WO2023199462A1 - Wireless communication method, wireless communication system, transmission device, and reception device - Google Patents

Wireless communication method, wireless communication system, transmission device, and reception device Download PDF

Info

Publication number
WO2023199462A1
WO2023199462A1 PCT/JP2022/017776 JP2022017776W WO2023199462A1 WO 2023199462 A1 WO2023199462 A1 WO 2023199462A1 JP 2022017776 W JP2022017776 W JP 2022017776W WO 2023199462 A1 WO2023199462 A1 WO 2023199462A1
Authority
WO
WIPO (PCT)
Prior art keywords
roll
unit
signal
oam
rate
Prior art date
Application number
PCT/JP2022/017776
Other languages
French (fr)
Japanese (ja)
Inventor
知哉 景山
斗煥 李
宏礼 芝
健 平賀
淳 増野
裕文 笹木
穂乃花 伊藤
康徳 八木
Original Assignee
日本電信電話株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 日本電信電話株式会社 filed Critical 日本電信電話株式会社
Priority to PCT/JP2022/017776 priority Critical patent/WO2023199462A1/en
Publication of WO2023199462A1 publication Critical patent/WO2023199462A1/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J99/00—Subject matter not provided for in other groups of this subclass

Definitions

  • the present invention relates to a wireless communication method, a wireless communication system, a transmitter, and a receiver.
  • Non-Patent Document 1 In recent years, in order to improve communication capacity, studies are underway on spatial multiplexing transmission technology for wireless signals using orbital angular momentum (OAM) (see, for example, Non-Patent Document 1).
  • OAM orbital angular momentum
  • an electromagnetic wave having OAM equal phase planes are distributed in a spiral shape along the propagation direction with the propagation axis as the center.
  • Electromagnetic waves having different OAM modes and propagating in the same direction have spatial phase distributions that are orthogonal in the rotation axis direction. Therefore, it is possible to spatially multiplex the signals by separating the signals of each OAM mode modulated with different signal sequences in the receiving device.
  • This OAM multiplex transmission can be realized by generating and multiplexing multiple OAM modes using a circular array antenna (UCA) in which multiple antenna elements are arranged in a circle at regular intervals (for example, , Non-Patent Document 2).
  • UCA circular array antenna
  • DFT discrete Fourier transform
  • IDFT inverse discrete Fourier transform
  • a transmitting device OAM multiplexes multiple signals and transmits them. Therefore, when the signal point phases of the modulated signals of each mode are combined in the same phase, the peak-to-average power ratio (PAPR) of the transmission signal increases.
  • PAPR peak-to-average power ratio
  • a signal with a high PAPR is amplified by a power amplifier, it is necessary to provide a large back-off of input power, so a reduction in output power becomes a problem. As a result, the received SNR decreases and signal quality deteriorates.
  • an object of the present invention is to provide a wireless communication method, a wireless communication system, a transmitter, and a receiver that can improve the data rate while reducing PAPR.
  • a transmitting device determines a roll-off rate based on at least part of a parameter representing a modulation method of an OAM multiplexed signal obtained by multiplexing signals using each OAM (Orbital Angular Momentum) mode.
  • a determining step in which the transmitting device applies roll-off filter processing to a transmission signal using the roll-off rate determined in the determining step;
  • the method includes a notification step of notifying the transmitting device of the result, and a changing step of the transmitting device changing the roll-off rate based on the estimation result notified from the receiving device.
  • One aspect of the present invention is a wireless communication system including a transmitting device and a receiving device, wherein the transmitting device expresses a modulation method of an OAM multiplexed signal in which signals using each OAM (Orbital Angular Momentum) mode are multiplexed.
  • OAM Organic Angular Momentum
  • a determining unit that determines a roll-off rate based on at least a portion of a parameter
  • a filter applying unit that applies roll-off filter processing to a transmission signal using the roll-off rate determined by the determining unit; and the filter applying unit a transmitting unit that generates an OAM multiplex signal from the transmission signal subjected to the roll-off filter processing according to the modulation method and transmits the generated OAM multiplex signal; and a nonlinear distortion of the OAM multiplex signal in the receiving device.
  • the apparatus includes an estimating section that estimates nonlinear distortion of the OAM multiplexed signal, and a notification section that notifies the transmitting device of the estimation result by the estimating section.
  • a transmitting device determines a roll-off rate and a symbol rate based on at least a part of parameters representing a modulation method of an OAM multiplexed signal obtained by multiplexing signals using each OAM (Orbital Angular Momentum) mode.
  • a transmitting unit that generates an OAM multiplexed signal and transmits the generated OAM multiplexed signal, and a changing unit that changes the roll-off rate based on an estimation result of nonlinear distortion of the OAM multiplexed signal in a receiving device.
  • a receiving device includes a receiving unit that receives an OAM multiplexed signal in which signals using each OAM (Orbital Angular Momentum) mode are multiplexed from a transmitting device, and performs reception processing on the received OAM multiplexed signal; an estimating unit that estimates nonlinear distortion based on a difference between a mean square error of a high voltage signal point and a mean square error of a low voltage signal point in the constellation of the OAM multiplex signal received and processed by the receiving unit; a notification unit that notifies the transmitting device of the estimation result by the estimation unit, the receiving unit transmitting a transmission signal to which roll-off filter processing using a roll-off rate changed based on the estimation result is applied. receives an OAM multiplex signal generated from the transmitting device.
  • OAM Organic Angular Momentum
  • FIG. 6 is a diagram illustrating an example of UCA phase settings for generating an OAM mode signal.
  • 1 is a configuration diagram of a wireless communication system in an embodiment of the present invention. It is a diagram showing an example of the configuration of a transmitting device in the same embodiment.
  • FIG. 3 is a diagram illustrating an example of a connection configuration of an OAM mode generation device, an RF chain, and a UCA of a transmitting device in the same embodiment. It is a figure showing an example of functional composition of a transmission control device in the same embodiment. It is a figure showing an example of functional composition of a transmission parameter decision device in the same embodiment.
  • FIG. 3 is a sequence diagram showing processing of the wireless communication system in the same embodiment.
  • FIG. 6 is a diagram illustrating an example of a reception constellation subjected to nonlinear distortion in the same embodiment.
  • FIG. 3 is a flow diagram showing an algorithm for estimating the presence or absence of nonlinear distortion from a received constellation in the same embodiment.
  • FIG. 3 is a flow diagram showing an algorithm for determining a roll-off rate and a symbol rate in the same embodiment. It is a diagram showing the hardware configuration of a transmitting device and a receiving device in the same embodiment.
  • the present embodiment relates to a technology for spatially multiplexing and transmitting wireless signals using orbital angular momentum (OAM) of electromagnetic waves.
  • OFAM orbital angular momentum
  • the transmitting device of this embodiment includes an adaptive control section, a filter application section, a notification section, and a transmitting section.
  • the adaptive control section includes a determining section and a changing section.
  • the determining unit determines a roll-off rate of a band-limiting filter (roll-off filter) to be applied to the transmission signal of each OAM mode, based on the number of modes to be multiplexed.
  • the filter application unit performs filter processing to apply a band-limiting filter having the determined roll-off rate to the transmission signal of each OAM mode.
  • the notification unit notifies the receiving device of the roll-off rate used for filter processing.
  • the transmitter multiplexes the filtered transmission signals of each OAM mode and transmits the OAM multiplexed signals.
  • the receiving device of this embodiment includes a device for estimating nonlinear distortion of a received signal.
  • the receiving device notifies the transmitting device of information on the estimated nonlinear distortion.
  • the changing unit of the transmitting device changes the roll-off rate based on the nonlinear distortion information notified from the receiving device, and accordingly maximizes the symbol rate within a range where the bandwidth satisfies regulations.
  • PAPR is reduced by controlling the roll-off rate and symbol rate of the roll-off filter applied to the transmission signal in wireless communication using OAM based on the nonlinear distortion in the receiving device. , increasing data rate while reducing nonlinear distortion.
  • FIG. 1 is a diagram showing an example of UCA phase settings for generating an OAM mode signal.
  • FIGS. 1(a) to 1(e) respectively show phase settings of signals transmitted from each UCA in order for the transmitting device to generate signals of OAM modes 0 to 4.
  • the OAM mode is also simply referred to as a mode.
  • a circle placed on the dotted line circumference indicates each antenna element of the UCA. The figure shows an example in which there are eight antenna elements.
  • the transmitting device generates an OAM mode signal by giving a phase difference using a DFT transformation matrix to the signal supplied to each antenna element of the UCA. Near each circle representing an antenna element, the phase difference given to the signal transmitted from that antenna element is shown. Specifically, the phase difference of the OAM mode n signal supplied to each antenna element is set so that the phase is n rotations. For example, as shown in FIG. 1(c), when an OAM mode 2 signal is generated using an 8-element UCA, the phase difference given to each antenna element is 0 degrees, 90 degrees, 180 degrees, and 270 degrees in the clockwise direction. degrees, 0 degrees, 90 degrees, 180 degrees, and 270 degrees. Furthermore, by applying a phase difference to each antenna element in the opposite direction to OAM mode 2, an OAM mode-2 signal is generated.
  • the number of multiplexed modes can be up to the same number as the number of antenna elements, but may be less than the number of antenna elements.
  • the phase of each antenna element of the UCA included in the receiving device may be set to be in the opposite rotation direction to the phase of the transmitting device.
  • FIG. 2 is a configuration diagram of the wireless communication system 1 in the embodiment of the present invention.
  • the wireless communication system 1 includes a wireless transmission device 11 and a wireless transmission device 12.
  • the wireless transmission device 11 and the wireless transmission device 12 are installed facing each other.
  • the wireless transmission devices 11 and 12 are base stations that do not move.
  • such an assumption is just an example. That is, one or both of the wireless transmission devices 11 and 12 may move.
  • the wireless transmission device 11 and the wireless transmission device 12 each have a transmitting device 100 and a receiving device 200.
  • the transmitting device 100 and the receiving device 200 are wireless communication devices that perform wireless communication.
  • the transmitting device 100 has an OAM multiplex signal transmitting function.
  • Transmitting device 100 includes an OAM mode generating device and a UCA.
  • the transmitting device 100 transmits an OAM multiplexed signal in which signals of one or more different OAM modes are multiplexed from the UCA.
  • the receiving device 200 has an OAM multiplex signal receiving function.
  • Receiving device 200 includes an OAM mode separation device and a UCA.
  • Receiving device 200 receives, by UCA, an OAM multiplexed signal in which signals of one or more OAM modes transmitted from opposing transmitting device 100 are multiplexed, and separates the signals of each OAM mode from the received OAM multiplexed signal.
  • FIG. 3 is a diagram showing a configuration example of the transmitting device 100.
  • the transmission device 100 includes a nonlinear distortion acquisition device 110, a transmission control device 120, a signal processing device 130, a transmission parameter determination device 140, a transmission parameter notification device 150, and a roll-off filter application device. 160, an OAM mode generation device 170, an RF (Radio Frequency) chain 180, and a UCA 190.
  • a nonlinear distortion acquisition device 110 includes a transmission control device 120, a signal processing device 130, a transmission parameter determination device 140, a transmission parameter notification device 150, and a roll-off filter application device.
  • 160 an OAM mode generation device 170, an RF (Radio Frequency) chain 180, and a UCA 190.
  • RF Radio Frequency
  • the nonlinear distortion acquisition device 110 acquires the nonlinear distortion information notified from the receiving device 200.
  • the nonlinear distortion information indicates the presence or absence of nonlinear distortion in the received signal.
  • Nonlinear distortion acquisition device 110 transmits the acquired nonlinear distortion information to transmission parameter determination device 140 via transmission control device 120.
  • the transmission control device 120 specifies the values of parameters such as the number of mode multiplexing, the transmission OAM mode, the number of modulation levels, and the symbol rate.
  • the modulation method of the OAM multiplex signal is determined by the values of these parameters.
  • Transmission control device 120 notifies signal processing device 130, transmission parameter determination device 140, and OAM mode generation device 170 of the specified values of these parameters.
  • the signal processing device 130 generates a digital signal to be transmitted on a carrier wave based on the input data and the parameter values notified from the transmission control device 120.
  • the signal processing device 130 converts the generated digital signal into an analog signal.
  • the signal processing device 130 inputs the transmission signal converted into an analog signal to the roll-off filter application device 160.
  • the roll-off filter applying device 160 can perform processing on digital signals and can also perform processing on analog signals. When processing by the roll-off filter applying device 160 is performed by digital processing, the transmission signal is converted into an analog signal after applying the roll-off filter.
  • the transmission parameter determination device 140 determines the roll-off rate of the roll-off filter based on the transmission OAM mode and mode multiplexing number notified from the transmission control device 120.
  • the roll-off filter is used for filtering the transmission signal of each OAM mode. Further, the transmission parameter determining device 140 maximizes the symbol rate within a range that satisfies the signal bandwidth regulation according to the determined roll-off rate. Transmission parameter determination device 140 inputs information on the determined roll-off rate and symbol rate to transmission parameter notification device 150 and roll-off filter application device 160.
  • the transmission parameter notification device 150 converts the roll-off rate and symbol rate information input from the transmission parameter determination device 140 into a format suitable for notification to the reception device 200, and then notifies the reception device 200.
  • the receiving device 200 may perform the band limiting process using a roll-off filter using the roll-off rate notified from the transmission parameter notification device 150, or may perform band-limiting processing using a roll-off filter using a roll-off rate determined in advance. may also be used. Further, receiving device 200 may sample the received signal using the symbol rate notified from transmission parameter notification device 150, or may use a predetermined prescribed symbol rate. When receiving device 200 uses a specified roll-off rate and a specified symbol rate, transmitting device 100 may or may not include transmission parameter notification device 150.
  • the roll-off filter application device 160 converts the transmission signal input from the signal processing device 130 into a signal at the symbol rate notified from the transmission parameter determination device 140. Roll-off filter application device 160 applies roll-off filter processing to the converted signal using the roll-off rate notified from transmission parameter determination device 140. Roll-off filter application device 160 inputs the filtered signal to OAM mode generation device 170.
  • the OAM mode generation device 170 is an analog circuit or a digital signal processing device that provides a DFT transformation matrix. OAM mode generation device 170 generates a transmission signal in a mode specified by transmission control device 120 by adding a DFT transformation matrix to the signal input from roll-off filter application device 160.
  • the OAM mode generation device 170 may perform frequency conversion after generating the transmission signal of each OAM mode by digital processing. Alternatively, the OAM mode generation device 170 may generate a transmission signal for each OAM mode using an analog circuit after performing frequency conversion. Alternatively, the OAM mode generation device 170 may perform frequency conversion after generating an OAM mode transmission signal using an analog circuit. OAM mode generation device 170 multiplexes the generated transmission signals of each OAM mode and inputs the multiplexed signals to RF chain 180.
  • the RF chain 180 frequency-converts and amplifies the transmission signal input from the OAM mode generation device 170, and then inputs the signal to the UCA 190.
  • the UCA 190 is an antenna in which M antenna elements are arranged in a circle.
  • the UCA 190 transmits and receives an OAM multiplex signal obtained by multiplexing transmission signals of each OAM mode.
  • FIG. 4 is a diagram showing an example of a connection configuration of the OAM mode generation device 170, RF chain 180, and UCA 190 in the transmitting device 100.
  • the UCA 190 is an antenna in which M antenna elements 191 are arranged in a circle.
  • the M antenna elements 191 are respectively referred to as antenna elements 191-1 to 191-M.
  • the OAM mode generation device 170 has output ports #1 to #M.
  • OAM mode generation device 170 adds a DFT transformation matrix according to the mode to each signal of modes 0 to N, and generates a transmission signal to be transmitted from each of antenna elements 191-1 to 191-M.
  • the OAM mode generation device 170 multiplexes the signals of each mode transmitted from the antenna element 191-m for each antenna element 191-m (m is an integer between 1 and M), and outputs the multiplexed signal #m to the output port #. Output from m.
  • the RF chain 180 has RF chains #1 to #M.
  • RF chains #1 to #M each receive signals #1 to #M from OAM mode generation device 170.
  • RF chain #m converts the frequency of signal #m, amplifies it, and then outputs it to antenna element 191-m.
  • UCA 190 transmits signals #1 to #M input from RF chain 180 as radio waves from antenna elements 191-1 to 191-M, respectively.
  • FIG. 5 is a diagram showing an example of the functional configuration of the transmission control device 120.
  • the transmission control device 120 includes a communication performance acquisition section 121, a transmission OAM mode determination section 122, a multiplexing number determination section 123, and a transmission signal parameter determination section 124.
  • the communication performance acquisition unit 121 is a device that acquires communication characteristic information.
  • Communication characteristic information indicates characteristics of communication between transmitting device 100 and receiving device 200.
  • the characteristics indicated by the communication characteristic information include, for example, the distance between transmitter and receiver, the received signal power to interference and noise ratio (SINR), and the interference between modes.
  • SINR received signal power to interference and noise ratio
  • the transmitting/receiving distance is the distance between the transmitting device 100 and the receiving device 200.
  • the transmission OAM mode determination unit 122 determines the transmission OAM mode based on the communication characteristic information, and inputs information on the determined OAM mode to the transmission parameter determination device 140.
  • the multiplexing number determining unit 123 determines, for example, the mode multiplexing number and modulation level number that maximizes the transmission capacity based on the communication characteristic information, and transmits information on the determined mode multiplexing number and modulation level number to the transmission parameter determining device. 140.
  • the transmission signal parameter determination unit 124 determines the value of a transmission signal parameter such as a coding rate based on the communication characteristic information, and inputs information on the determined value of the transmission signal parameter to the transmission parameter determination device 140.
  • the transmission OAM mode determination section 122, the multiplex number determination section 123, and the transmission signal parameter determination section 124 use, for example, the distance between transmission and reception and the reception SINR as communication characteristic information.
  • processing is performed in the order of the communication performance acquisition unit 121, the transmission OAM mode determination unit 122, and the multiplex number determination unit 123, but the order may be changed.
  • FIG. 6 is a diagram showing an example of the functional configuration of the transmission parameter determining device 140.
  • Transmission parameter determination device 140 determines the roll-off rate of the roll-off filter based on at least a portion of the parameter values input from transmission control device 120 so as to reduce PAPR.
  • the transmission parameter determination device 140 includes a communication parameter acquisition section 141, a PAPR information holding section 142, a roll-off rate determination section 143, and a symbol rate determination section 144.
  • the communication parameter acquisition unit 141 acquires information on parameters such as the number of modulation levels, the number of mode multiplexing, and the transmission OAM mode notified from the transmission control device 120, and notifies the roll-off rate determination unit 143 of the information on these parameters. do.
  • the PAPR information holding unit 142 is a storage medium that holds PAPR information indicating the relationship between the roll-off rate, the mode multiplexing number, the OAM mode, and the PAPR.
  • the PAPR information holding unit 142 may hold PAPR information for each modulation method. For example, PAPR information generated by calculating the relationship between the roll-off rate, the mode multiplexing number, the OAM mode, and the PAPR may be stored in the PAPR information holding unit 142 in advance. Alternatively, the PAPR information holding unit 142 may sequentially calculate the above relationship and store it as PAPR information.
  • the roll-off rate determining unit 143 determines the roll-off rate based on the information on the mode multiplexing number and transmission OAM mode notified from the communication parameter acquiring unit 141 and the information stored in the PAPR information holding unit 142. Specifically, the roll-off rate determination unit 143 executes an algorithm described in FIG. 14, which will be described later, to determine the roll-off rate.
  • the symbol rate determining unit 144 determines the symbol rate based on the roll-off rate determined by the roll-off rate determining unit 143.
  • FIG. 7 is a diagram showing the relationship among the roll-off rate, mode multiplexing number, OAM mode, and PAPR in the case of a 16QAM (Quadrature Amplitude Modulation) signal.
  • Each value in [ ] shown in the legend represents the type of OAM mode.
  • the number of numbers in [ ] represents the number of mode multiplexing. For example, [0 1 -1] represents OAM modes 0, 1, -1 and mode multiplexing number 3.
  • the PAPR information holding unit 142 stores, for example, PAPR information representing the relationship shown in FIG. 7 in association with modulation method information.
  • FIG. 8 is a diagram showing an example of a lookup table (LUT).
  • the PAPR information holding unit 142 may store the lookup table shown in FIG. 8 as PAPR information in association with the modulation method information.
  • the lookup table is data that associates the mode multiplexing number with the roll-off rate that minimizes the PAPR.
  • the symbol L in the graph shown in FIG. 7 is a point connecting points where PAPR is minimum for each multiplex number. Based on this point on the code L, the relationship between the mode multiplexing number and the roll-off rate that minimizes the PAPR can be obtained.
  • the lookup table may be created using preliminary simulation evaluation results, or may be created based on actual measured values.
  • FIG. 9 is a diagram showing an example of the functional configuration of the receiving device 200.
  • the receiving device 200 includes a UCA 210, an RF chain 220, an OAM mode separation device 230, a received signal processing device 240, a roll-off rate acquisition device 250, a nonlinear distortion estimation device 260, a demodulator 270, and a nonlinear distortion notification device. device 280.
  • the UCA 210 receives radio waves transmitted from the transmitting device 100 and inputs them to the RF chain 220.
  • the RF chain 220 performs frequency conversion and amplification of the signal input from the UCA 210 and inputs the signal to the OAM mode separation device 230 .
  • OAM mode separator 230 is an analog circuit or digital signal processing device that provides an IDFT transformation matrix.
  • OAM mode separation device 230 separates the signal input from RF chain 220 into signals of each mode, and inputs the separated signals to received signal processing device 240 .
  • the received signal processing device 240 samples the signal notified from the roll-off rate acquisition device 250 or input from the OAM mode separation device 230 based on a predetermined symbol rate. Further, the received signal processing device 240 performs band-limiting filter processing on the sampled signal based on the roll-off rate notified from the roll-off rate acquisition device 250 or based on a predetermined roll-off rate, or uses an analog filter. Performs band-limiting filter processing. Received signal processing device 240 inputs the filtered signal to nonlinear distortion estimation device 260. The roll-off rate acquisition device 250 notifies the received signal processing device 240 of the roll-off rate and symbol rate information transmitted from the transmission parameter notification device 150 of the transmitting device 100.
  • the nonlinear distortion estimating device 260 estimates nonlinear distortion based on the constellation of the signal input from the received signal processing device 240.
  • Nonlinear distortion estimating device 260 inputs the signal input from received signal processing device 240 as is to demodulator 270 .
  • Demodulator 270 demodulates the signal input from nonlinear distortion estimation device 260.
  • Nonlinear distortion notification device 280 converts the nonlinear distortion information indicating the presence or absence of nonlinear distortion notified from nonlinear distortion estimation device 260 into an appropriate format, and outputs it to transmitting device 100 via radio or a backbone line.
  • FIG. 10 shows a configuration example of the nonlinear distortion estimation device 260.
  • the nonlinear distortion estimation device 260 includes a constellation extraction section 261, an EVM (Error Vector Magnitude) calculation section 262, and an EVM comparison section 263.
  • the constellation extraction unit 261 classifies signal points based on the voltage of the signal points of the received signal.
  • the EVM calculation unit 262 calculates the EVM of each signal point.
  • the EVM comparison unit 263 compares the EVM of each signal point and determines whether nonlinear distortion occurs.
  • FIG. 11 is a sequence diagram showing processing by the transmitting device 100 of the wireless transmission device 11 and the receiving device 200 of the wireless transmission device 12.
  • the transmission parameter determining device 140 of the transmitting device 100 reads the roll-off rate that minimizes the PAPR from the lookup table stored in the PAPR information holding unit 142, and sets it as an initial value (step S11).
  • the transmission control device 120 of the transmitting device 100 determines the values of parameters such as the number of mode multiplexing, the transmission OAM mode, the number of modulation levels, and the symbol rate.
  • the roll-off rate determination unit 143 determines the mode multiplexing number from the lookup table stored in the PAPR information storage unit 142 corresponding to the encoding method information specified by the value of the parameter notified from the transmission control device 120. Read out the roll-off rate using as the search condition. Note that instead of the information on the number of modes to be multiplexed, information on the combination of the number of modes to be multiplexed and the OAM mode may be used in the lookup table.
  • the roll-off rate determining unit 143 reads the roll-off rate from the lookup table using the mode multiplexing number and the transmission OAM mode as search conditions. Further, the symbol rate determining unit 144 determines a symbol rate corresponding to the read roll-off rate.
  • the transmitting device 100 transmits an OAM multiplex signal generated using the parameter values determined by the transmission control device 120 and the roll-off rate and symbol rate determined by the transmission parameter determining device 140 (step S12).
  • the receiving device 200 receives the OAM multiplex signal transmitted by the transmitting device 100.
  • the nonlinear distortion estimating device 260 of the receiving device 200 estimates the presence or absence of nonlinear distortion based on the received signal (step S13).
  • the nonlinear distortion notification device 280 of the receiving device 200 notifies the transmitting device 100 of nonlinear distortion information indicating the estimation result in step S13 (step S14).
  • the nonlinear distortion acquisition device 110 of the transmitting device 100 acquires the nonlinear distortion information notified from the receiving device 200.
  • the transmission control device 120 of the transmitting device 100 inputs the nonlinear distortion information acquired by the nonlinear distortion acquisition device 110 to the transmission parameter determination device 140.
  • the roll-off rate determining unit 143 changes the roll-off rate depending on the presence or absence of non-linear distortion indicated by the non-linear distortion information.
  • the symbol rate determining unit 144 changes the symbol rate based on the changed roll-off rate (step S15).
  • the transmitting device 100 generates and transmits an OAM multiplex signal using the changed roll-off rate and symbol rate (step S16).
  • UCA 210 of receiving device 200 receives the OAM multiplex signal transmitted from transmitting device 100.
  • Transmission parameter notification device 150 of transmitting device 100 notifies information on the roll-off rate and symbol rate to receiving device 200 in parallel with step S16 (step S17).
  • Roll-off rate acquisition device 250 of receiving device 200 receives information on the roll-off rate and symbol rate transmitted from transmitting device 100, and outputs it to received signal processing device 240.
  • the receiving device 200 performs reception processing on the received OAM multiplex signal using the notified roll-off rate and symbol rate.
  • the demodulator 270 of the receiving device 200 demodulates the received signal (step S18).
  • the receiving device 200 may repeat the processing from step S13, estimate the presence or absence of nonlinear distortion in the received OAM multiplexed signal, and notify the transmitting device 100 again.
  • the wireless communication system 1 performs the processes of steps S12 to S18 periodically or every time a signal frame is transmitted. Thereby, the wireless communication system 1 adaptively controls the roll-off rate and symbol rate according to the amount of nonlinear distortion.
  • FIG. 12 shows an example of a constellation of a 16QAM signal subjected to nonlinear distortion.
  • the nonlinear distortion received by the transmission RF has a large effect on the outer signal points P1 to P4 where the voltage is high. Therefore, the nonlinear distortion estimation device 260 estimates the presence or absence of nonlinear distortion by comparing the average EVM of the outer signal points P1 to P4 and the average EVM of the inner signal points Q1 to Q4.
  • the average EVM is the mean squared error normalized by the average power of the signal.
  • Signal points P1 to P4 are collectively referred to as signal point P
  • signal points Q1 to Q4 are collectively referred to as signal point Q.
  • FIG. 13 is a flow diagram showing an algorithm for estimating the amount of nonlinear distortion in the nonlinear distortion estimation device 260.
  • the signal point P is classified into signal points P1, P2, P3, and P4 depending on the combination of the positive/negative of x[n] and the positive/negative of y[n]. Further, as shown in FIG. 12, the constellation extraction unit 261 sets the signal point n of
  • the signal point Q is also classified into signal points Q1, Q2, Q3, and Q4 depending on the combination of the positive/negative of x[n] and the positive/negative of y[n].
  • the EVM calculation unit 262 of the nonlinear distortion estimation device 260 calculates the average EVM of the outer signal point P and the average EVM of the inner signal point Q (step S32). For example, the EVM calculation unit 262 calculates the average error from the standard of each signal point as the average EVM using the original signal point shared between the transmitting device 100 and the receiving device 200 in advance using the preamble of the OAM multiplexed signal as a standard. do. The criteria differ for each classification of signal points P1, P2, P3, P4, Q1, Q2, Q3, and Q4. Alternatively, the EVM calculation unit 262 may use the average value of the voltage of the signal point for each classification as a reference, and simply estimate the average error as the average EVM from that reference.
  • the EVM comparison unit 263 of the nonlinear distortion estimating device 260 compares the average EVM of the outer signal point P and the average EVM of the inner signal point Q, and determines whether nonlinear distortion has occurred (step S33). Specifically, if the EVM comparison unit 263 determines that the following equation (1) is satisfied, it considers that nonlinear distortion has occurred.
  • the EVM comparison unit 263 notifies the transmitting device 100 of nonlinear distortion information indicating the occurrence of nonlinear distortion through the nonlinear distortion notification device 280.
  • the EVM comparison unit 263 notifies the transmitting device 100 of nonlinear distortion information indicating that nonlinear distortion has not occurred through the nonlinear distortion notification device 280.
  • the nonlinear distortion notification device 280 notifies the transmission device 100 of the nonlinear distortion information input from the EVM comparison unit 263 via wireless or a backbone line (step S14 in FIG. 11).
  • ⁇ is the margin. ⁇ is, for example, a value of 1 dB, but may be arbitrarily designed.
  • the nonlinear distortion notification device 280 of the receiving device 200 calculates the average EVM of the outer signal point P and the average EVM of the inner signal point Q, or the average EVM of the outer signal point P and the average EVM of the inner signal point Q.
  • the transmitting device 100 may be notified of the nonlinear distortion information in which the difference is set.
  • the transmission parameter determining device 140 of the transmitting device 100 acquires information on the difference between the average EVM of the outer signal point P and the average EVM of the inner signal point Q based on the received nonlinear distortion information, and the obtained difference is ⁇
  • the presence or absence of nonlinear distortion may be determined based on whether or not it exceeds .
  • FIG. 14 is a flow diagram showing a roll-off rate and symbol rate determination algorithm executed by transmission parameter determining device 140 of transmitting device 100.
  • the algorithm shown in FIG. 14 determines the roll-off rate ⁇ and symbol rate ⁇ for the purpose of improving the data rate.
  • the data rate is improved by changing the roll-off rate ⁇ and the symbol rate ⁇ depending on the presence or absence of the amount of nonlinear distortion estimated by the receiving device 200.
  • the roll-off rate determining unit 143 of the transmission parameter determining device 140 refers to the lookup table held in the PAPR information holding unit 142, and selects a value corresponding to the number of mode multiplexing or the number of mode multiplexing and the transmission OAM mode. A corresponding roll-off rate is selected and set as an initial value (step S51). This roll-off rate is a value that minimizes PAPR.
  • the symbol rate determination unit 144 sets a symbol rate corresponding to the initial roll-off rate (step S52). The symbol rate is predetermined according to the roll-off rate as a value that maximizes the data rate within the limited range of occupied bandwidth.
  • the roll-off rate determining unit 143 sets a variable i representing the number of repetitions to 0 (step S53).
  • the communication parameter acquisition unit 141 of the transmitting device 100 acquires the nonlinear distortion information that the nonlinear distortion acquisition device 110 receives from the receiving device 200 (step S54).
  • the roll-off rate determining unit 143 determines whether the acquired nonlinear distortion information indicates that nonlinear distortion is present (step S55).
  • step S55 When the roll-off rate determining unit 143 determines that the nonlinear distortion information indicates no nonlinear distortion (step S55: NO), it performs the process of step S56. That is, the roll-off rate determination unit 143 updates the roll-off rate to a value that is lowered by ⁇ from the current value ⁇ . Further, the symbol rate determining unit 144 changes the symbol rate to ⁇ ( ⁇ ) corresponding to the updated roll-off rate ⁇ (step S56). The roll-off rate determining unit 143 adds 1 to the value of the variable i (step S57). The transmission parameter determining device 140 notifies the roll-off filter applying device 160 of the changed roll-off rate and symbol rate information, and repeats the processing from step S54.
  • step S58 determines whether the variable i is 0 (step S58). If the variable i is 0, the current rolloff rate is the initial rolloff rate that minimizes PAPR. Therefore, when the roll-off rate determining unit 143 determines that the variable i is 0 (step S58: YES), it instructs the signal processing device 130 to lower the transmission power (step S59). Upon receiving this instruction, the signal processing device 130 reduces the amplitude of the signal output to the roll-off filter applying device 160.
  • the roll-off rate determining unit 143 determines that the variable i is not 0 (step S58: NO), it performs the process of step S60. That is, the roll-off rate determination unit 143 updates the roll-off rate to a value that is increased by ⁇ from the current value ⁇ . Furthermore, the symbol rate determining unit 144 sets the symbol rate to ⁇ ( ⁇ ) corresponding to the updated roll-off rate ⁇ (step S60). The transmission parameter determining device 140 notifies the roll-off filter application device 160 of the changed roll-off rate and symbol rate information.
  • ⁇ is the step width of the roll-off rate.
  • ⁇ ( ⁇ ) is the symbol rate that maximizes the data rate under the occupied bandwidth limit for the roll-off rate ⁇ .
  • the relationship between the roll-off rate and the symbol rate is, for example, calculated in advance and stored in the transmitting device 100, or is calculated each time by the transmission parameter determining device 140.
  • the algorithm shown in FIG. 14 may be executed only at the timing of starting communication, or may be executed multiple times at appropriate intervals.
  • FIG. 15 is a device configuration diagram showing an example of the hardware configuration of the transmitting device 100 and the receiving device 200.
  • the transmitting device 100 and the receiving device 200 include a processor 71, a storage unit 72, a communication interface 73, and a user interface 74.
  • the processor 71 is a central processing unit that performs calculations and control.
  • Processor 71 is, for example, a CPU.
  • the processor 71 reads a program from the storage unit 72 and executes it. Some of the functions of the transmitting device 100 and the receiving device 200 may be realized using hardware such as an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array).
  • the storage unit 72 further includes a work area when the processor 71 executes various programs.
  • the communication interface 73 is communicably connected to other devices.
  • the user interface 74 is an input device such as a keyboard, a pointing device (mouse, tablet, etc.), a button, a touch panel, or a display device such as a display. A human operation is input through the user interface 74 .
  • the wireless communication system includes a transmitting device and a receiving device.
  • the transmitting device includes a determining section, a filter applying section, a transmitting section, and a changing section.
  • the determining unit corresponds to, for example, the transmission parameter determining device 140 of the embodiment.
  • the determining unit determines the roll-off rate based on at least part of a parameter representing a modulation method of an OAM multiplex signal obtained by multiplexing signals using each OAM mode.
  • the filter application unit corresponds to, for example, the roll-off filter application device 160 of the embodiment.
  • the filter application section applies roll-off filter processing to the transmission signal using the roll-off rate determined by the determination section.
  • the transmitter corresponds to, for example, the OAM mode generator 170, RF chain 180, and UCA 190 of the embodiment.
  • the transmitter generates an OAM multiplex signal according to a modulation scheme from the transmission signal subjected to roll-off filter processing by the filter application unit, and transmits the generated OAM multiplex signal.
  • the changing unit corresponds to, for example, the transmission parameter determining device 140 of the embodiment.
  • the changing unit changes the roll-off rate based on the estimation result of nonlinear distortion of the OAM multiplexed signal in the receiving device.
  • the determining unit may include an information holding unit, a roll-off rate determining unit, and a symbol rate determining unit.
  • the information holding unit corresponds to, for example, the PAPR information holding unit 142 of the embodiment.
  • the information holding unit holds information indicating the correspondence between roll-off rates and parameters.
  • the roll-off rate determining unit reads the roll-off rate from the information holding unit based on at least part of the parameters representing the modulation method.
  • the symbol rate determining section determines the symbol rate based on the roll-off rate read by the roll-off rate determining section.
  • the filter application section applies roll-off filter processing using the roll-off rate read by the roll-off rate determination section to the transmission signal using the symbol rate determined by the symbol rate determination section.
  • the parameter is one or more of mode multiplexing number, transmission mode, modulation level number, and symbol rate.
  • the receiving device includes a receiving section, an estimating section, and a notifying section.
  • the receiving unit corresponds to, for example, the UCA 210, RF chain 220, OAM mode separation device 230, and received signal processing device 240 of the embodiment.
  • the receiving unit performs a receiving process on the OAM multiplex signal received from the transmitting device.
  • the estimator corresponds to, for example, the nonlinear distortion estimator 260 of the embodiment.
  • the estimator estimates nonlinear distortion of the OAM multiplex signal received and processed by the receiver.
  • the estimating unit may estimate the nonlinear distortion based on the difference between the mean square error of high voltage signal points and the mean square error of low voltage signal points in the constellation of the OAM multiplex signal received and processed by the receiving unit. good.
  • the notification unit corresponds to, for example, the nonlinear distortion notification device 280 of the embodiment.
  • the notification unit notifies the transmitting device of the estimation result by the estimation unit.
  • the receiving unit receives from the transmitting device an OAM multiplexed signal generated from a transmitted signal to which roll-off filter processing using a roll-off rate changed based on the estimation result has been applied.
  • the estimation unit may include a classification unit, a calculation unit, and a comparison unit.
  • the classification unit corresponds to, for example, the constellation extraction unit 261 of the embodiment.
  • the classification unit classifies the signal points based on the voltages of the signal points of the OAM multiplex signal received and processed by the reception unit.
  • the calculation unit corresponds to, for example, the EVM calculation unit 262 of the embodiment.
  • the calculation unit calculates an error vector amplitude of a first signal point that is a signal point classified as a high voltage, and an error vector amplitude of a second signal point that is a signal point classified as a low voltage.
  • the comparison unit corresponds to, for example, the EVM comparison unit 263 of the embodiment.
  • the comparison unit determines that nonlinear distortion has occurred when the difference between the mean square error of the error vector amplitude of the first signal point and the mean square error of the error vector amplitude of the second signal point is greater than or equal to a predetermined value. to decide.
  • Wireless communication system 11 Wireless transmission device 12 Wireless transmission device 71 Processor 72 Storage unit 73 Communication interface 74 User interface 100 Transmission device 110 Acquisition device 120 Transmission control device 121 Communication performance acquisition unit 122 Transmission OAM mode determination unit 123 Multiplex number determination unit 124 Transmission signal parameter determination section 130 Signal processing device 140 Transmission parameter determination device 141 Communication parameter acquisition section 142 PAPR information holding section 143 Roll-off rate determination section 144 Symbol rate determination section 150 Transmission parameter notification device 160 Roll-off filter application device 170 OAM mode generation Device 180 RF chain 190 UCA 191-1 to 191-M Antenna element 200 Receiving device 210 UCA 220 RF chain 230 OAM mode separation device 240 Received signal processing device 250 Roll-off rate acquisition device 260 Estimation device 261 Constellation extraction section 262 EVM calculation section 263 EVM comparison section 270 Demodulator 280 Notification device

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Transmitters (AREA)

Abstract

This transmission device comprises a determination unit, a filter application unit, a transmission unit, and a changing unit. The determination unit determines a roll-off rate on the basis of at least some of parameters representative of the modulation method changes of an OAM multiplexed signal. The filter application unit uses the determined roll-off rate to apply a roll-off filtering to a transmission signal. The transmission unit transmits an OAM multiplexed signal generated, according to a modulation method, from the transmission signal as roll-off filtered. The changing unit changes roll-off rates on the basis of whether a nonlinear distortion notified of by a reception device is present or not. This reception device comprises a reception unit, an estimation unit, and a notification unit. The estimation unit estimates the nonlinear distortion of the OAM multiplexed signal as reception-processed by the reception unit. The notification unit notifies the transmission device of the estimation result.

Description

無線通信方法、無線通信システム、送信装置及び受信装置Wireless communication method, wireless communication system, transmitter and receiver
　本発明は、無線通信方法、無線通信システム、送信装置及び受信装置に関する。 The present invention relates to a wireless communication method, a wireless communication system, a transmitter, and a receiver.
　近年、通信容量の向上のため軌道角運動量（Orbital Angular Momentum：ＯＡＭ）を用いた無線信号の空間多重伝送技術の検討が進められている（例えば、非特許文献１参照）。ＯＡＭを持つ電磁波は、伝搬軸を中心に伝搬方向に沿って等位相面がらせん状に分布する。異なるＯＡＭモードを持ち、かつ、同一方向に伝搬する電磁波は、回転軸方向において空間位相分布が直交する。そのため、異なる信号系列で変調された各ＯＡＭモードの信号を受信装置において分離することにより、信号を空間多重することが可能である。 In recent years, in order to improve communication capacity, studies are underway on spatial multiplexing transmission technology for wireless signals using orbital angular momentum (OAM) (see, for example, Non-Patent Document 1). In an electromagnetic wave having OAM, equal phase planes are distributed in a spiral shape along the propagation direction with the propagation axis as the center. Electromagnetic waves having different OAM modes and propagating in the same direction have spatial phase distributions that are orthogonal in the rotation axis direction. Therefore, it is possible to spatially multiplex the signals by separating the signals of each OAM mode modulated with different signal sequences in the receiving device.
　このＯＡＭ多重伝送は、複数のアンテナ素子を等間隔に円状に配置した円形アレーアンテナ（Uniform circular array：ＵＣＡ）を用いて複数のＯＡＭモードを生成及び多重して送信することにより実現できる（例えば、非特許文献２）。複数のＯＡＭモードの信号生成及び分離には、例えば離散フーリエ変換（Discrete Fourier transform：ＤＦＴ）行列及び逆離散フーリエ変換（Inverse DFT：ＩＤＦＴ）行列が使用される。 This OAM multiplex transmission can be realized by generating and multiplexing multiple OAM modes using a circular array antenna (UCA) in which multiple antenna elements are arranged in a circle at regular intervals (for example, , Non-Patent Document 2). For example, a discrete Fourier transform (DFT) matrix and an inverse discrete Fourier transform (IDFT) matrix are used for signal generation and separation of multiple OAM modes.
　ＯＡＭ多重伝送では、送信装置が複数の信号をＯＡＭ多重して伝送する。そのため、各モードの変調信号の信号点位相が同位相で合成された場合に、送信信号のピーク電力対平均電力比（Peak-to-average power ratio：ＰＡＰＲ）が上昇する。ＰＡＰＲの高い信号を電力増幅器で増幅する場合、入力電力のバックオフを大きくとる必要があるため、出力電力の低下が問題となる。その結果として、受信ＳＮＲが低下し信号品質が劣化する。 In OAM multiplex transmission, a transmitting device OAM multiplexes multiple signals and transmits them. Therefore, when the signal point phases of the modulated signals of each mode are combined in the same phase, the peak-to-average power ratio (PAPR) of the transmission signal increases. When a signal with a high PAPR is amplified by a power amplifier, it is necessary to provide a large back-off of input power, so a reduction in output power becomes a problem. As a result, the received SNR decreases and signal quality deteriorates.
　上記事情に鑑み、本発明は、ＰＡＰＲを低減しながらデータレートを向上することができる無線通信方法、無線通信システム、送信装置及び受信装置を提供することを目的としている。 In view of the above circumstances, an object of the present invention is to provide a wireless communication method, a wireless communication system, a transmitter, and a receiver that can improve the data rate while reducing PAPR.
　本発明の一態様の無線通信方法は、送信装置が、各ＯＡＭ（Orbital Angular Momentum）モードを用いた信号を多重したＯＡＭ多重信号の変調方式を表すパラメータの少なくとも一部に基づいてロールオフ率を決定する決定ステップと、前記送信装置が、前記決定ステップにおいて決定された前記ロールオフ率を用いて送信信号にロールオフフィルタ処理を適用するフィルタ適用ステップと、前記送信装置が、前記フィルタ適用ステップにおいて前記ロールオフフィルタ処理が行われた前記送信信号から前記変調方式に従ってＯＡＭ多重信号を生成し、生成された前記ＯＡＭ多重信号を送信する送信ステップと、受信装置が、前記送信装置から受信した前記ＯＡＭ多重信号の受信処理を行う受信処理ステップと、前記受信装置が、前記受信処理ステップにおいて受信処理された前記ＯＡＭ多重信号の非線形歪みを推定する推定ステップと、前記受信装置が、前記推定ステップにおける推定結果を前記送信装置に通知する通知ステップと、前記送信装置が、前記受信装置から通知された前記推定結果に基づいて前記ロールオフ率を変更する変更ステップと、を有する。 In a wireless communication method according to one aspect of the present invention, a transmitting device determines a roll-off rate based on at least part of a parameter representing a modulation method of an OAM multiplexed signal obtained by multiplexing signals using each OAM (Orbital Angular Momentum) mode. a determining step in which the transmitting device applies roll-off filter processing to a transmission signal using the roll-off rate determined in the determining step; a transmitting step of generating an OAM multiplexed signal according to the modulation method from the transmission signal subjected to the roll-off filter processing and transmitting the generated OAM multiplexed signal; and a receiving device transmitting the OAM multiplexed signal received from the transmitting device. a reception processing step of performing reception processing of a multiplexed signal; an estimation step in which the receiving device estimates nonlinear distortion of the OAM multiplexed signal received in the reception processing step; The method includes a notification step of notifying the transmitting device of the result, and a changing step of the transmitting device changing the roll-off rate based on the estimation result notified from the receiving device.
　本発明の一態様は、送信装置と受信装置とを有する無線通信システムであって、前記送信装置は、各ＯＡＭ（Orbital Angular Momentum）モードを用いた信号を多重したＯＡＭ多重信号の変調方式を表すパラメータの少なくとも一部に基づいてロールオフ率を決定する決定部と、前記決定部が決定した前記ロールオフ率を用いて送信信号にロールオフフィルタ処理を適用するフィルタ適用部と、前記フィルタ適用部により前記ロールオフフィルタ処理が行われた前記送信信号から前記変調方式に従ってＯＡＭ多重信号を生成し、生成された前記ＯＡＭ多重信号を送信する送信部と、前記受信装置における前記ＯＡＭ多重信号の非線形歪みの推定結果に基づいて前記ロールオフ率を変更する変更部とを備え、前記受信装置は、前記送信装置から受信した前記ＯＡＭ多重信号の受信処理を行う受信部と、前記受信部が受信処理した前記ＯＡＭ多重信号の非線形歪みを推定する推定部と、前記推定部による推定結果を前記送信装置に通知する通知部とを備える。 One aspect of the present invention is a wireless communication system including a transmitting device and a receiving device, wherein the transmitting device expresses a modulation method of an OAM multiplexed signal in which signals using each OAM (Orbital Angular Momentum) mode are multiplexed. a determining unit that determines a roll-off rate based on at least a portion of a parameter; a filter applying unit that applies roll-off filter processing to a transmission signal using the roll-off rate determined by the determining unit; and the filter applying unit a transmitting unit that generates an OAM multiplex signal from the transmission signal subjected to the roll-off filter processing according to the modulation method and transmits the generated OAM multiplex signal; and a nonlinear distortion of the OAM multiplex signal in the receiving device. a changing unit that changes the roll-off rate based on an estimation result of the OAM multiplexed signal received from the transmitting device; The apparatus includes an estimating section that estimates nonlinear distortion of the OAM multiplexed signal, and a notification section that notifies the transmitting device of the estimation result by the estimating section.
　本発明の一態様の送信装置は、各ＯＡＭ（Orbital Angular Momentum）モードを用いた信号を多重したＯＡＭ多重信号の変調方式を表すパラメータの少なくとも一部に基づいてロールオフ率とシンボルレートを決定する決定部と、前記決定部が決定した前記ロールオフ率を用いて送信信号にロールオフフィルタ処理を適用するフィルタ適用部と、前記フィルタ適用部により前記ロールオフフィルタ処理が行われた前記送信信号からＯＡＭ多重信号を生成し、生成された前記ＯＡＭ多重信号を送信する送信部と、受信装置における前記ＯＡＭ多重信号の非線形歪みの推定結果に基づいて前記ロールオフ率を変更する変更部と、を備える。 A transmitting device according to one embodiment of the present invention determines a roll-off rate and a symbol rate based on at least a part of parameters representing a modulation method of an OAM multiplexed signal obtained by multiplexing signals using each OAM (Orbital Angular Momentum) mode. a determination unit; a filter application unit that applies roll-off filter processing to a transmission signal using the roll-off rate determined by the determination unit; and a filter application unit that applies roll-off filter processing to the transmission signal using the roll-off rate determined by the determination unit; A transmitting unit that generates an OAM multiplexed signal and transmits the generated OAM multiplexed signal, and a changing unit that changes the roll-off rate based on an estimation result of nonlinear distortion of the OAM multiplexed signal in a receiving device. .
　本発明の一態様の受信装置は、各ＯＡＭ（Orbital Angular Momentum）モードを用いた信号を多重したＯＡＭ多重信号を送信装置から受信し、受信した前記ＯＡＭ多重信号の受信処理を行う受信部と、前記受信部が受信処理した前記ＯＡＭ多重信号のコンスタレーションにおける高い電圧の信号点の平均２乗誤差及び低い電圧の信号点の平均２乗誤差の差分に基づいて非線形歪みを推定する推定部と、前記推定部による推定結果を前記送信装置に通知する通知部と、を備え、前記受信部は、前記推定結果に基づいて変更されたロールオフ率を用いたロールオフフィルタ処理が適用された送信信号から生成されたＯＡＭ多重信号を前記送信装置から受信する。 A receiving device according to one aspect of the present invention includes a receiving unit that receives an OAM multiplexed signal in which signals using each OAM (Orbital Angular Momentum) mode are multiplexed from a transmitting device, and performs reception processing on the received OAM multiplexed signal; an estimating unit that estimates nonlinear distortion based on a difference between a mean square error of a high voltage signal point and a mean square error of a low voltage signal point in the constellation of the OAM multiplex signal received and processed by the receiving unit; a notification unit that notifies the transmitting device of the estimation result by the estimation unit, the receiving unit transmitting a transmission signal to which roll-off filter processing using a roll-off rate changed based on the estimation result is applied. receives an OAM multiplex signal generated from the transmitting device.
　本発明により、ＯＡＭ空間多重伝送において、ＰＡＰＲを低減しつつデータレートを向上させることが可能となる。 According to the present invention, it is possible to improve the data rate while reducing PAPR in OAM spatial multiplexing transmission.
ＯＡＭモードの信号を生成するためのＵＣＡの位相設定例を示す図である。FIG. 6 is a diagram illustrating an example of UCA phase settings for generating an OAM mode signal. 本発明の実施形態における無線通信システムの構成図である。1 is a configuration diagram of a wireless communication system in an embodiment of the present invention. 同実施形態における送信装置の構成例を示す図である。It is a diagram showing an example of the configuration of a transmitting device in the same embodiment. 同実施形態における送信装置のＯＡＭモード生成装置、ＲＦチェーン及びＵＣＡの接続構成例を示す図である。FIG. 3 is a diagram illustrating an example of a connection configuration of an OAM mode generation device, an RF chain, and a UCA of a transmitting device in the same embodiment. 同実施形態における送信制御装置の機能構成例を示す図である。It is a figure showing an example of functional composition of a transmission control device in the same embodiment. 同実施形態における送信パラメータ決定装置の機能構成例を示す図である。It is a figure showing an example of functional composition of a transmission parameter decision device in the same embodiment. 同実施形態におけるロールオフ率、モード多重数、ＯＡＭモード及びＰＡＰＲの関係の例を示す図である。It is a figure which shows the example of the relationship between roll-off rate, mode multiplexing number, OAM mode, and PAPR in the same embodiment. 同実施形態におけるルックアップテーブルの例を示す図である。It is a figure which shows the example of a lookup table in the same embodiment. 同実施形態における受信装置の構成例を示す図である。It is a figure showing an example of composition of a receiving device in the same embodiment. 同実施形態における非線形歪み推定装置の機能構成例を示す図である。It is a figure showing an example of functional composition of a nonlinear distortion estimating device in the same embodiment. 同実施形態における無線通信システムの処理を示すシーケンス図である。FIG. 3 is a sequence diagram showing processing of the wireless communication system in the same embodiment. 同実施形態における非線形歪みを受けた受信コンスタレーションの例を示す図である。FIG. 6 is a diagram illustrating an example of a reception constellation subjected to nonlinear distortion in the same embodiment. 同実施形態における受信コンスタレーションから非線形歪みの有無を推定するアルゴリズムを示すフロー図である。FIG. 3 is a flow diagram showing an algorithm for estimating the presence or absence of nonlinear distortion from a received constellation in the same embodiment. 同実施形態におけるロールオフ率及びシンボルレートを決定するアルゴリズムを示すフロー図である。FIG. 3 is a flow diagram showing an algorithm for determining a roll-off rate and a symbol rate in the same embodiment. 同実施形態における送信装置及び受信装置のハードウェア構成を示す図である。It is a diagram showing the hardware configuration of a transmitting device and a receiving device in the same embodiment.
　以下、図面を参照しながら本発明の実施形態を詳細に説明する。以下で説明する実施形態は一例にすぎず、本発明が適用される実施形態は、以下の実施の形態に限られるわけではない。本実施形態は、電磁波の軌道角運動量（Orbital Angular Momentum：ＯＡＭ）を用いて無線信号を空間多重伝送する技術に関連する。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The embodiments described below are merely examples, and the embodiments to which the present invention is applied are not limited to the following embodiments. The present embodiment relates to a technology for spatially multiplexing and transmitting wireless signals using orbital angular momentum (OAM) of electromagnetic waves.
　本実施形態の送信装置は、適応制御部と、フィルタ適用部と、通知部と、送信部とを有する。適応制御部は、決定部と変更部とを有する。決定部は、モード多重数に基づいて、各ＯＡＭモードの送信信号に適用する帯域制限フィルタ（ロールオフフィルタ）のロールオフ率を決定する。フィルタ適用部は、決定されたロールオフ率の帯域制限フィルタを各ＯＡＭモードの送信信号に適用するフィルタ処理を行う。通知部は、フィルタ処理に用いられたロールオフ率を受信装置に通知する。送信部は、フィルタ処理された各ＯＡＭモードの送信信号をＯＡＭ多重して送信する。本実施形態の受信装置は、受信信号の非線形歪みの推定装置を有する。受信装置は、推定された非線形歪みの情報を送信装置へ通知する。送信装置の変更部は、受信装置から通知された非線形歪みの情報に基づいてロールオフ率を変更し、それに伴い帯域幅が規定を満たす範囲でシンボルレートを最大化する。このように、本実施形態では、ＯＡＭを用いた無線通信において送信信号に適用されるロールオフフィルタのロールオフ率およびシンボルレートを受信装置における非線形歪みに基づいて制御することにより、ＰＡＰＲを低減し、非線形歪みを低減しながらデータレートを向上させる。 The transmitting device of this embodiment includes an adaptive control section, a filter application section, a notification section, and a transmitting section. The adaptive control section includes a determining section and a changing section. The determining unit determines a roll-off rate of a band-limiting filter (roll-off filter) to be applied to the transmission signal of each OAM mode, based on the number of modes to be multiplexed. The filter application unit performs filter processing to apply a band-limiting filter having the determined roll-off rate to the transmission signal of each OAM mode. The notification unit notifies the receiving device of the roll-off rate used for filter processing. The transmitter multiplexes the filtered transmission signals of each OAM mode and transmits the OAM multiplexed signals. The receiving device of this embodiment includes a device for estimating nonlinear distortion of a received signal. The receiving device notifies the transmitting device of information on the estimated nonlinear distortion. The changing unit of the transmitting device changes the roll-off rate based on the nonlinear distortion information notified from the receiving device, and accordingly maximizes the symbol rate within a range where the bandwidth satisfies regulations. As described above, in this embodiment, PAPR is reduced by controlling the roll-off rate and symbol rate of the roll-off filter applied to the transmission signal in wireless communication using OAM based on the nonlinear distortion in the receiving device. , increasing data rate while reducing nonlinear distortion.
　図１は、ＯＡＭモードの信号を生成するためのＵＣＡの位相設定例を示す図である。図１（ａ）～図１（ｅ）はそれぞれ、送信装置がＯＡＭモード０～４の信号を生成するために各ＵＣＡから送信する信号の位相設定を示している。ＯＡＭモードを単に、モードとも記載する。点線の円周上に配置された丸は、ＵＣＡの各アンテナ素子を示す。同図では、アンテナ素子が８つの場合の例を示している。 FIG. 1 is a diagram showing an example of UCA phase settings for generating an OAM mode signal. FIGS. 1(a) to 1(e) respectively show phase settings of signals transmitted from each UCA in order for the transmitting device to generate signals of OAM modes 0 to 4. The OAM mode is also simply referred to as a mode. A circle placed on the dotted line circumference indicates each antenna element of the UCA. The figure shows an example in which there are eight antenna elements.
　送信装置は、ＵＣＡの各アンテナ素子に供給される信号にＤＦＴ変換行列による位相差を与えることにより、ＯＡＭモードの信号を生成する。アンテナ素子を表す丸それぞれの近傍に、そのアンテナ素子から送信する信号に与えられる位相差が示されている。具体的には、ＯＡＭモードｎの信号は、位相がｎ回転になるように各アンテナ素子に供給される位相差を設定する。例えば、図１（ｃ）に示すように、ＯＡＭモード２の信号を８素子のＵＣＡを用いて生成する場合、各アンテナ素子に与える位相差は時計回りに０度、９０度、１８０度、２７０度、０度、９０度、１８０度、２７０度である。また、ＯＡＭモード２と逆回りに各アンテナ素子に位相差を与えることで、ＯＡＭモード－２の信号が生成される。多重モード数は最大でアンテナ素子数と同じ数まで使用できるが、アンテナ素子数より少なくてもよい。 The transmitting device generates an OAM mode signal by giving a phase difference using a DFT transformation matrix to the signal supplied to each antenna element of the UCA. Near each circle representing an antenna element, the phase difference given to the signal transmitted from that antenna element is shown. Specifically, the phase difference of the OAM mode n signal supplied to each antenna element is set so that the phase is n rotations. For example, as shown in FIG. 1(c), when an OAM mode 2 signal is generated using an 8-element UCA, the phase difference given to each antenna element is 0 degrees, 90 degrees, 180 degrees, and 270 degrees in the clockwise direction. degrees, 0 degrees, 90 degrees, 180 degrees, and 270 degrees. Furthermore, by applying a phase difference to each antenna element in the opposite direction to OAM mode 2, an OAM mode-2 signal is generated. The number of multiplexed modes can be up to the same number as the number of antenna elements, but may be less than the number of antenna elements.
　受信装置が受信したＯＡＭ多重信号を分離するには、受信装置が有するＵＣＡの各アンテナ素子の位相を、送信装置の位相と逆回転方向となるように設定すればよい。 In order to separate the OAM multiplexed signal received by the receiving device, the phase of each antenna element of the UCA included in the receiving device may be set to be in the opposite rotation direction to the phase of the transmitting device.
　図２は、本発明の実施形態における無線通信システム１の構成図である。図２に示すように、無線通信システム１は、無線伝送装置１１と、無線伝送装置１２とを有する。無線伝送装置１１と無線伝送装置１２とは、対向設置される。本実施形態では、無線伝送装置１１、１２が移動しない基地局であることを想定している。ただし、このような想定は一例である。すなわち、無線伝送装置１１、１２の一方又は両方が移動してもよい。 FIG. 2 is a configuration diagram of the wireless communication system 1 in the embodiment of the present invention. As shown in FIG. 2, the wireless communication system 1 includes a wireless transmission device 11 and a wireless transmission device 12. The wireless transmission device 11 and the wireless transmission device 12 are installed facing each other. In this embodiment, it is assumed that the wireless transmission devices 11 and 12 are base stations that do not move. However, such an assumption is just an example. That is, one or both of the wireless transmission devices 11 and 12 may move.
　無線伝送装置１１及び無線伝送装置１２はそれぞれ、送信装置１００及び受信装置２００を有する。送信装置１００及び受信装置２００は、無線通信を行う無線通信装置である。送信装置１００は、ＯＡＭ多重信号の送信機能を有する。送信装置１００は、ＯＡＭモード生成装置と、ＵＣＡとを備える。送信装置１００は、１以上の異なるＯＡＭモードの信号を多重したＯＡＭ多重信号をＵＣＡから送信する。受信装置２００は、ＯＡＭ多重信号の受信機能を有する。受信装置２００は、ＯＡＭモード分離装置と、ＵＣＡとを備える。受信装置２００は、対向する送信装置１００から送信された１以上のＯＡＭモードの信号が多重されたＯＡＭ多重信号をＵＣＡにより受信し、受信したＯＡＭ多重信号から各ＯＡＭモードの信号を分離する。 The wireless transmission device 11 and the wireless transmission device 12 each have a transmitting device 100 and a receiving device 200. The transmitting device 100 and the receiving device 200 are wireless communication devices that perform wireless communication. The transmitting device 100 has an OAM multiplex signal transmitting function. Transmitting device 100 includes an OAM mode generating device and a UCA. The transmitting device 100 transmits an OAM multiplexed signal in which signals of one or more different OAM modes are multiplexed from the UCA. The receiving device 200 has an OAM multiplex signal receiving function. Receiving device 200 includes an OAM mode separation device and a UCA. Receiving device 200 receives, by UCA, an OAM multiplexed signal in which signals of one or more OAM modes transmitted from opposing transmitting device 100 are multiplexed, and separates the signals of each OAM mode from the received OAM multiplexed signal.
　まず、送信装置１００について説明する。図３は、送信装置１００の構成例を示す図である。図３に示すように、送信装置１００は、非線形歪み取得装置１１０と、送信制御装置１２０と、信号処理装置１３０と、送信パラメータ決定装置１４０と、送信パラメータ通知装置１５０と、ロールオフフィルタ適用装置１６０と、ＯＡＭモード生成装置１７０と、ＲＦ（Radio Frequency；無線周波数）チェーン１８０と、ＵＣＡ１９０とを有する。 First, the transmitting device 100 will be explained. FIG. 3 is a diagram showing a configuration example of the transmitting device 100. As shown in FIG. 3, the transmission device 100 includes a nonlinear distortion acquisition device 110, a transmission control device 120, a signal processing device 130, a transmission parameter determination device 140, a transmission parameter notification device 150, and a roll-off filter application device. 160, an OAM mode generation device 170, an RF (Radio Frequency) chain 180, and a UCA 190.
　非線形歪み取得装置１１０は、受信装置２００から通知された非線形歪み情報を取得する。非線形歪み情報は、受信信号の非線形歪みの有無を示す。非線形歪み取得装置１１０は、取得した非線形歪み情報を、送信制御装置１２０を介して送信パラメータ決定装置１４０に伝える。 The nonlinear distortion acquisition device 110 acquires the nonlinear distortion information notified from the receiving device 200. The nonlinear distortion information indicates the presence or absence of nonlinear distortion in the received signal. Nonlinear distortion acquisition device 110 transmits the acquired nonlinear distortion information to transmission parameter determination device 140 via transmission control device 120.
　送信制御装置１２０は、モード多重数、送信ＯＡＭモード、変調多値数、シンボルレート等のパラメータの値を指定する。これらのパラメータの値により、ＯＡＭ多重信号の変調方式が定まる。送信制御装置１２０は、信号処理装置１３０、送信パラメータ決定装置１４０及びＯＡＭモード生成装置１７０に、指定したそれらパラメータの値を通知する。 The transmission control device 120 specifies the values of parameters such as the number of mode multiplexing, the transmission OAM mode, the number of modulation levels, and the symbol rate. The modulation method of the OAM multiplex signal is determined by the values of these parameters. Transmission control device 120 notifies signal processing device 130, transmission parameter determination device 140, and OAM mode generation device 170 of the specified values of these parameters.
　信号処理装置１３０は、入力されたデータと、送信制御装置１２０から通知されたパラメータの値とに基づき、搬送波に乗せて送信するデジタル信号を生成する。信号処理装置１３０は、生成したデジタル信号をアナログ信号に変換する。信号処理装置１３０は、アナログ信号に変換された送信信号をロールオフフィルタ適用装置１６０へと入力する。ロールオフフィルタ適用装置１６０は、デジタル信号に対して処理を行うこともでき、アナログ信号に対して処理を行うこともできる。ロールオフフィルタ適用装置１６０の処理をデジタル処理で行う場合は、ロールオフフィルタ適用後に送信信号をアナログ信号に変換する。 The signal processing device 130 generates a digital signal to be transmitted on a carrier wave based on the input data and the parameter values notified from the transmission control device 120. The signal processing device 130 converts the generated digital signal into an analog signal. The signal processing device 130 inputs the transmission signal converted into an analog signal to the roll-off filter application device 160. The roll-off filter applying device 160 can perform processing on digital signals and can also perform processing on analog signals. When processing by the roll-off filter applying device 160 is performed by digital processing, the transmission signal is converted into an analog signal after applying the roll-off filter.
　送信パラメータ決定装置１４０は、送信制御装置１２０から通知された送信ＯＡＭモード及びモード多重数に基づきロールオフフィルタのロールオフ率を決定する。ロールオフフィルタは、各ＯＡＭモードの送信信号のフィルタ処理に用いられる。さらに、送信パラメータ決定装置１４０は、決定したロールオフ率に応じて、信号帯域幅の規定を満たす範囲でシンボルレートを最大化する。送信パラメータ決定装置１４０は、決定したロールオフ率及びシンボルレートの情報を、送信パラメータ通知装置１５０及びロールオフフィルタ適用装置１６０へと入力する。 The transmission parameter determination device 140 determines the roll-off rate of the roll-off filter based on the transmission OAM mode and mode multiplexing number notified from the transmission control device 120. The roll-off filter is used for filtering the transmission signal of each OAM mode. Further, the transmission parameter determining device 140 maximizes the symbol rate within a range that satisfies the signal bandwidth regulation according to the determined roll-off rate. Transmission parameter determination device 140 inputs information on the determined roll-off rate and symbol rate to transmission parameter notification device 150 and roll-off filter application device 160.
　送信パラメータ通知装置１５０は、送信パラメータ決定装置１４０から入力されたロールオフ率及びシンボルレートの情報を受信装置２００に通知するために適切な形に変換した後、受信装置２００に通知する。受信装置２００は、送信パラメータ通知装置１５０から通知されたロールオフ率を用いたロールオフフィルタを使用して帯域制限処理を行ってもよいし、あらかじめ定められた規定のロールオフ率のロールオフフィルタを用いてもよい。また、受信装置２００は、送信パラメータ通知装置１５０から通知されたシンボルレートを用いて受信信号をサンプリングしてもよく、あらかじめ定められた規定のシンボルレートを用いてもよい。受信装置２００が規定のロールオフ率及び規定のシンボルレートを使用する場合、送信装置１００は、送信パラメータ通知装置１５０を有してもよく、有さなくてもよい。 The transmission parameter notification device 150 converts the roll-off rate and symbol rate information input from the transmission parameter determination device 140 into a format suitable for notification to the reception device 200, and then notifies the reception device 200. The receiving device 200 may perform the band limiting process using a roll-off filter using the roll-off rate notified from the transmission parameter notification device 150, or may perform band-limiting processing using a roll-off filter using a roll-off rate determined in advance. may also be used. Further, receiving device 200 may sample the received signal using the symbol rate notified from transmission parameter notification device 150, or may use a predetermined prescribed symbol rate. When receiving device 200 uses a specified roll-off rate and a specified symbol rate, transmitting device 100 may or may not include transmission parameter notification device 150.
　ロールオフフィルタ適用装置１６０は、信号処理装置１３０から入力された送信信号を、送信パラメータ決定装置１４０から通知されたシンボルレートの信号に変換する。ロールオフフィルタ適用装置１６０は、変換後の信号に、送信パラメータ決定装置１４０から通知されたロールオフ率を用いたロールオフフィルタ処理を適用する。ロールオフフィルタ適用装置１６０は、フィルタ処理後の信号をＯＡＭモード生成装置１７０へと入力する。 The roll-off filter application device 160 converts the transmission signal input from the signal processing device 130 into a signal at the symbol rate notified from the transmission parameter determination device 140. Roll-off filter application device 160 applies roll-off filter processing to the converted signal using the roll-off rate notified from transmission parameter determination device 140. Roll-off filter application device 160 inputs the filtered signal to OAM mode generation device 170.
　ＯＡＭモード生成装置１７０は、ＤＦＴ変換行列を付与するアナログ回路もしくはデジタル信号処理装置である。ＯＡＭモード生成装置１７０は、ロールオフフィルタ適用装置１６０から入力された信号にＤＦＴ変換行列を付与することにより、送信制御装置１２０から指定されたモードの送信信号を生成する。ＯＡＭモード生成装置１７０は、各ＯＡＭモードの送信信号をデジタル処理で生成した後、周波数変換を行ってもよい。あるいは、ＯＡＭモード生成装置１７０は、周波数変換を行った後にアナログ回路で各ＯＡＭモードの送信信号を生成してもよい。またあるいは、ＯＡＭモード生成装置１７０は、アナログ回路でＯＡＭモードの送信信号を生成した後に周波数変換を行ってもよい。ＯＡＭモード生成装置１７０は、生成された各ＯＡＭモードの送信信号を多重してＲＦチェーン１８０に入力する。 The OAM mode generation device 170 is an analog circuit or a digital signal processing device that provides a DFT transformation matrix. OAM mode generation device 170 generates a transmission signal in a mode specified by transmission control device 120 by adding a DFT transformation matrix to the signal input from roll-off filter application device 160. The OAM mode generation device 170 may perform frequency conversion after generating the transmission signal of each OAM mode by digital processing. Alternatively, the OAM mode generation device 170 may generate a transmission signal for each OAM mode using an analog circuit after performing frequency conversion. Alternatively, the OAM mode generation device 170 may perform frequency conversion after generating an OAM mode transmission signal using an analog circuit. OAM mode generation device 170 multiplexes the generated transmission signals of each OAM mode and inputs the multiplexed signals to RF chain 180.
　ＲＦチェーン１８０は、ＯＡＭモード生成装置１７０から入力された送信信号を周波数変換し、増幅した後、ＵＣＡ１９０に入力する。ＵＣＡ１９０は、Ｍ個のアンテナ素子が円形上に配置されたアンテナである。ＵＣＡ１９０は、各ＯＡＭモードの送信信号を多重したＯＡＭ多重信号を送受信する。 The RF chain 180 frequency-converts and amplifies the transmission signal input from the OAM mode generation device 170, and then inputs the signal to the UCA 190. The UCA 190 is an antenna in which M antenna elements are arranged in a circle. The UCA 190 transmits and receives an OAM multiplex signal obtained by multiplexing transmission signals of each OAM mode.
　図４は、送信装置１００におけるＯＡＭモード生成装置１７０、ＲＦチェーン１８０及びＵＣＡ１９０の接続構成例を示す図である。ＵＣＡ１９０は、Ｍ個のアンテナ素子１９１が円形上に配置されたアンテナである。Ｍ個のアンテナ素子１９１をそれぞれ、アンテナ素子１９１－１～１９１－Ｍと記載する。 FIG. 4 is a diagram showing an example of a connection configuration of the OAM mode generation device 170, RF chain 180, and UCA 190 in the transmitting device 100. The UCA 190 is an antenna in which M antenna elements 191 are arranged in a circle. The M antenna elements 191 are respectively referred to as antenna elements 191-1 to 191-M.
　ＯＡＭモード生成装置１７０は、出力ポート＃１～＃Ｍを有する。ＯＡＭモード生成装置１７０は、モード０～Ｎの各信号に、モードに応じたＤＦＴ変換行列を付与し、アンテナ素子１９１－１～１９１－Ｍそれぞれから送信する送信信号を生成する。ＯＡＭモード生成装置１７０は、アンテナ素子１９１－ｍ（ｍは１以上Ｍ以下の整数）ごとに、アンテナ素子１９１－ｍから送信する各モードの信号を多重し、多重した信号＃ｍを出力ポート＃ｍから出力する。 The OAM mode generation device 170 has output ports #1 to #M. OAM mode generation device 170 adds a DFT transformation matrix according to the mode to each signal of modes 0 to N, and generates a transmission signal to be transmitted from each of antenna elements 191-1 to 191-M. The OAM mode generation device 170 multiplexes the signals of each mode transmitted from the antenna element 191-m for each antenna element 191-m (m is an integer between 1 and M), and outputs the multiplexed signal #m to the output port #. Output from m.
　ＲＦチェーン１８０は、ＲＦチェーン＃１～＃Ｍを有する。ＲＦチェーン＃１～＃Ｍはそれぞれ、ＯＡＭモード生成装置１７０から信号＃１～＃Ｍを入力する。ＲＦチェーン＃ｍは、信号＃ｍの周波数を変換し、増幅した後、アンテナ素子１９１－ｍに出力する。ＵＣＡ１９０は、ＲＦチェーン１８０から入力された信号＃１～＃Ｍをそれぞれ、アンテナ素子１９１－１～１９１－Ｍから電波として送信する。 The RF chain 180 has RF chains #1 to #M. RF chains #1 to #M each receive signals #1 to #M from OAM mode generation device 170. RF chain #m converts the frequency of signal #m, amplifies it, and then outputs it to antenna element 191-m. UCA 190 transmits signals #1 to #M input from RF chain 180 as radio waves from antenna elements 191-1 to 191-M, respectively.
　図５は、送信制御装置１２０の機能構成例を示す図である。送信制御装置１２０は、通信性能取得部１２１と、送信ＯＡＭモード決定部１２２と、多重数決定部１２３と、送信信号パラメータ決定部１２４とを備える。 FIG. 5 is a diagram showing an example of the functional configuration of the transmission control device 120. The transmission control device 120 includes a communication performance acquisition section 121, a transmission OAM mode determination section 122, a multiplexing number determination section 123, and a transmission signal parameter determination section 124.
　通信性能取得部１２１は、通信特性情報を取得する装置である。通信特性情報は、送信装置１００と受信装置２００との間の通信の特性を示す。通信特性情報が示す特性は、例えば、送受信間距離、受信信号電力対干渉雑音電力比（Signal-to-interference and noise ratio：ＳＩＮＲ）、モード間干渉などである。送受信間距離は、送信装置１００と受信装置２００との間の距離である。 The communication performance acquisition unit 121 is a device that acquires communication characteristic information. Communication characteristic information indicates characteristics of communication between transmitting device 100 and receiving device 200. The characteristics indicated by the communication characteristic information include, for example, the distance between transmitter and receiver, the received signal power to interference and noise ratio (SINR), and the interference between modes. The transmitting/receiving distance is the distance between the transmitting device 100 and the receiving device 200.
　送信ＯＡＭモード決定部１２２は、通信特性情報に基づいて送信ＯＡＭモードを決定し、決定したＯＡＭモードの情報を送信パラメータ決定装置１４０へと入力する。多重数決定部１２３は、通信特性情報に基づいて、例えば伝送容量が最大となるモード多重数及び変調多値数を決定し、決定したモード多重数及び変調多値数の情報を送信パラメータ決定装置１４０へと入力する。送信信号パラメータ決定部１２４は、通信特性情報に基づいて、符号化率等の送信信号パラメータの値を決定し、決定した送信信号パラメータの値の情報を送信パラメータ決定装置１４０へと入力する。送信ＯＡＭモード決定部１２２、多重数決定部１２３及び送信信号パラメータ決定部１２４は、例えば、通信特性情報として送受信間距離及び受信ＳＩＮＲを用いる。 The transmission OAM mode determination unit 122 determines the transmission OAM mode based on the communication characteristic information, and inputs information on the determined OAM mode to the transmission parameter determination device 140. The multiplexing number determining unit 123 determines, for example, the mode multiplexing number and modulation level number that maximizes the transmission capacity based on the communication characteristic information, and transmits information on the determined mode multiplexing number and modulation level number to the transmission parameter determining device. 140. The transmission signal parameter determination unit 124 determines the value of a transmission signal parameter such as a coding rate based on the communication characteristic information, and inputs information on the determined value of the transmission signal parameter to the transmission parameter determination device 140. The transmission OAM mode determination section 122, the multiplex number determination section 123, and the transmission signal parameter determination section 124 use, for example, the distance between transmission and reception and the reception SINR as communication characteristic information.
　図５では一例として、通信性能取得部１２１、送信ＯＡＭモード決定部１２２、多重数決定部１２３の順に処理が行われるものとしたが、順番が入れ変わってもよい。 In FIG. 5, as an example, processing is performed in the order of the communication performance acquisition unit 121, the transmission OAM mode determination unit 122, and the multiplex number determination unit 123, but the order may be changed.
　図６は、送信パラメータ決定装置１４０の機能構成例を示す図である。送信パラメータ決定装置１４０は、送信制御装置１２０から入力されたパラメータの値のうち少なくとも一部に基づき、ＰＡＰＲを低減するようにロールオフフィルタのロールオフ率を決定する。送信パラメータ決定装置１４０は、通信パラメータ取得部１４１と、ＰＡＰＲ情報保持部１４２と、ロールオフ率決定部１４３と、シンボルレート決定部１４４とを備える。 FIG. 6 is a diagram showing an example of the functional configuration of the transmission parameter determining device 140. Transmission parameter determination device 140 determines the roll-off rate of the roll-off filter based on at least a portion of the parameter values input from transmission control device 120 so as to reduce PAPR. The transmission parameter determination device 140 includes a communication parameter acquisition section 141, a PAPR information holding section 142, a roll-off rate determination section 143, and a symbol rate determination section 144.
　通信パラメータ取得部１４１は、送信制御装置１２０から通知された変調多値数、モード多重数及び送信ＯＡＭモード等のパラメータの情報を取得し、これらのパラメータの情報をロールオフ率決定部１４３に通知する。 The communication parameter acquisition unit 141 acquires information on parameters such as the number of modulation levels, the number of mode multiplexing, and the transmission OAM mode notified from the transmission control device 120, and notifies the roll-off rate determination unit 143 of the information on these parameters. do.
　ＰＡＰＲ情報保持部１４２は、ロールオフ率と、モード多重数と、ＯＡＭモードと、ＰＡＰＲとの関係を示すＰＡＰＲ情報を保持する記憶媒体である。ＰＡＰＲ情報保持部１４２は、変調方式毎にＰＡＰＲ情報を保持してもよい。例えば、ロールオフ率と、モード多重数と、ＯＡＭモードと、ＰＡＰＲとの関係を計算して生成したＰＡＰＲ情報を予めＰＡＰＲ情報保持部１４２に記憶させておいてもよい。あるいは、ＰＡＰＲ情報保持部１４２は、上記の関係を逐次計算し、ＰＡＰＲ情報として記憶してもよい。 The PAPR information holding unit 142 is a storage medium that holds PAPR information indicating the relationship between the roll-off rate, the mode multiplexing number, the OAM mode, and the PAPR. The PAPR information holding unit 142 may hold PAPR information for each modulation method. For example, PAPR information generated by calculating the relationship between the roll-off rate, the mode multiplexing number, the OAM mode, and the PAPR may be stored in the PAPR information holding unit 142 in advance. Alternatively, the PAPR information holding unit 142 may sequentially calculate the above relationship and store it as PAPR information.
　ロールオフ率決定部１４３は、通信パラメータ取得部１４１から通知されたモード多重数及び送信ＯＡＭモードの情報と、ＰＡＰＲ情報保持部１４２に記憶されている情報とに基づいてロールオフ率を決定する。具体的には、ロールオフ率決定部１４３は、後述する図１４に記載のアルゴリズムを実行してロールオフ率を決定する。シンボルレート決定部１４４は、ロールオフ率決定部１４３が決定したロールオフ率に基づきシンボルレートを決定する。 The roll-off rate determining unit 143 determines the roll-off rate based on the information on the mode multiplexing number and transmission OAM mode notified from the communication parameter acquiring unit 141 and the information stored in the PAPR information holding unit 142. Specifically, the roll-off rate determination unit 143 executes an algorithm described in FIG. 14, which will be described later, to determine the roll-off rate. The symbol rate determining unit 144 determines the symbol rate based on the roll-off rate determined by the roll-off rate determining unit 143.
　図７は、１６ＱＡＭ（Quadrature Amplitude Modulation：直交位相振幅変調）信号の場合のロールオフ率、モード多重数、ＯＡＭモード及びＰＡＰＲの関係を表す図である。凡例に示す［］の中の各値は、ＯＡＭモードの種類を表す。［］の中の数値の個数は、モード多重数を表す。例えば、［０　１　－１］は、ＯＡＭモード０、１、－１、モード多重数３を表す。ＰＡＰＲ情報保持部１４２は、例えば、変調方式の情報と対応付けて、図７に示す関係を表すＰＡＰＲ情報を記憶する。 FIG. 7 is a diagram showing the relationship among the roll-off rate, mode multiplexing number, OAM mode, and PAPR in the case of a 16QAM (Quadrature Amplitude Modulation) signal. Each value in [ ] shown in the legend represents the type of OAM mode. The number of numbers in [ ] represents the number of mode multiplexing. For example, [0 1 -1] represents OAM modes 0, 1, -1 and mode multiplexing number 3. The PAPR information holding unit 142 stores, for example, PAPR information representing the relationship shown in FIG. 7 in association with modulation method information.
　図８は、ルックアップテーブル（ＬＵＴ）の例を示す図である。ＰＡＰＲ情報保持部１４２は、図７に示す関係を記憶する代わりに、変調方式の情報と対応付けて、図８に示すルックアップテーブルをＰＡＰＲ情報として記憶してもよい。ルックアップテーブルは、モード多重数と、ＰＡＰＲを最小とするロールオフ率とを対応付けたデータである。図７に示すグラフにおける符号Ｌは、多重数毎にＰＡＰＲが最小となる点を結んだ点である。この符号Ｌ上の点に基づいて、モード多重数と、ＰＡＰＲを最小とするロールオフ率との関係が得られる。なお、ルックアップテーブルは、事前のシミュレーション評価結果を用いて作成されてもよいし、実測値を基に作成されてもよい。 FIG. 8 is a diagram showing an example of a lookup table (LUT). Instead of storing the relationship shown in FIG. 7, the PAPR information holding unit 142 may store the lookup table shown in FIG. 8 as PAPR information in association with the modulation method information. The lookup table is data that associates the mode multiplexing number with the roll-off rate that minimizes the PAPR. The symbol L in the graph shown in FIG. 7 is a point connecting points where PAPR is minimum for each multiplex number. Based on this point on the code L, the relationship between the mode multiplexing number and the roll-off rate that minimizes the PAPR can be obtained. Note that the lookup table may be created using preliminary simulation evaluation results, or may be created based on actual measured values.
　次に、受信装置２００について説明する。図９は、受信装置２００の機能構成例を示す図である。受信装置２００は、ＵＣＡ２１０と、ＲＦチェーン２２０と、ＯＡＭモード分離装置２３０と、受信信号処理装置２４０と、ロールオフ率取得装置２５０と、非線形歪み推定装置２６０と、復調器２７０と、非線形歪み通知装置２８０とを有する。 Next, the receiving device 200 will be explained. FIG. 9 is a diagram showing an example of the functional configuration of the receiving device 200. The receiving device 200 includes a UCA 210, an RF chain 220, an OAM mode separation device 230, a received signal processing device 240, a roll-off rate acquisition device 250, a nonlinear distortion estimation device 260, a demodulator 270, and a nonlinear distortion notification device. device 280.
　ＵＣＡ２１０は、送信装置１００から送信された電波を受信し、ＲＦチェーン２２０へと入力する。ＲＦチェーン２２０は、ＵＣＡ２１０から入力された信号の周波数変換及び増幅などを行い、ＯＡＭモード分離装置２３０へと入力する。ＯＡＭモード分離装置２３０は、ＩＤＦＴ変換行列を付与するアナログ回路もしくはデジタル信号処理装置である。ＯＡＭモード分離装置２３０は、ＲＦチェーン２２０から入力された信号を各モードの信号へと分離し、分離した信号を受信信号処理装置２４０へと入力する。 The UCA 210 receives radio waves transmitted from the transmitting device 100 and inputs them to the RF chain 220. The RF chain 220 performs frequency conversion and amplification of the signal input from the UCA 210 and inputs the signal to the OAM mode separation device 230 . OAM mode separator 230 is an analog circuit or digital signal processing device that provides an IDFT transformation matrix. OAM mode separation device 230 separates the signal input from RF chain 220 into signals of each mode, and inputs the separated signals to received signal processing device 240 .
　受信信号処理装置２４０は、ロールオフ率取得装置２５０から通知された、あるいは、予め定められたシンボルレートに基づいてＯＡＭモード分離装置２３０から入力された信号をサンプリングする。さらに、受信信号処理装置２４０は、ロールオフ率取得装置２５０から通知された、又は、予め定められたロールオフ率に基づいて、サンプリングされた信号に帯域制限フィルタ処理を行うか、アナログフィルタを用いて帯域制限フィルタ処理を行う。受信信号処理装置２４０は、フィルタ処理が施された信号を非線形歪み推定装置２６０へと入力する。ロールオフ率取得装置２５０は、送信装置１００の送信パラメータ通知装置１５０から送信されたロールオフ率及びシンボルレートの情報を、受信信号処理装置２４０に通知する。 The received signal processing device 240 samples the signal notified from the roll-off rate acquisition device 250 or input from the OAM mode separation device 230 based on a predetermined symbol rate. Further, the received signal processing device 240 performs band-limiting filter processing on the sampled signal based on the roll-off rate notified from the roll-off rate acquisition device 250 or based on a predetermined roll-off rate, or uses an analog filter. Performs band-limiting filter processing. Received signal processing device 240 inputs the filtered signal to nonlinear distortion estimation device 260. The roll-off rate acquisition device 250 notifies the received signal processing device 240 of the roll-off rate and symbol rate information transmitted from the transmission parameter notification device 150 of the transmitting device 100.
　非線形歪み推定装置２６０は、受信信号処理装置２４０から入力された信号のコンスタレーションに基づいて非線形歪みを推定する。非線形歪み推定装置２６０は、受信信号処理装置２４０から入力された信号をそのまま復調器２７０へと入力する。復調器２７０は、非線形歪み推定装置２６０から入力された信号を復調する。非線形歪み通知装置２８０は、非線形歪み推定装置２６０から通知された非線形歪みの有無を示す非線形歪み情報を適切な形に変換し、無線もしくはバックボーン回線を通して送信装置１００へ出力する。 The nonlinear distortion estimating device 260 estimates nonlinear distortion based on the constellation of the signal input from the received signal processing device 240. Nonlinear distortion estimating device 260 inputs the signal input from received signal processing device 240 as is to demodulator 270 . Demodulator 270 demodulates the signal input from nonlinear distortion estimation device 260. Nonlinear distortion notification device 280 converts the nonlinear distortion information indicating the presence or absence of nonlinear distortion notified from nonlinear distortion estimation device 260 into an appropriate format, and outputs it to transmitting device 100 via radio or a backbone line.
　図１０は、非線形歪み推定装置２６０の構成例を示す。非線形歪み推定装置２６０は、コンスタレーション抽出部２６１と、ＥＶＭ（Error Vector Magnitude：エラーベクトル振幅）算出部２６２と、ＥＶＭ比較部２６３とを備える。コンスタレーション抽出部２６１は、受信信号の信号点の電圧に基づき、信号点を分類する。ＥＶＭ算出部２６２は、それぞれの信号点のＥＶＭを算出する。ＥＶＭ比較部２６３は、それぞれの信号点のＥＶＭを比較し、非線形歪み発生の有無を判定する。 FIG. 10 shows a configuration example of the nonlinear distortion estimation device 260. The nonlinear distortion estimation device 260 includes a constellation extraction section 261, an EVM (Error Vector Magnitude) calculation section 262, and an EVM comparison section 263. The constellation extraction unit 261 classifies signal points based on the voltage of the signal points of the received signal. The EVM calculation unit 262 calculates the EVM of each signal point. The EVM comparison unit 263 compares the EVM of each signal point and determines whether nonlinear distortion occurs.
　続いて、無線通信システム１の処理を説明する。図１１は、無線伝送装置１１の送信装置１００と無線伝送装置１２の受信装置２００との処理を示すシーケンス図である。まず、送信装置１００の送信パラメータ決定装置１４０は、ＰＡＰＲ情報保持部１４２に記憶されているルックアップテーブルからＰＡＰＲを最小とするロールオフ率を読み出して、初期値とする（ステップＳ１１）。 Next, the processing of the wireless communication system 1 will be explained. FIG. 11 is a sequence diagram showing processing by the transmitting device 100 of the wireless transmission device 11 and the receiving device 200 of the wireless transmission device 12. First, the transmission parameter determining device 140 of the transmitting device 100 reads the roll-off rate that minimizes the PAPR from the lookup table stored in the PAPR information holding unit 142, and sets it as an initial value (step S11).
　具体的には、送信装置１００の送信制御装置１２０は、モード多重数、送信ＯＡＭモード、変調多値数、シンボルレート等のパラメータの値を決定する。ロールオフ率決定部１４３は、送信制御装置１２０から通知されたパラメータの値により特定される符号化方式の情報に対応してＰＡＰＲ情報保持部１４２に記憶されているルックアップテーブルから、モード多重数を検索条件に用いてロールオフ率を読み出す。なお、ルックアップテーブルには、モード多重数の情報に代えて、モード多重数とＯＡＭモードとの組み合わせの情報を用いてもよい。この場合、ロールオフ率決定部１４３は、ルックアップテーブルから、モード多重数及び送信ＯＡＭモードを検索条件に用いてロールオフ率を読み出す。さらに、シンボルレート決定部１４４は、読み出されたロールオフ率に対応したシンボルレートを決定する。 Specifically, the transmission control device 120 of the transmitting device 100 determines the values of parameters such as the number of mode multiplexing, the transmission OAM mode, the number of modulation levels, and the symbol rate. The roll-off rate determination unit 143 determines the mode multiplexing number from the lookup table stored in the PAPR information storage unit 142 corresponding to the encoding method information specified by the value of the parameter notified from the transmission control device 120. Read out the roll-off rate using as the search condition. Note that instead of the information on the number of modes to be multiplexed, information on the combination of the number of modes to be multiplexed and the OAM mode may be used in the lookup table. In this case, the roll-off rate determining unit 143 reads the roll-off rate from the lookup table using the mode multiplexing number and the transmission OAM mode as search conditions. Further, the symbol rate determining unit 144 determines a symbol rate corresponding to the read roll-off rate.
　送信装置１００は、送信制御装置１２０が決定したパラメータの値と、送信パラメータ決定装置１４０が決定したロールオフ率及びシンボルレートとを用いて生成したＯＡＭ多重信号を送信する（ステップＳ１２）。 The transmitting device 100 transmits an OAM multiplex signal generated using the parameter values determined by the transmission control device 120 and the roll-off rate and symbol rate determined by the transmission parameter determining device 140 (step S12).
　受信装置２００は、送信装置１００が送信したＯＡＭ多重信号を受信する。受信装置２００の非線形歪み推定装置２６０は、受信した信号に基づいて非線形歪みの有無を推定する（ステップＳ１３）。受信装置２００の非線形歪み通知装置２８０は、ステップＳ１３における推定結果を示す非線形歪み情報を送信装置１００に通知する（ステップＳ１４）。送信装置１００の非線形歪み取得装置１１０は、受信装置２００から通知された非線形歪み情報を取得する。 The receiving device 200 receives the OAM multiplex signal transmitted by the transmitting device 100. The nonlinear distortion estimating device 260 of the receiving device 200 estimates the presence or absence of nonlinear distortion based on the received signal (step S13). The nonlinear distortion notification device 280 of the receiving device 200 notifies the transmitting device 100 of nonlinear distortion information indicating the estimation result in step S13 (step S14). The nonlinear distortion acquisition device 110 of the transmitting device 100 acquires the nonlinear distortion information notified from the receiving device 200.
　送信装置１００の送信制御装置１２０は、非線形歪み取得装置１１０が取得した非線形歪み情報を送信パラメータ決定装置１４０に入力する。ロールオフ率決定部１４３は、非線形歪み情報が示す非線形歪みの有無に応じてロールオフ率を変更する。さらに、シンボルレート決定部１４４は、変更後のロールオフ率に基づいてシンボルレートを変更する（ステップＳ１５）。 The transmission control device 120 of the transmitting device 100 inputs the nonlinear distortion information acquired by the nonlinear distortion acquisition device 110 to the transmission parameter determination device 140. The roll-off rate determining unit 143 changes the roll-off rate depending on the presence or absence of non-linear distortion indicated by the non-linear distortion information. Further, the symbol rate determining unit 144 changes the symbol rate based on the changed roll-off rate (step S15).
　送信装置１００は、変更後のロールオフ率及びシンボルレートを用いてＯＡＭ多重信号を生成し、送信する（ステップＳ１６）。受信装置２００のＵＣＡ２１０は、送信装置１００から送信されたＯＡＭ多重信号を受信する。送信装置１００の送信パラメータ通知装置１５０は、ステップＳ１６と並行して、ロールオフ率及びシンボルレートの情報を受信装置２００に通知する（ステップＳ１７）。受信装置２００のロールオフ率取得装置２５０は、送信装置１００から送信されたロールオフ率及びシンボルレートの情報を受信し、受信信号処理装置２４０へと出力する。 The transmitting device 100 generates and transmits an OAM multiplex signal using the changed roll-off rate and symbol rate (step S16). UCA 210 of receiving device 200 receives the OAM multiplex signal transmitted from transmitting device 100. Transmission parameter notification device 150 of transmitting device 100 notifies information on the roll-off rate and symbol rate to receiving device 200 in parallel with step S16 (step S17). Roll-off rate acquisition device 250 of receiving device 200 receives information on the roll-off rate and symbol rate transmitted from transmitting device 100, and outputs it to received signal processing device 240.
　受信装置２００は、受信したＯＡＭ多重信号に、通知されたロールオフ率及びシンボルレートを用いて受信処理を行う。受信装置２００の復調器２７０は、受信信号を復調する（ステップＳ１８）。ステップＳ１８と並行して、受信装置２００は、ステップＳ１３からの処理を繰り返し、受信したＯＡＭ多重信号の非線形歪みの有無を推定し、送信装置１００へ再度通知してもよい。 The receiving device 200 performs reception processing on the received OAM multiplex signal using the notified roll-off rate and symbol rate. The demodulator 270 of the receiving device 200 demodulates the received signal (step S18). In parallel with step S18, the receiving device 200 may repeat the processing from step S13, estimate the presence or absence of nonlinear distortion in the received OAM multiplexed signal, and notify the transmitting device 100 again.
　無線通信システム１は、ステップＳ１２～ステップＳ１８の処理を、定期的にもしくは信号フレームの送信ごとに行う。これにより、無線通信システム１は、ロールオフ率及びシンボルレートを非線形歪み量に応じて適応的に制御する。 The wireless communication system 1 performs the processes of steps S12 to S18 periodically or every time a signal frame is transmitted. Thereby, the wireless communication system 1 adaptively controls the roll-off rate and symbol rate according to the amount of nonlinear distortion.
　続いて、図１１のステップＳ１３における非線形歪み推定装置２６０の詳細な処理を説明する。図１２は、非線形歪みを受けた１６ＱＡＭ信号のコンスタレーションの一例を示す。図１２に示すように、送信ＲＦで受けた非線形歪みは電圧の高い外側の信号点Ｐ１～Ｐ４に与える影響が大きい。そこで、非線形歪み推定装置２６０は、外側の信号点Ｐ１～Ｐ４の平均ＥＶＭと内側の信号点Ｑ１～Ｑ４の平均ＥＶＭとを比較することで非線形歪みの有無を推定する。平均ＥＶＭは、平均２乗誤差を信号の平均電力で正規化したものである。信号点Ｐ１～Ｐ４を総称して信号点Ｐと記載し、信号点Ｑ１～Ｑ４を総称して信号点Ｑと記載する。 Next, detailed processing of the nonlinear distortion estimating device 260 in step S13 of FIG. 11 will be described. FIG. 12 shows an example of a constellation of a 16QAM signal subjected to nonlinear distortion. As shown in FIG. 12, the nonlinear distortion received by the transmission RF has a large effect on the outer signal points P1 to P4 where the voltage is high. Therefore, the nonlinear distortion estimation device 260 estimates the presence or absence of nonlinear distortion by comparing the average EVM of the outer signal points P1 to P4 and the average EVM of the inner signal points Q1 to Q4. The average EVM is the mean squared error normalized by the average power of the signal. Signal points P1 to P4 are collectively referred to as signal point P, and signal points Q1 to Q4 are collectively referred to as signal point Q.
　図１３は、非線形歪み推定装置２６０において非線形歪み量を推定するアルゴリズムを示すフロー図である。非線形歪み推定装置２６０のコンスタレーション抽出部２６１は、受信信号のコンスタレーションを正規化し、外側の信号点Ｐと内側の信号点Ｑとに分類する（ステップＳ３１）。ｎ個目（ｎは１以上の整数）の複素受信信号をｚ［ｎ］＝ｘ［ｎ］＋ｊｙ［ｎ］とする。ｊは複素数を表す。コンスタレーション抽出部２６１は、図１２に示すように、｜ｘ［ｎ］｜＞Ａかつ｜ｙ［ｎ］｜＞Ａの信号点ｎを外側の信号点Ｐとする。信号点Ｐは、ｘ［ｎ］の正負及びｙ［ｎ］の正負の組み合わせによって、信号点Ｐ１、Ｐ２、Ｐ３、Ｐ４に分類される。また、コンスタレーション抽出部２６１は、図１２に示すように、｜ｘ［ｎ］｜＜Ａかつ｜ｙ［ｎ］｜＜Ａの信号点ｎを内側の信号点Ｑとする。信号点Ｑも、ｘ［ｎ］の正負及びｙ［ｎ］の正負の組み合わせによって、信号点Ｑ１、Ｑ２、Ｑ３、Ｑ４に分類される。 FIG. 13 is a flow diagram showing an algorithm for estimating the amount of nonlinear distortion in the nonlinear distortion estimation device 260. The constellation extraction unit 261 of the nonlinear distortion estimating device 260 normalizes the constellation of the received signal and classifies it into outer signal points P and inner signal points Q (step S31). Let z[n]=x[n]+jy[n] be the n-th (n is an integer greater than or equal to 1) complex received signal. j represents a complex number. As shown in FIG. 12, the constellation extraction unit 261 sets the signal point n of |x[n]|>A and |y[n]|>A as the outer signal point P. The signal point P is classified into signal points P1, P2, P3, and P4 depending on the combination of the positive/negative of x[n] and the positive/negative of y[n]. Further, as shown in FIG. 12, the constellation extraction unit 261 sets the signal point n of |x[n]|<A and |y[n]|<A as the inner signal point Q. The signal point Q is also classified into signal points Q1, Q2, Q3, and Q4 depending on the combination of the positive/negative of x[n] and the positive/negative of y[n].
　非線形歪み推定装置２６０のＥＶＭ算出部２６２は、外側の信号点Ｐの平均ＥＶＭ及び内側の信号点Ｑの平均ＥＶＭを求める（ステップＳ３２）。ＥＶＭ算出部２６２は、例えば、ＯＡＭ多重信号のプリアンブルを用いてあらかじめ送信装置１００及び受信装置２００間で共有した本来の信号点を基準とし、各信号点の基準からの平均誤差を平均ＥＶＭとして算出する。信号点Ｐ１、Ｐ２、Ｐ３、Ｐ４、Ｑ１、Ｑ２、Ｑ３、Ｑ４の分類毎に基準は異なる。あるいは、ＥＶＭ算出部２６２は、分類毎に信号点の電圧の平均値を基準とし、その基準から平均誤差を平均ＥＶＭとして簡易に推定してもよい。 The EVM calculation unit 262 of the nonlinear distortion estimation device 260 calculates the average EVM of the outer signal point P and the average EVM of the inner signal point Q (step S32). For example, the EVM calculation unit 262 calculates the average error from the standard of each signal point as the average EVM using the original signal point shared between the transmitting device 100 and the receiving device 200 in advance using the preamble of the OAM multiplexed signal as a standard. do. The criteria differ for each classification of signal points P1, P2, P3, P4, Q1, Q2, Q3, and Q4. Alternatively, the EVM calculation unit 262 may use the average value of the voltage of the signal point for each classification as a reference, and simply estimate the average error as the average EVM from that reference.
　非線形歪み推定装置２６０のＥＶＭ比較部２６３は、外側の信号点Ｐの平均ＥＶＭ及び内側の信号点Ｑの平均ＥＶＭを比較し、非線形歪みが発生しているか否かを判断する（ステップＳ３３）。具体的には、ＥＶＭ比較部２６３は、以下の式（１）を満たすと判断した場合、非線形歪みが発生しているとみなす。 The EVM comparison unit 263 of the nonlinear distortion estimating device 260 compares the average EVM of the outer signal point P and the average EVM of the inner signal point Q, and determines whether nonlinear distortion has occurred (step S33). Specifically, if the EVM comparison unit 263 determines that the following equation (1) is satisfied, it considers that nonlinear distortion has occurred.
（外側の信号点Ｐの平均ＥＶＭ）－（内側の信号点Ｑの平均ＥＶＭ）＞α　　　…（１） (Average EVM of outer signal point P) - (Average EVM of inner signal point Q) > α ... (1)
　ＥＶＭ比較部２６３は、非線形歪みの発生を示す非線形歪み情報を、非線形歪み通知装置２８０を通して送信装置１００へ通知する。 The EVM comparison unit 263 notifies the transmitting device 100 of nonlinear distortion information indicating the occurrence of nonlinear distortion through the nonlinear distortion notification device 280.
　一方、ＥＶＭ比較部２６３は、以下の式（２）を満たすと判断した場合、非線形歪みが発生していないとみなす。 On the other hand, if the EVM comparison unit 263 determines that the following equation (2) is satisfied, it is considered that nonlinear distortion has not occurred.
（外側の信号点Ｐの平均ＥＶＭ）－（内側の信号点Ｑの平均ＥＶＭ）＜α　　　…（２） (Average EVM of outer signal point P) - (Average EVM of inner signal point Q) <α...(2)
　ＥＶＭ比較部２６３は、非線形歪みが発生していないことを示す非線形歪み情報を、非線形歪み通知装置２８０を通して送信装置１００へ通知する。非線形歪み通知装置２８０は、ＥＶＭ比較部２６３から入力された非線形歪み情報を、無線もしくはバックボーン回線を通して送信装置１００へ通知する（図１１のステップＳ１４）。 The EVM comparison unit 263 notifies the transmitting device 100 of nonlinear distortion information indicating that nonlinear distortion has not occurred through the nonlinear distortion notification device 280. The nonlinear distortion notification device 280 notifies the transmission device 100 of the nonlinear distortion information input from the EVM comparison unit 263 via wireless or a backbone line (step S14 in FIG. 11).
　なお、αはマージンである。αは、例えば１ｄＢ等の値であるが、任意に設計してよい。受信装置２００の非線形歪み通知装置２８０は、外側の信号点Ｐの平均ＥＶＭ及び内側の信号点Ｑの平均ＥＶＭ、あるいは、外側の信号点Ｐの平均ＥＶＭと内側の信号点Ｑの平均ＥＶＭとの差分を設定した非線形歪み情報を送信装置１００に通知してもよい。送信装置１００の送信パラメータ決定装置１４０は、受信した非線形歪み情報に基づいて外側の信号点Ｐの平均ＥＶＭと内側の信号点Ｑの平均ＥＶＭとの差分の情報を取得し、取得した差分がαを超えるか否かにより非線形歪みの有無を判断してもよい。 Note that α is the margin. α is, for example, a value of 1 dB, but may be arbitrarily designed. The nonlinear distortion notification device 280 of the receiving device 200 calculates the average EVM of the outer signal point P and the average EVM of the inner signal point Q, or the average EVM of the outer signal point P and the average EVM of the inner signal point Q. The transmitting device 100 may be notified of the nonlinear distortion information in which the difference is set. The transmission parameter determining device 140 of the transmitting device 100 acquires information on the difference between the average EVM of the outer signal point P and the average EVM of the inner signal point Q based on the received nonlinear distortion information, and the obtained difference is α The presence or absence of nonlinear distortion may be determined based on whether or not it exceeds .
　続いて、図１１のステップＳ１１及びＳ１５において、送信装置１００の送信パラメータ決定装置１４０が実行する処理の詳細を説明する。図１４は、送信装置１００の送信パラメータ決定装置１４０が実行するロールオフ率及びシンボルレートの決定アルゴリズムを示すフロー図である。図１４に示すアルゴリズムは、データレート向上を目的としてロールオフ率βとシンボルレートρを決定する。本アルゴリズムでは、受信装置２００が推定した非線形歪み量の有無に応じてロールオフ率β及びシンボルレートρを変更することによりデータレートを向上させる。 Next, details of the process executed by the transmission parameter determining device 140 of the transmitting device 100 in steps S11 and S15 in FIG. 11 will be described. FIG. 14 is a flow diagram showing a roll-off rate and symbol rate determination algorithm executed by transmission parameter determining device 140 of transmitting device 100. The algorithm shown in FIG. 14 determines the roll-off rate β and symbol rate ρ for the purpose of improving the data rate. In this algorithm, the data rate is improved by changing the roll-off rate β and the symbol rate ρ depending on the presence or absence of the amount of nonlinear distortion estimated by the receiving device 200.
　まず、送信パラメータ決定装置１４０のロールオフ率決定部１４３は、ＰＡＰＲ情報保持部１４２に保持しているルックアップテーブルを参照し、モード多重数に対応した、又は、モード多重数及び送信ＯＡＭモードに対応したロールオフ率を選択し、初期値とする（ステップＳ５１）。このロールオフ率は、ＰＡＰＲを最小とする値である。シンボルレート決定部１４４は、初期値のロールオフ率に対応したシンボルレートを設定する（ステップＳ５２）。シンボルレートは、ロールオフ率に応じて、占有帯域幅の制限範囲内でデータレートを最大化する値として事前に決定される。ロールオフ率決定部１４３は、繰り返し回数を表す変数ｉに０を設定する（ステップＳ５３）。 First, the roll-off rate determining unit 143 of the transmission parameter determining device 140 refers to the lookup table held in the PAPR information holding unit 142, and selects a value corresponding to the number of mode multiplexing or the number of mode multiplexing and the transmission OAM mode. A corresponding roll-off rate is selected and set as an initial value (step S51). This roll-off rate is a value that minimizes PAPR. The symbol rate determination unit 144 sets a symbol rate corresponding to the initial roll-off rate (step S52). The symbol rate is predetermined according to the roll-off rate as a value that maximizes the data rate within the limited range of occupied bandwidth. The roll-off rate determining unit 143 sets a variable i representing the number of repetitions to 0 (step S53).
　送信装置１００の通信パラメータ取得部１４１は、非線形歪み取得装置１１０が受信装置２００から受信した非線形歪み情報を取得する（ステップＳ５４）。ロールオフ率決定部１４３は、取得した非線形歪み情報が非線形歪み有りを示すか否かを判断する（ステップＳ５５）。 The communication parameter acquisition unit 141 of the transmitting device 100 acquires the nonlinear distortion information that the nonlinear distortion acquisition device 110 receives from the receiving device 200 (step S54). The roll-off rate determining unit 143 determines whether the acquired nonlinear distortion information indicates that nonlinear distortion is present (step S55).
　ロールオフ率決定部１４３は、非線形歪み情報が非線形歪みなしを示すと判断した場合（ステップＳ５５：ＮＯ）、ステップＳ５６の処理を行う。すなわち、ロールオフ率決定部１４３は、ロールオフ率を現在の値βからΔβだけ低下させた値に更新する。さらに、シンボルレート決定部１４４は、シンボルレートを更新後のロールオフ率βに対応したρ（β）に変更する（ステップＳ５６）。ロールオフ率決定部１４３は、変数ｉの値に１を加算する（ステップＳ５７）。送信パラメータ決定装置１４０は、変更後のロールオフ率及びシンボルレートの情報をロールオフフィルタ適用装置１６０に通知し、ステップＳ５４からの処理を繰り返す。 When the roll-off rate determining unit 143 determines that the nonlinear distortion information indicates no nonlinear distortion (step S55: NO), it performs the process of step S56. That is, the roll-off rate determination unit 143 updates the roll-off rate to a value that is lowered by Δβ from the current value β. Further, the symbol rate determining unit 144 changes the symbol rate to ρ(β) corresponding to the updated roll-off rate β (step S56). The roll-off rate determining unit 143 adds 1 to the value of the variable i (step S57). The transmission parameter determining device 140 notifies the roll-off filter applying device 160 of the changed roll-off rate and symbol rate information, and repeats the processing from step S54.
　一方、ロールオフ率決定部１４３は、非線形歪み情報が非線形歪み有りを示すと判断した場合（ステップＳ５５：ＹＥＳ）、変数ｉが０であるか否かを判断する（ステップＳ５８）。変数ｉが０の場合、現在のロールオフ率は、ＰＡＰＲを最小にする初期値のロールオフ率である。そこで、ロールオフ率決定部１４３は、変数ｉが０であると判断した場合（ステップＳ５８：ＹＥＳ）、信号処理装置１３０に送信電力を下げるよう指示する（ステップＳ５９）。信号処理装置１３０は、この指示を受信すると、ロールオフフィルタ適用装置１６０に出力する信号の振幅を小さくする。 On the other hand, when the roll-off rate determining unit 143 determines that the nonlinear distortion information indicates the presence of nonlinear distortion (step S55: YES), it determines whether the variable i is 0 (step S58). If the variable i is 0, the current rolloff rate is the initial rolloff rate that minimizes PAPR. Therefore, when the roll-off rate determining unit 143 determines that the variable i is 0 (step S58: YES), it instructs the signal processing device 130 to lower the transmission power (step S59). Upon receiving this instruction, the signal processing device 130 reduces the amplitude of the signal output to the roll-off filter applying device 160.
　一方、変数ｉが０ではない場合、現在のロールオフ率はＰＡＰＲを最小とするものではない。ロールオフ率決定部１４３は、変数ｉが０ではないと判断した場合（ステップＳ５８：ＮＯ）、ステップＳ６０の処理を行う。すなわち、ロールオフ率決定部１４３は、ロールオフ率を現在の値βからΔβだけ上げた値に更新する。さらに、シンボルレート決定部１４４は、シンボルレートを更新後のロールオフ率βに対応したρ（β）とする（ステップＳ６０）。送信パラメータ決定装置１４０は、変更後のロールオフ率及びシンボルレートの情報をロールオフフィルタ適用装置１６０に通知する。 On the other hand, if the variable i is not 0, the current rolloff rate does not minimize PAPR. When the roll-off rate determining unit 143 determines that the variable i is not 0 (step S58: NO), it performs the process of step S60. That is, the roll-off rate determination unit 143 updates the roll-off rate to a value that is increased by Δβ from the current value β. Furthermore, the symbol rate determining unit 144 sets the symbol rate to ρ(β) corresponding to the updated roll-off rate β (step S60). The transmission parameter determining device 140 notifies the roll-off filter application device 160 of the changed roll-off rate and symbol rate information.
　なお、Δβはロールオフ率の刻み幅である。Δβには、例えば、０．０５等の値を用いる。ρ（β）は、ロールオフ率βの場合に占有帯域幅の制限下でデータレートを最大化するシンボルレートである。ロールオフ率とシンボルレートの関係は、例えば事前に計算して送信装置１００に保持しておくか、送信パラメータ決定装置１４０がその都度計算する。図１４に示すアルゴリズムは、通信開始のタイミングのみで実行してもよいし、適切な間隔で複数回実行してもよい。 Note that Δβ is the step width of the roll-off rate. For example, a value such as 0.05 is used for Δβ. ρ(β) is the symbol rate that maximizes the data rate under the occupied bandwidth limit for the roll-off rate β. The relationship between the roll-off rate and the symbol rate is, for example, calculated in advance and stored in the transmitting device 100, or is calculated each time by the transmission parameter determining device 140. The algorithm shown in FIG. 14 may be executed only at the timing of starting communication, or may be executed multiple times at appropriate intervals.
　送信装置１００及び受信装置２００のハードウェア構成例を説明する。図１５は、送信装置１００及び受信装置２００のハードウェア構成例を示す装置構成図である。送信装置１００及び受信装置２００は、プロセッサ７１と、記憶部７２と、通信インタフェース７３と、ユーザインタフェース７４とを備える。 An example of the hardware configuration of the transmitting device 100 and the receiving device 200 will be described. FIG. 15 is a device configuration diagram showing an example of the hardware configuration of the transmitting device 100 and the receiving device 200. The transmitting device 100 and the receiving device 200 include a processor 71, a storage unit 72, a communication interface 73, and a user interface 74.
　プロセッサ７１は、演算や制御を行う中央演算装置である。プロセッサ７１は、例えば、ＣＰＵである。プロセッサ７１は、記憶部７２からプログラムを読み出して実行する。送信装置１００及び受信装置２００の機能の一部は、ＡＳＩＣ（Application Specific Integrated Circuit）やＰＬＤ（Programmable Logic Device）やＦＰＧＡ（Field Programmable Gate Array）等のハードウェアを用いて実現されてもよい。記憶部７２は、さらに、プロセッサ７１が各種プログラムを実行する際のワークエリアなどを有する。通信インタフェース７３は、他装置と通信可能に接続するものである。ユーザインタフェース７４は、キーボード、ポインティングデバイス（マウス、タブレット等）、ボタン、タッチパネル等の入力装置や、ディスプレイなどの表示装置である。ユーザインタフェース７４により、人為的な操作が入力される。 The processor 71 is a central processing unit that performs calculations and control. Processor 71 is, for example, a CPU. The processor 71 reads a program from the storage unit 72 and executes it. Some of the functions of the transmitting device 100 and the receiving device 200 may be realized using hardware such as an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array). The storage unit 72 further includes a work area when the processor 71 executes various programs. The communication interface 73 is communicably connected to other devices. The user interface 74 is an input device such as a keyboard, a pointing device (mouse, tablet, etc.), a button, a touch panel, or a display device such as a display. A human operation is input through the user interface 74 .
　上述した実施形態によれば、無線通信システムは、送信装置と受信装置とを有する。送信装置は、決定部と、フィルタ適用部と、送信部と、変更部とを備える。決定部は、例えば、実施形態の送信パラメータ決定装置１４０に対応する。決定部は、各ＯＡＭモードを用いた信号を多重したＯＡＭ多重信号の変調方式を表すパラメータの少なくとも一部に基づいてロールオフ率を決定する。フィルタ適用部は、例えば、実施形態のロールオフフィルタ適用装置１６０に対応する。フィルタ適用部は、決定部が決定したロールオフ率を用いて送信信号にロールオフフィルタ処理を適用する。送信部は、例えば、実施形態のＯＡＭモード生成装置１７０、ＲＦチェーン１８０及びＵＣＡ１９０に対応する。送信部は、フィルタ適用部によりロールオフフィルタ処理が行われた送信信号から変調方式に従ってＯＡＭ多重信号を生成し、生成されたＯＡＭ多重信号を送信する。変更部は、例えば、実施形態の送信パラメータ決定装置１４０に対応する。変更部は、受信装置におけるＯＡＭ多重信号の非線形歪みの推定結果に基づいてロールオフ率を変更する。 According to the embodiments described above, the wireless communication system includes a transmitting device and a receiving device. The transmitting device includes a determining section, a filter applying section, a transmitting section, and a changing section. The determining unit corresponds to, for example, the transmission parameter determining device 140 of the embodiment. The determining unit determines the roll-off rate based on at least part of a parameter representing a modulation method of an OAM multiplex signal obtained by multiplexing signals using each OAM mode. The filter application unit corresponds to, for example, the roll-off filter application device 160 of the embodiment. The filter application section applies roll-off filter processing to the transmission signal using the roll-off rate determined by the determination section. The transmitter corresponds to, for example, the OAM mode generator 170, RF chain 180, and UCA 190 of the embodiment. The transmitter generates an OAM multiplex signal according to a modulation scheme from the transmission signal subjected to roll-off filter processing by the filter application unit, and transmits the generated OAM multiplex signal. The changing unit corresponds to, for example, the transmission parameter determining device 140 of the embodiment. The changing unit changes the roll-off rate based on the estimation result of nonlinear distortion of the OAM multiplexed signal in the receiving device.
　決定部は、情報保持部と、ロールオフ率決定部と、シンボルレート決定部とを有してもよい。情報保持部は、例えば、実施形態のＰＡＰＲ情報保持部１４２に対応する。情報保持部は、ロールオフ率とパラメータとの対応を示す情報を保持する。ロールオフ率決定部は、変調方式を表すパラメータの少なくとも一部に基づいて情報保持部からロールオフ率を読み出す。シンボルレート決定部は、ロールオフ率決定部が読み出したロールオフ率に基づいてシンボルレートを決定する。フィルタ適用部は、シンボルレート決定部が決定したシンボルレートを用いた送信信号に、ロールオフ率決定部が読み出したロールオフ率を用いたロールオフフィルタ処理を適用する。 The determining unit may include an information holding unit, a roll-off rate determining unit, and a symbol rate determining unit. The information holding unit corresponds to, for example, the PAPR information holding unit 142 of the embodiment. The information holding unit holds information indicating the correspondence between roll-off rates and parameters. The roll-off rate determining unit reads the roll-off rate from the information holding unit based on at least part of the parameters representing the modulation method. The symbol rate determining section determines the symbol rate based on the roll-off rate read by the roll-off rate determining section. The filter application section applies roll-off filter processing using the roll-off rate read by the roll-off rate determination section to the transmission signal using the symbol rate determined by the symbol rate determination section.
　パラメータは、モード多重数、送信モード、変調多値数、及び、シンボルレートのうち一以上である。 The parameter is one or more of mode multiplexing number, transmission mode, modulation level number, and symbol rate.
　受信装置は、受信部と、推定部と、通知部とを備える。受信部は、例えば、実施形態のＵＣＡ２１０、ＲＦチェーン２２０、ＯＡＭモード分離装置２３０及び受信信号処理装置２４０に対応する。受信部は、送信装置から受信したＯＡＭ多重信号の受信処理を行う。推定部は、例えば、実施形態の非線形歪み推定装置２６０に対応する。推定部は、受信部が受信処理したＯＡＭ多重信号の非線形歪みを推定する。推定部は、受信部が受信処理したＯＡＭ多重信号のコンスタレーションにおける高い電圧の信号点の平均２乗誤差及び低い電圧の信号点の平均２乗誤差の差分に基づいて非線形歪みを推定してもよい。通知部は、例えば、実施形態の非線形歪み通知装置２８０に対応する。通知部は、推定部による推定結果を送信装置に通知する。受信部は、推定結果に基づいて変更されたロールオフ率を用いたロールオフフィルタ処理が適用された送信信号から生成されたＯＡＭ多重信号を送信装置から受信する。 The receiving device includes a receiving section, an estimating section, and a notifying section. The receiving unit corresponds to, for example, the UCA 210, RF chain 220, OAM mode separation device 230, and received signal processing device 240 of the embodiment. The receiving unit performs a receiving process on the OAM multiplex signal received from the transmitting device. The estimator corresponds to, for example, the nonlinear distortion estimator 260 of the embodiment. The estimator estimates nonlinear distortion of the OAM multiplex signal received and processed by the receiver. The estimating unit may estimate the nonlinear distortion based on the difference between the mean square error of high voltage signal points and the mean square error of low voltage signal points in the constellation of the OAM multiplex signal received and processed by the receiving unit. good. The notification unit corresponds to, for example, the nonlinear distortion notification device 280 of the embodiment. The notification unit notifies the transmitting device of the estimation result by the estimation unit. The receiving unit receives from the transmitting device an OAM multiplexed signal generated from a transmitted signal to which roll-off filter processing using a roll-off rate changed based on the estimation result has been applied.
　推定部は、分類部と、算出部と、比較部とを有してもよい。分類部は、例えば、実施形態のコンスタレーション抽出部２６１に対応する。分類部は、受信部が受信処理したＯＡＭ多重信号の信号点の電圧に基づき信号点を分類する。算出部は、例えば、実施形態のＥＶＭ算出部２６２に対応する。算出部は、高い電圧に分類された信号点である第一信号点のエラーベクトル振幅と、低い電圧に分類された信号点である第二信号点のエラーベクトル振幅とを算出する。比較部は、例えば、実施形態のＥＶＭ比較部２６３に対応する。比較部は、第一信号点のエラーベクトル振幅の平均２乗誤差と、第二信号点のエラーベクトル振幅の平均２乗誤差との差分が所定以上である場合に非線形歪みが発生していると判断する。 The estimation unit may include a classification unit, a calculation unit, and a comparison unit. The classification unit corresponds to, for example, the constellation extraction unit 261 of the embodiment. The classification unit classifies the signal points based on the voltages of the signal points of the OAM multiplex signal received and processed by the reception unit. The calculation unit corresponds to, for example, the EVM calculation unit 262 of the embodiment. The calculation unit calculates an error vector amplitude of a first signal point that is a signal point classified as a high voltage, and an error vector amplitude of a second signal point that is a signal point classified as a low voltage. The comparison unit corresponds to, for example, the EVM comparison unit 263 of the embodiment. The comparison unit determines that nonlinear distortion has occurred when the difference between the mean square error of the error vector amplitude of the first signal point and the mean square error of the error vector amplitude of the second signal point is greater than or equal to a predetermined value. to decide.
　以上、この発明の実施形態について図面を参照して詳述してきたが、具体的な構成はこの実施形態に限られるものではなく、この発明の要旨を逸脱しない範囲の設計等も含まれる。 Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and includes designs within the scope of the gist of the present invention.
１　無線通信システム
１１　無線伝送装置
１２　無線伝送装置
７１　プロセッサ
７２　記憶部
７３　通信インタフェース
７４　ユーザインタフェース
１００　送信装置
１１０　取得装置
１２０　送信制御装置
１２１　通信性能取得部
１２２　送信ＯＡＭモード決定部
１２３　多重数決定部
１２４　送信信号パラメータ決定部
１３０　信号処理装置
１４０　送信パラメータ決定装置
１４１　通信パラメータ取得部
１４２　ＰＡＰＲ情報保持部
１４３　ロールオフ率決定部
１４４　シンボルレート決定部
１５０　送信パラメータ通知装置
１６０　ロールオフフィルタ適用装置
１７０　ＯＡＭモード生成装置
１８０　ＲＦチェーン
１９０　ＵＣＡ
１９１－１～１９１－Ｍ　アンテナ素子
２００　受信装置
２１０　ＵＣＡ
２２０　ＲＦチェーン
２３０　ＯＡＭモード分離装置
２４０　受信信号処理装置
２５０　ロールオフ率取得装置
２６０　推定装置
２６１　コンスタレーション抽出部
２６２　ＥＶＭ算出部
２６３　ＥＶＭ比較部
２７０　復調器
２８０　通知装置 1 Wireless communication system 11 Wireless transmission device 12 Wireless transmission device 71 Processor 72 Storage unit 73 Communication interface 74 User interface 100 Transmission device 110 Acquisition device 120 Transmission control device 121 Communication performance acquisition unit 122 Transmission OAM mode determination unit 123 Multiplex number determination unit 124 Transmission signal parameter determination section 130 Signal processing device 140 Transmission parameter determination device 141 Communication parameter acquisition section 142 PAPR information holding section 143 Roll-off rate determination section 144 Symbol rate determination section 150 Transmission parameter notification device 160 Roll-off filter application device 170 OAM mode generation Device 180 RF chain 190 UCA
191-1 to 191-M Antenna element 200 Receiving device 210 UCA
220 RF chain 230 OAM mode separation device 240 Received signal processing device 250 Roll-off rate acquisition device 260 Estimation device 261 Constellation extraction section 262 EVM calculation section 263 EVM comparison section 270 Demodulator 280 Notification device

Claims (7)

  1. 　送信装置が、各ＯＡＭ（Orbital Angular Momentum）モードを用いた信号を多重したＯＡＭ多重信号の変調方式を表すパラメータの少なくとも一部に基づいてロールオフ率を決定する決定ステップと、
    　前記送信装置が、前記決定ステップにおいて決定された前記ロールオフ率を用いて送信信号にロールオフフィルタ処理を適用するフィルタ適用ステップと、
    　前記送信装置が、前記フィルタ適用ステップにおいて前記ロールオフフィルタ処理が行われた前記送信信号から前記変調方式に従ってＯＡＭ多重信号を生成し、生成された前記ＯＡＭ多重信号を送信する送信ステップと、
    　受信装置が、前記送信装置から受信した前記ＯＡＭ多重信号の受信処理を行う受信処理ステップと、
    　前記受信装置が、前記受信処理ステップにおいて受信処理された前記ＯＡＭ多重信号の非線形歪みを推定する推定ステップと、
    　前記受信装置が、前記推定ステップにおける推定結果を前記送信装置に通知する通知ステップと、
    　前記送信装置が、前記受信装置から通知された前記推定結果に基づいて前記ロールオフ率を変更する変更ステップと、
    　を有する無線通信方法。     a determining step in which the transmitting device determines a roll-off rate based on at least part of a parameter representing a modulation method of an OAM multiplexed signal obtained by multiplexing signals using each OAM (Orbital Angular Momentum) mode;
    a filter applying step in which the transmitting device applies roll-off filter processing to the transmission signal using the roll-off rate determined in the determining step;
    a transmitting step in which the transmitting device generates an OAM multiplex signal according to the modulation method from the transmit signal subjected to the roll-off filter processing in the filter applying step, and transmits the generated OAM multiplex signal;
    a reception processing step in which a reception device performs reception processing of the OAM multiplexed signal received from the transmission device;
    an estimation step in which the receiving device estimates nonlinear distortion of the OAM multiplex signal subjected to reception processing in the reception processing step;
    a notification step in which the receiving device notifies the transmitting device of the estimation result in the estimation step;
    a changing step in which the transmitting device changes the roll-off rate based on the estimation result notified from the receiving device;
    A wireless communication method having.
  2. 　送信装置と受信装置とを有する無線通信システムであって、
    　前記送信装置は、
    　各ＯＡＭ（Orbital Angular Momentum）モードを用いた信号を多重したＯＡＭ多重信号の変調方式を表すパラメータの少なくとも一部に基づいてロールオフ率を決定する決定部と、
    　前記決定部が決定した前記ロールオフ率を用いて送信信号にロールオフフィルタ処理を適用するフィルタ適用部と、
    　前記フィルタ適用部により前記ロールオフフィルタ処理が行われた前記送信信号から前記変調方式に従ってＯＡＭ多重信号を生成し、生成された前記ＯＡＭ多重信号を送信する送信部と、
    　前記受信装置における前記ＯＡＭ多重信号の非線形歪みの推定結果に基づいて前記ロールオフ率を変更する変更部とを備え、
    　前記受信装置は、
    　前記送信装置から受信した前記ＯＡＭ多重信号の受信処理を行う受信部と、
    　前記受信部が受信処理した前記ＯＡＭ多重信号の非線形歪みを推定する推定部と、
    　前記推定部による推定結果を前記送信装置に通知する通知部とを備える、
    　無線通信システム。     A wireless communication system having a transmitting device and a receiving device,
    The transmitting device includes:
    a determining unit that determines a roll-off rate based on at least a part of a parameter representing a modulation method of an OAM multiplexed signal obtained by multiplexing signals using each OAM (Orbital Angular Momentum) mode;
    a filter application unit that applies roll-off filter processing to the transmission signal using the roll-off rate determined by the determination unit;
    a transmitting unit that generates an OAM multiplexed signal according to the modulation method from the transmission signal subjected to the roll-off filter processing by the filter application unit, and transmits the generated OAM multiplexed signal;
    a changing unit that changes the roll-off rate based on an estimation result of nonlinear distortion of the OAM multiplexed signal in the receiving device,
    The receiving device includes:
    a receiving unit that performs reception processing of the OAM multiplexed signal received from the transmitting device;
    an estimator that estimates nonlinear distortion of the OAM multiplex signal received and processed by the receiver;
    and a notification unit that notifies the transmitting device of the estimation result by the estimation unit,
    Wireless communication system.
  3. 　各ＯＡＭ（Orbital Angular Momentum）モードを用いた信号を多重したＯＡＭ多重信号の変調方式を表すパラメータの少なくとも一部に基づいてロールオフ率とシンボルレートを決定する決定部と、
    　前記決定部が決定した前記ロールオフ率を用いて送信信号にロールオフフィルタ処理を適用するフィルタ適用部と、
    　前記フィルタ適用部により前記ロールオフフィルタ処理が行われた前記送信信号から前記変調方式に従ってＯＡＭ多重信号を生成し、生成された前記ＯＡＭ多重信号を送信する送信部と、
    　受信装置における前記ＯＡＭ多重信号の非線形歪みの推定結果に基づいて前記ロールオフ率を変更する変更部と、
    　を備える送信装置。     a determining unit that determines a roll-off rate and a symbol rate based on at least a part of parameters representing a modulation method of an OAM multiplexed signal obtained by multiplexing signals using each OAM (Orbital Angular Momentum) mode;
    a filter application unit that applies roll-off filter processing to the transmission signal using the roll-off rate determined by the determination unit;
    a transmitting unit that generates an OAM multiplex signal according to the modulation method from the transmission signal subjected to the roll-off filter processing by the filter application unit, and transmits the generated OAM multiplex signal;
    a changing unit that changes the roll-off rate based on an estimation result of nonlinear distortion of the OAM multiplexed signal in a receiving device;
    A transmitting device comprising:
  4. 　前記決定部は、
    　ロールオフ率とパラメータとの対応を示す情報を保持する情報保持部と、
    　前記変調方式を表すパラメータの少なくとも一部に基づいて前記情報保持部から前記ロールオフ率を読み出すロールオフ率決定部と、
    　前記ロールオフ率決定部が読み出した前記ロールオフ率に基づいてシンボルレートを決定するシンボルレート決定部とを備え、
    　前記フィルタ適用部は、前記シンボルレート決定部が決定した前記シンボルレートを用いた前記送信信号に、前記ロールオフ率決定部が読み出した前記ロールオフ率を用いた前記ロールオフフィルタ処理を適用する、
    　請求項３に記載の送信装置。     The determining unit is
    an information holding unit that holds information indicating the correspondence between the roll-off rate and the parameter;
    a roll-off rate determining unit that reads the roll-off rate from the information holding unit based on at least a part of the parameters representing the modulation method;
    a symbol rate determining unit that determines a symbol rate based on the roll-off rate read by the roll-off rate determining unit;
    The filter applying unit applies the roll-off filter processing using the roll-off rate read by the roll-off rate determining unit to the transmission signal using the symbol rate determined by the symbol rate determining unit.
    The transmitting device according to claim 3.
  5. 　前記パラメータは、モード多重数、送信モード、変調多値数、及び、シンボルレートのうち一以上である、
    　請求項３に記載の送信装置。     The parameter is one or more of mode multiplexing number, transmission mode, modulation level number, and symbol rate.
    The transmitting device according to claim 3.
  6. 　各ＯＡＭ（Orbital Angular Momentum）モードを用いた信号を多重したＯＡＭ多重信号を送信装置から受信し、受信した前記ＯＡＭ多重信号の受信処理を行う受信部と、
    　前記受信部が受信処理した前記ＯＡＭ多重信号のコンスタレーションにおける高い電圧の信号点の平均２乗誤差及び低い電圧の信号点の平均２乗誤差の差分に基づいて非線形歪みを推定する推定部と、
    　前記推定部による推定結果を前記送信装置に通知する通知部と、
    　を備え、
    　前記受信部は、前記推定結果に基づいて変更されたロールオフ率を用いたロールオフフィルタ処理が適用された送信信号から生成されたＯＡＭ多重信号を前記送信装置から受信する、
    　受信装置。     a receiving unit that receives an OAM multiplexed signal obtained by multiplexing signals using each OAM (Orbital Angular Momentum) mode from a transmitter, and performs reception processing of the received OAM multiplexed signal;
    an estimating unit that estimates nonlinear distortion based on a difference between a mean square error of a high voltage signal point and a mean square error of a low voltage signal point in the constellation of the OAM multiplex signal received and processed by the receiving unit;
    a notification unit that notifies the transmitting device of the estimation result by the estimation unit;
    Equipped with
    The receiving unit receives from the transmitting device an OAM multiplexed signal generated from a transmitted signal to which roll-off filter processing using a roll-off rate changed based on the estimation result has been applied.
    Receiving device.
  7. 　前記推定部は、
    　前記受信部が受信処理した前記ＯＡＭ多重信号の信号点の電圧に基づき信号点を分類する分類部と、
    　高い電圧に分類された前記信号点である第一信号点のエラーベクトル振幅と、低い電圧に分類された前記信号点である第二信号点のエラーベクトル振幅とを算出する算出部と、
    　前記第一信号点の前記エラーベクトル振幅の平均２乗誤差と、前記第二信号点の前記エラーベクトル振幅の平均２乗誤差との差分が所定以上である場合に非線形歪みが発生していると判断する比較部とを備える、
    　請求項６に記載の受信装置。     The estimation unit is
    a classification unit that classifies signal points based on the voltage of the signal points of the OAM multiplex signal received and processed by the reception unit;
    a calculation unit that calculates an error vector amplitude of a first signal point, which is the signal point classified as a high voltage, and an error vector amplitude of a second signal point, which is the signal point classified as a low voltage;
    If the difference between the mean square error of the error vector amplitude of the first signal point and the mean square error of the error vector amplitude of the second signal point is greater than or equal to a predetermined value, it is determined that nonlinear distortion has occurred. and a comparison section for making a determination.
    The receiving device according to claim 6.
PCT/JP2022/017776 2022-04-14 2022-04-14 Wireless communication method, wireless communication system, transmission device, and reception device WO2023199462A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/JP2022/017776 WO2023199462A1 (en) 2022-04-14 2022-04-14 Wireless communication method, wireless communication system, transmission device, and reception device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2022/017776 WO2023199462A1 (en) 2022-04-14 2022-04-14 Wireless communication method, wireless communication system, transmission device, and reception device

Publications (1)

Publication Number Publication Date
WO2023199462A1 true WO2023199462A1 (en) 2023-10-19

Family

ID=88329369

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2022/017776 WO2023199462A1 (en) 2022-04-14 2022-04-14 Wireless communication method, wireless communication system, transmission device, and reception device

Country Status (1)

Country Link
WO (1) WO2023199462A1 (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003015443A1 (en) * 2001-08-01 2003-02-20 Mitsubishi Denki Kabushiki Kaisha Mobile communication system, mobile communication method, base station, and mobile station
JP2013236302A (en) * 2012-05-10 2013-11-21 Sharp Corp Mobile station device, base station device, transmission method, and wireless communication system
WO2019116774A1 (en) * 2017-12-14 2019-06-20 日本電気株式会社 Radio transmission device, baseband processing device, radio transmission method, and radio reception device

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003015443A1 (en) * 2001-08-01 2003-02-20 Mitsubishi Denki Kabushiki Kaisha Mobile communication system, mobile communication method, base station, and mobile station
JP2013236302A (en) * 2012-05-10 2013-11-21 Sharp Corp Mobile station device, base station device, transmission method, and wireless communication system
WO2019116774A1 (en) * 2017-12-14 2019-06-20 日本電気株式会社 Radio transmission device, baseband processing device, radio transmission method, and radio reception device

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
MUTA, OSAMU: "Adaptive Peak-Amplitude Suppression Techniques for Multi-carrier Signals", IEICE TECHNICAL REPORT, SAT, IEICE, JP, vol. 115, no. 180 (SAT2015-20), 10 August 2015 (2015-08-10), JP, pages 53 - 58, XP009549618 *

Similar Documents

Publication Publication Date Title
CN101953099B (en) Channel estimation method and system for inter-carrier interference-limited wireless communication network
US7212793B2 (en) Radio reception apparatus and radio reception method
EP3591922B1 (en) Phase adjustment method, related device and communication system
US6177906B1 (en) Multimode iterative adaptive smart antenna processing method and apparatus
KR101564479B1 (en) Method and system for reduced complexity channel estimation and interference cancellation for v-mimo demodulation
US9614712B2 (en) Method for reducing PAPR in a transmission of a multi-carrier signal, and corresponding transmission device and computer program
JP4829705B2 (en) Peak suppression control device
JP4409743B2 (en) Wireless communication apparatus and wireless communication system
US7792495B2 (en) Radio apparatus, transmission control method and transmission control program
WO2007029406A1 (en) Adaptive radio/modulation apparatus, receiver apparatus, wireless communication system and wireless communication method
NO326386B1 (en) Precise predetermination of signal-to-signal ratio in a communication system
JP4871813B2 (en) Wireless communication device, wireless communication method, and peak suppression method
WO2012102935A1 (en) Peak-to-average power ratio reduction for hybrid fm hd radio transmission
WO2009092150A1 (en) Peak-to-average power reduction method
US20150085748A1 (en) System and method for controlling peak to average power ratio
EP1418721B1 (en) System and method for soft slicing outputs from a beamformer
EP1985026A2 (en) Wireless communication unit and method for receiving a wireless signal
JP5361827B2 (en) Transmitter and transmission method
WO2023199462A1 (en) Wireless communication method, wireless communication system, transmission device, and reception device
WO2003047195A1 (en) Power amplifier transient compensation in ofdm systems
Dinis et al. A multi-antenna technique for mm-wave communications with large constellations and strongly nonlinear amplifiers
WO2023199467A1 (en) Radio communication method, radio communication system, transmission device, and reception device
EP1838030A2 (en) Uplink signal receiving method and apparatus using successive interference cancellation in wireless transmission system based on OFDMA
Lee et al. Downlink OFDMA with DFT-precoding for tera-hertz communications
WO2023199461A1 (en) Wireless communication method, wireless communication system, transmission device, and reception device

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22937441

Country of ref document: EP

Kind code of ref document: A1