 to extract the power amplifier model parameters c I,m,k and/or c Q,m,k of the frequency band m.
例如，当[2(m-1)K+2k-2]T int≤t＜[2(m-1)K+2k-1]T int时，采样以获取频段m的功放模型参数c I,m,k，当[2(m-1)K+2k-1]T int≤t＜[2(m-1)K+2k]T int时，采样以获取频段m的功放模型参数c Q,m,k。关于上述S1101-S1104的具体过程，可以参考图14。 For example, when [2(m-1)K+2k-2]T int ≤t<[2(m-1)K+2k-1]T int , sample to obtain the power amplifier model parameter c I of frequency band m, m,k , when [2(m-1)K+2k-1]T int ≤t<[2(m-1)K+2k]T int , sample to obtain the power amplifier model parameter c Q of frequency band m, m,k . For the specific process of S1101-S1104 above, refer to FIG. 14 .
在获取频段m的功放模型参数之后，进一步的，如图12所示，本申请实施例提供的非线性校正方法可以估计满采样情况下频段m的功放输出，进而根据估计的满采样情况下频段m的功放输出训练DPD参数。例如，在本申请实施例中，可以基于传统的间接学习结构或者直接学习等结构训练DPD参数。其中，满采样情况下频段m的功放输出y m’＝Ψ mc m’。c m’为满采样情况下频段m的功放模型参数。 After obtaining the power amplifier model parameters of frequency band m, further, as shown in Figure 12, the nonlinear correction method provided by the embodiment of the present application can estimate the power amplifier output of frequency band m in the case of full sampling, and then according to the estimated full sampling of the frequency band The power amplifier output of m trains the DPD parameters. For example, in the embodiment of the present application, DPD parameters may be trained based on traditional indirect learning structures or direct learning structures. Wherein, the power amplifier output y m '=Ψ m c m ' of the frequency band m under the condition of full sampling. c m ' is the power amplifier model parameter of frequency band m in the case of full sampling.
或者，在获取频段m的功放模型参数之后，进一步的，本申请实施例提供的非线性校正方法可以估计满采样情况下频段m的功放输出。对于每一个频段，均可参考对频段m的处理方法。理想情况下，多个频段的功放输出通过M倍上采样和-mfs/M的频移后进行叠加，即可获取满采样情况下的功放输出，进而训练DPD参数。例如，在本申请实施例中，可以基于传统的间接学习结构或者直接学习等结构训练DPD参数。Alternatively, after acquiring the power amplifier model parameters of the frequency band m, further, the non-linear correction method provided in the embodiment of the present application may estimate the power amplifier output of the frequency band m in the case of full sampling. For each frequency band, refer to the processing method for frequency band m. Ideally, the power amplifier output of multiple frequency bands is superimposed after M times upsampling and -mfs/M frequency shift, and the power amplifier output under the full sampling condition can be obtained, and then the DPD parameters can be trained. For example, in the embodiment of the present application, DPD parameters may be trained based on traditional indirect learning structures or direct learning structures.
在本申请实施例中，通过将满采样带宽fs分为M段，可以将积分DAC 930的带宽降低M倍，从而允许使用低速ADC替代高速ADC，以降低功放模型参数提取的成本。In the embodiment of the present application, by dividing the full sampling bandwidth fs into M segments, the bandwidth of the integral DAC 930 can be reduced by M times, thereby allowing the use of low-speed ADCs instead of high-speed ADCs to reduce the cost of power amplifier model parameter extraction.
另外，由于c m’的维度均为K×1的列向量，特别地，由于对不同的频段进行前向建模，允许采用不同的基函数，即K可表示为与m相关的量，即K(m)，例如带内的频段对应的系数个数如K(0)可以较大，带外频段特别是频谱边缘的频段对应的系数个数如K(M/2)可以较小，从而可以灵活选择功放模型参数，降低DPD参数训练时间。 In addition, since the dimensions of c m ' are all K×1 column vectors, in particular, due to the forward modeling of different frequency bands, different basis functions are allowed, that is, K can be expressed as a quantity related to m, namely K(m), for example, the number of coefficients corresponding to the in-band frequency band such as K(0) can be large, and the number of coefficients corresponding to the out-of-band frequency band, especially the frequency band at the edge of the spectrum, such as K(M/2) can be small, so that The parameters of the power amplifier model can be flexibly selected to reduce the training time of DPD parameters.
可以理解本申请实施例提供的非线性校正方法既可以基于带限滤波器实现，也可以兼容 非带限方案。相比于非带限的非线性校正方法，带限非线性校正方法可以降低数字采样率，但是M倍的采样时间。为了可以综合考虑采样率和采样时间，本申请实施例可以引入时分的DAC机制。示例性的，在数字预失真装置刚上电时，可以选择采用图9所示方法进行非线性校正；在数字预失真装置性能稳定时，选择采用稳定状态下的DPD参数进行非线性校正。It can be understood that the nonlinear correction method provided by the embodiment of the present application can be implemented based on a band-limited filter, or can be compatible with a non-band-limited solution. Compared with the non-band-limited nonlinear correction method, the band-limited nonlinear correction method can reduce the digital sampling rate, but the sampling time is M times. In order to comprehensively consider the sampling rate and sampling time, the embodiment of the present application may introduce a time-division DAC mechanism. Exemplarily, when the digital predistortion device is powered on, the method shown in FIG. 9 can be selected to perform nonlinear correction; when the performance of the digital predistortion device is stable, DPD parameters in a stable state can be selected to perform nonlinear correction.
作为一种示例，上述时分的DAC机制可以通过时分开关(如信号选择时分开关)来实现。As an example, the above time-division DAC mechanism may be implemented by a time-division switch (such as a signal selection time-division switch).
请参考图15，图15示出了另一种数字预失真装置的结构示意图。如图15所示，数字预失真装置包括时分开关1501和DAC 1502。其中，时分开关1501可以工作在工作状态1或者工作状态2。Please refer to FIG. 15 , which shows a schematic structural diagram of another digital predistortion device. As shown in FIG. 15 , the digital predistortion device includes a time division switch 1501 and a DAC 1502. Wherein, the time division switch 1501 can work in working state 1 or working state 2.
当时分开关1501工作在工作状态1时，DAC 1502的输入为DPA 910的输出。DAC 1502可以用于对x I'(n)和x Q'(n)进行数模转换，输出x I(t)和x Q(t)。 When the time-division switch 1501 is working in the working state 1, the input of the DAC 1502 is the output of the DPA 910 . The DAC 1502 can be used to perform digital-to-analog conversion on x I '(n) and x Q '(n), and output x I (t) and x Q (t).
当时分开关1501工作在工作状态2时，DAC 1502的输入还可以包括基函数生成模块900的输出。DAC 1502可以用于对x I'(n)和x Q'(n)进行数模转换，输出x I(t)和x Q(t)；以及，对z I(n)和z Q(n)进行数模转换，输出z I(t)和z Q(t)。 When the time-division switch 1501 is working in the working state 2, the input of the DAC 1502 may also include the output of the basis function generation module 900 . The DAC 1502 can be used for digital-to-analog conversion of x I '(n) and x Q '(n), outputting x I (t) and x Q (t); and, for z I (n) and z Q (n ) for digital-to-analog conversion, and output z I (t) and z Q (t).
如图15所示，基于时分开关的非线性校正方案还可以使得数字预失真装置减少一个ADC，因此基于时分开关的非线性校正方案还可以降低非线性校正的成本。As shown in FIG. 15 , the non-linear correction solution based on the time-division switch can also reduce the digital pre-distortion device by one ADC, so the non-linear correction solution based on the time-division switch can also reduce the cost of nonlinear correction.
在一些实施例中，为了保证乘法器970-1和乘法器970-2同步处理处理I路信号和Q路信号，如图16所示，本申请实施例还可以引入延时器1600。其中，延时器1600可以是可调延时器，以便可以根据实际需求调整延时器的延时参数(如延时时长、精度等)。示例性的，延时器的精度与由当前信号的符号率Fs相关，例如延时器的精度为1/(5*Fs)。In some embodiments, in order to ensure that the multiplier 970-1 and the multiplier 970-2 process the I-channel signal and the Q-channel signal synchronously, as shown in FIG. 16 , a delayer 1600 may also be introduced in this embodiment of the present application. Wherein, the delayer 1600 can be an adjustable delayer, so that the delay parameters (such as delay time, precision, etc.) of the delayer can be adjusted according to actual needs. Exemplarily, the precision of the delayer is related to the symbol rate Fs of the current signal, for example, the precision of the delayer is 1/(5*Fs).
需要说明的是，图15仅作为一种包括有时分开关的数字预失真装置结构示例，图16仅作为一种包括延时器的数字预失真装置结构示例，本申请实施例提供的基于时分开关的非线性校正方案还可以适应于其他结构，例如图12所示结构的数字预失真装置。本申请实施例提供的基于延时器的非线性校正方案还可以适应于其他结构，例如图9或图12所示结构的数字预失真装置。It should be noted that Fig. 15 is only an example of the structure of a digital predistortion device including a time-division switch, and Fig. 16 is only an example of the structure of a digital pre-distortion device including a delay device. The non-linear correction scheme of can also be adapted to other structures, such as the digital predistortion device with the structure shown in FIG. 12 . The delayer-based nonlinear correction solution provided in the embodiment of the present application may also be applicable to other structures, for example, the digital predistortion device with the structure shown in FIG. 9 or FIG. 12 .
应理解，本申请实施例的各个方案可以进行合理的组合使用，并且实施例中出现的各个术语的解释或说明可以在各个实施例中互相参考或解释，对此不作限定。It should be understood that various schemes of the embodiments of the present application can be used in a reasonable combination, and the explanations or descriptions of various terms appearing in the embodiments can be referred to or interpreted in each embodiment, which is not limited.
还应理解，在本申请的各种实施例中，上述各过程的序号的大小并不意味着执行顺序的先后，各过程的执行顺序应以其功能和内在逻辑确定，而不应对本申请实施例的实施过程构成任何限定。It should also be understood that in various embodiments of the present application, the serial numbers of the above-mentioned processes do not mean the order of execution, and the order of execution of the processes should be determined by their functions and internal logic, and should not be implemented in this application. The implementation of the examples constitutes no limitation.
可以理解的是，非线性校正装置为了实现上述任一个实施例的功能，其包含了执行各个功能相应的硬件结构和/或软件模块。本领域技术人员应该很容易意识到，结合本文中所公开的实施例描述的各示例的单元及算法步骤，本申请能够以硬件或硬件和计算机软件的结合形式来实现。某个功能究竟以硬件还是计算机软件驱动硬件的方式来执行，取决于技术方案的特定应用和设计约束条件。专业技术人员可以对每个特定的应用来使用不同方法来实现所描述的功能，但是这种实现不应认为超出本申请的范围。It can be understood that, in order to realize the functions of any one of the above embodiments, the non-linear correction device includes corresponding hardware structures and/or software modules for performing various functions. Those skilled in the art should easily realize that the present application can be implemented in the form of hardware or a combination of hardware and computer software in combination with the units and algorithm steps of each example described in the embodiments disclosed herein. Whether a certain function is executed by hardware or computer software drives hardware depends on the specific application and design constraints of the technical solution. Skilled artisans may use different methods to implement the described functions for each specific application, but such implementation should not be regarded as exceeding the scope of the present application.
本申请实施例可以对非线性校正装置进行功能模块的划分，例如，可以对应各个功能划分各个功能模块，也可以将两个或两个以上的功能集成在一个处理模块中。上述集成的模块既可以采用硬件的形式实现，也可以采用软件功能模块的形式实现。需要说明的是，本申请实施例中对模块的划分是示意性的，仅仅为一种逻辑功能划分，实际实现时可以有另外的划分方式。In this embodiment of the present application, the nonlinear correction device can be divided into functional modules. For example, each functional module can be divided corresponding to each function, or two or more functions can be integrated into one processing module. The above-mentioned integrated modules can be implemented in the form of hardware or in the form of software function modules. It should be noted that the division of modules in the embodiment of the present application is schematic, and is only a logical function division, and there may be other division methods in actual implementation.
应理解，非线性校正装置中的各个模块可以通过软件和/或硬件形式实现，对此不作具体 限定。换言之，电子设备是以功能模块的形式来呈现。这里的“模块”可以指特定应用集成电路ASIC、电路、执行一个或多个软件或固件程序的处理器和存储器、集成逻辑电路，和/或其它可以提供上述功能的器件。It should be understood that each module in the non-linear correction device may be implemented in the form of software and/or hardware, which is not specifically limited. In other words, electronic equipment is presented in the form of functional modules. The "module" here may refer to an application-specific integrated circuit ASIC, a circuit, a processor and memory executing one or more software or firmware programs, an integrated logic circuit, and/or other devices that can provide the above-mentioned functions.
在一种可选的方式中，当使用软件实现数据传输时，可以全部或部分地以计算机程序产品的形式实现。所述计算机程序产品包括一个或多个计算机指令。在计算机上加载和执行所述计算机程序指令时，全部或部分地实现本申请实施例所述的流程或功能。所述计算机可以是通用计算机、专用计算机、计算机网络、或者其它可编程装置。所述计算机指令可以存储在计算机可读存储介质中，或者从一个计算机可读存储介质向另一个计算机可读存储介质传输，例如，所述计算机指令可以从一个网站站点、计算机、服务器或数据中心通过有线(例如同轴电缆、光纤、数字用户线((digital subscriber line，DSL))或无线(例如红外、无线、微波等)方式向另一个网站站点、计算机、服务器或数据中心进行传输。所述计算机可读存储介质可以是计算机能够存取的任何可用介质或者是包含一个或多个可用介质集成的服务器、数据中心等数据存储设备。所述可用介质可以是磁性介质，(例如软盘、硬盘、磁带)、光介质(例如数字化视频光盘(digital video disk，DVD))、或者半导体介质(例如固态硬盘solid state disk(SSD))等。In an optional manner, when software is used to implement data transmission, it may be implemented in whole or in part in the form of computer program products. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on the computer, the processes or functions described in the embodiments of the present application are realized in whole or in part. The computer can be a general purpose computer, a special purpose computer, a computer network, or other programmable devices. The computer instructions may be stored in or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from a website, computer, server or data center Transmission to another website site, computer, server or data center by wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or a data center that includes one or more available mediums. The available medium can be a magnetic medium, (such as a floppy disk, a hard disk, etc. , tape), optical media (such as digital video disk (digital video disk, DVD)), or semiconductor media (such as solid state disk (SSD)), etc.
结合本申请实施例所描述的方法或者算法的步骤可以硬件的方式来实现，也可以是由处理器执行软件指令的方式来实现。软件指令可以由相应的软件模块组成，软件模块可以被存放于RAM存储器、闪存、ROM存储器、EPROM存储器、EEPROM存储器、寄存器、硬盘、移动硬盘、CD-ROM或者本领域熟知的任何其它形式的存储介质中。一种示例性的存储介质耦合至处理器，从而使处理器能够从该存储介质读取信息，且可向该存储介质写入信息。当然，存储介质也可以是处理器的组成部分。处理器和存储介质可以位于ASIC中。另外，该ASIC可以位于电子设备中。当然，处理器和存储介质也可以作为分立组件存在于非线性校正装置中。The steps of the methods or algorithms described in conjunction with the embodiments of the present application may be implemented in hardware, or may be implemented in a manner in which a processor executes software instructions. The software instructions can be composed of corresponding software modules, and the software modules can be stored in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, mobile hard disk, CD-ROM or any other form of storage known in the art medium. An exemplary storage medium is coupled to the processor such the processor can read information from, and write information to, the storage medium. Of course, the storage medium may also be a component of the processor. The processor and storage medium can be located in the ASIC. Alternatively, the ASIC may be located in the electronic device. Of course, the processor and the storage medium can also exist in the nonlinear correction device as discrete components.
通过以上的实施方式的描述，所属领域的技术人员可以清楚地了解到，为描述的方便和简洁，仅以上述各功能模块的划分进行举例说明，实际应用中，可以根据需要而将上述功能分配由不同的功能模块完成，即将装置的内部结构划分成不同的功能模块，以完成以上描述的全部或者部分功能。Through the description of the above embodiments, those skilled in the art can clearly understand that for the convenience and brevity of the description, only the division of the above-mentioned functional modules is used as an example for illustration. In practical applications, the above-mentioned functions can be allocated according to needs It is completed by different functional modules, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above.

Claims (25)

  1. 一种非线性校正方法，其特征在于，所述方法包括：A nonlinear correction method, characterized in that the method comprises:
    对第一信号进行预设处理，得到第二信号；performing preset processing on the first signal to obtain a second signal;
    基于所述第一信号生成正交回归矩阵；generating an orthogonal regression matrix based on the first signal;
    根据所述正交回归矩阵，构建得到功率放大器PA前向建模公式；According to the orthogonal regression matrix, construct and obtain the power amplifier PA forward modeling formula;
    根据所述PA前向建模公式生成正交基函数；Generate orthogonal basis functions according to the PA forward modeling formula;
    通过对所述正交基函数和所述第二信号的乘积进行积分，获取PA模型参数；obtaining PA model parameters by integrating the product of the orthogonal basis function and the second signal;
    根据所述PA模型参数调整非线性校正参数。Adjusting nonlinear correction parameters according to the PA model parameters.
  2. 根据权利要求1所述的方法，其特征在于，所述非线性校正参数是数字预失真DPD参数。The method according to claim 1, wherein the nonlinear correction parameters are digital predistortion (DPD) parameters.
  3. 根据权利要求1或2所述的方法，其特征在于，所述通过对所述正交基函数和所述第二信号的乘积进行积分，获取PA模型参数，包括：The method according to claim 1 or 2, wherein said obtaining PA model parameters by integrating the product of said orthogonal basis function and said second signal comprises:
    将所述正交基函数与所述第二信号的I路信号和Q路信号分别相乘，获取I路乘积和Q路乘积；multiplying the orthogonal basis function by the I-channel signal and the Q-channel signal of the second signal, respectively, to obtain the I-channel product and the Q-channel product;
    根据预设周期对所述I路乘积和Q路乘积进行积分，以获取所述PA模型参数。Integrating the I-way product and the Q-way product according to a preset period to obtain the PA model parameters.
  4. 根据权利要求3所述的方法，其特征在于，所述预设周期为T int，所述T int满足： The method according to claim 3, wherein the preset period is T int , and the T int satisfies:
    T int≥N intTs T int ≥ N int Ts
    其中，所述N int为预设值，所述N int与所述PA模型参数的个数和/或发射机的性能相关，所述Ts为满采样情况下的采样周期。 Wherein, the N int is a preset value, the N int is related to the number of the PA model parameters and/or the performance of the transmitter, and the Ts is a sampling period under full sampling.
  5. 根据权利要求3或4所述的方法，其特征在于，所述根据预设周期对所述I路乘积和Q路乘积进行积分，以获取所述PA模型参数，包括：The method according to claim 3 or 4, wherein the integration of the I-way product and the Q-way product according to a preset period to obtain the PA model parameters includes:
    在第一时刻对所述I路乘积和Q路乘积进行积分，获取第一PA模型参数，所述第一时刻满足第一条件；Integrating the I-way product and the Q-way product at a first moment to obtain a first PA model parameter, the first condition is satisfied at the first moment;
    在第二时刻对所述I路乘积和Q路乘积进行积分，获取第二PA模型参数，所述第二时刻满足第二条件。Integrating the I-way product and the Q-way product at a second moment to obtain a second PA model parameter, the second condition is met at the second moment.
  6. 根据权利要求1-5中任一项所述的方法，其特征在于，所述第一信号是输入信号中预设频段的信号。The method according to any one of claims 1-5, wherein the first signal is a signal of a preset frequency band in the input signal.
  7. 根据权利要求6所述的方法，其特征在于，所述方法还包括：The method according to claim 6, further comprising:
    对所述输入信号中所有频段的信号，采用与所述第一信号相同的方法进行非线性校正参数调整。For signals of all frequency bands in the input signal, the non-linear correction parameter adjustment is performed using the same method as that of the first signal.
  8. 根据权利要求1-7中任一项所述的方法，其特征在于，所述方法还包括：The method according to any one of claims 1-7, further comprising:
    在所述非线性校正参数稳定时，根据调整后的所述非线性校正参数进行信号发射前的信号非线性校正。When the nonlinear correction parameter is stable, perform signal nonlinear correction before signal transmission according to the adjusted nonlinear correction parameter.
  9. 根据权利要求3-8中任一项所述的方法，其特征在于，所述将所述正交基函数与所述第二信号的I路信号和Q路信号分别相乘，获取I路乘积和Q路乘积，包括：The method according to any one of claims 3-8, wherein said multiplying said orthogonal basis function with the I-way signal and the Q-way signal of said second signal respectively to obtain the I-way product And the Q-way product, including:
    同步将所述正交基函数与所述第二信号的I路信号和Q路信号分别相乘，获取所述I路乘积和所述Q路乘积。synchronously multiplying the orthogonal basis function by the I-channel signal and the Q-channel signal of the second signal, to obtain the I-channel product and the Q-channel product.
  10. 根据权利要求1-9中任一项所述的方法，其特征在于，所述基于所述第一信号生成正交回归矩阵，包括：The method according to any one of claims 1-9, wherein the generating an orthogonal regression matrix based on the first signal comprises:
    基于所述第一信号生成回归矩阵；generating a regression matrix based on the first signal;
    对所述回归矩阵进行正交变换，得到所述正交回归矩阵。Performing an orthogonal transformation on the regression matrix to obtain the orthogonal regression matrix.
  11. 根据权利要求1-10中任一项所述的方法，其特征在于，所述对第一信号进行预设处理，得到第二信号，包括：The method according to any one of claims 1-10, wherein said performing preset processing on the first signal to obtain the second signal comprises:
    对所述第一信号分别进行数字预失真、数模转换、正交调制以及功率放大后得到所述第二信号。The second signal is obtained after performing digital pre-distortion, digital-to-analog conversion, quadrature modulation, and power amplification on the first signal respectively.
  12. 一种非线性校正装置，其特征在于，所述装置包括：A nonlinear correction device, characterized in that the device comprises:
    发射模块，用于对第一信号进行预设处理，得到第二信号；A transmitting module, configured to perform preset processing on the first signal to obtain the second signal;
    基函数生成模块，用于基于所述第一信号生成正交回归矩阵；根据所述正交回归矩阵，构建得到功率放大器PA前向建模公式；以及，根据所述PA前向建模公式生成正交基函数；A basis function generation module, configured to generate an orthogonal regression matrix based on the first signal; according to the orthogonal regression matrix, construct a power amplifier PA forward modeling formula; and generate according to the PA forward modeling formula Orthogonal basis functions;
    积分模拟数字转换模块，用于通过对所述正交基函数和所述第二信号的乘积进行积分，获取PA模型参数；An integral analog-to-digital conversion module, configured to obtain PA model parameters by integrating the product of the orthogonal basis function and the second signal;
    预失真模块，用于根据所述PA模型参数调整非线性校正参数。A pre-distortion module, configured to adjust nonlinear correction parameters according to the PA model parameters.
  13. 根据权利要求12所述的装置，其特征在于，所述非线性校正参数是数字预失真DPD参数。The device according to claim 12, wherein the nonlinear correction parameters are digital predistortion (DPD) parameters.
  14. 根据权利要求12或13所述的装置，其特征在于，所述积分模拟数字转换模块具体用于：The device according to claim 12 or 13, wherein the integral analog-to-digital conversion module is specifically used for:
    将所述正交基函数与所述第二信号的I路信号和Q路信号分别相乘，获取I路乘积和Q路乘积；以及，Multiplying the orthogonal basis function by the I-way signal and the Q-way signal of the second signal, respectively, to obtain the I-way product and the Q-way product; and,
    根据预设周期对所述I路乘积和Q路乘积进行积分，以获取所述PA模型参数。Integrating the I-way product and the Q-way product according to a preset period to obtain the PA model parameters.
  15. 根据权利要求14所述的装置，其特征在于，所述预设周期为T int，所述T int满足： The device according to claim 14, wherein the preset period is T int , and the T int satisfies:
    T int≥N intTs T int ≥ N int Ts
    其中，所述N int为预设值，所述N int与所述PA模型参数的个数和/或发射机的性能相关，所述Ts为满采样情况下的采样周期。 Wherein, the N int is a preset value, the N int is related to the number of the PA model parameters and/or the performance of the transmitter, and the Ts is a sampling period under full sampling.
  16. 根据权利要求14或15所述的装置，其特征在于，所述积分模拟数字转换模块具体用于：The device according to claim 14 or 15, wherein the integral analog-to-digital conversion module is specifically used for:
    在第一时刻对所述I路乘积和Q路乘积进行积分，获取第一PA模型参数，所述第一时刻满足第一条件；Integrating the I-way product and the Q-way product at a first moment to obtain a first PA model parameter, the first condition is satisfied at the first moment;
    在第二时刻对所述I路乘积和Q路乘积进行积分，获取第二PA模型参数，所述第二时刻满足第二条件。Integrating the I-way product and the Q-way product at a second moment to obtain a second PA model parameter, the second condition is satisfied at the second moment.
  17. 根据权利要求12-16中任一项所述的装置，其特征在于，所述第一信号是输入信号中预设频段的信号。The device according to any one of claims 12-16, wherein the first signal is a signal of a preset frequency band in the input signal.
  18. 根据权利要求17所述的装置，其特征在于，所述积分模拟数字转换模块还用于：The device according to claim 17, wherein the integral analog-to-digital conversion module is also used for:
    对所述输入信号中所有频段的信号，采用与所述第一信号相同的方法进行非线性校正参数调整。For signals of all frequency bands in the input signal, the non-linear correction parameter adjustment is performed using the same method as that of the first signal.
  19. 根据权利要求12-18中任一项所述的装置，其特征在于，在所述非线性校正参数稳定时，所述预失真模块还用于：The device according to any one of claims 12-18, wherein when the nonlinear correction parameters are stable, the pre-distortion module is further configured to:
    根据调整后的所述非线性校正参数进行信号发射前的信号非线性校正。Perform signal nonlinear correction before signal transmission according to the adjusted nonlinear correction parameters.
  20. 根据权利要求16-19中任一项所述的装置，其特征在于，所述积分模拟数字转换模块具体用于：The device according to any one of claims 16-19, wherein the integral analog-to-digital conversion module is specifically used for:
    同步将所述正交基函数与所述第二信号的I路信号和Q路信号分别相乘，获取所述I路乘积和所述Q路乘积。synchronously multiplying the orthogonal basis function by the I-channel signal and the Q-channel signal of the second signal, to obtain the I-channel product and the Q-channel product.
  21. 根据权利要求12-20中任一项所述的装置，其特征在于，所述基函数生成模块，具 体用于：The device according to any one of claims 12-20, wherein the basis function generation module is specifically used for:
    基于所述第一信号生成回归矩阵；generating a regression matrix based on the first signal;
    对所述回归矩阵进行正交变换，得到所述正交回归矩阵。Performing an orthogonal transformation on the regression matrix to obtain the orthogonal regression matrix.
  22. 根据权利要求12-21中任一项所述的装置，其特征在于，所述发射模块具体用于：The device according to any one of claims 12-21, wherein the transmitting module is specifically used for:
    对所述第一信号分别进行数字预失真、数模转换、正交调制以及功率放大后得到所述第二信号。The second signal is obtained after performing digital pre-distortion, digital-to-analog conversion, quadrature modulation, and power amplification on the first signal respectively.
  23. 一种计算机可读存储介质，其特征在于，所述计算机可读存储介质上存储有计算机程序代码，所述计算机程序代码被处理电路执行时实现如权利要求1-11任一项所述的方法。A computer-readable storage medium, characterized in that computer program code is stored on the computer-readable storage medium, and when the computer program code is executed by a processing circuit, the method according to any one of claims 1-11 is realized .
  24. 一种芯片***，其特征在于，所述芯片***包括处理电路、存储介质，所述存储介质中存储有计算机程序代码；所述计算机程序代码被所述处理电路执行时实现如权利要求1-11中任一项所述的方法。A chip system, characterized in that the chip system includes a processing circuit and a storage medium, and computer program codes are stored in the storage medium; when the computer program codes are executed by the processing circuit, claims 1-11 are realized. any one of the methods described.
  25. 一种计算机程序产品，其特征在于，所述计算机程序产品用于在计算机上运行，以实现如权利要求1-11中任一项所述的方法。A computer program product, characterized in that the computer program product is used to run on a computer to implement the method according to any one of claims 1-11.
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