CN118275999A

CN118275999A - Method, device, integrated circuit, radio device and terminal for calibrating emission phase

Info

Publication number: CN118275999A
Application number: CN202211730947.9A
Authority: CN
Inventors: 张磊; 陈熠; 王晓
Original assignee: Calterah Semiconductor Technology Shanghai Co Ltd
Current assignee: Calterah Semiconductor Technology Shanghai Co Ltd
Priority date: 2022-12-30
Filing date: 2022-12-30
Publication date: 2024-07-02

Abstract

A transmission phase calibration method, apparatus, integrated circuit, radio device and terminal device, the transmission phase calibration for each transmission channel of MIMO radar includes: transmitting test signals to each phase to be tested in a plurality of phases to be tested, taking the phase to be tested as the transmitting phase of the transmitting channel, and detecting the phase of an echo signal generated after the test signals are reflected by a set target to obtain an actual measurement phase corresponding to the phase to be tested; and for each target phase of the transmitting channel during operation, determining the phase to be detected of which the corresponding measured phase is closest to the target phase from the multiple phases to be detected, and determining the determined phase to be detected as the transmitting phase used when the transmitting channel is to transmit the signal with the target phase. The embodiment of the application improves the accuracy of the MIMO radar transmitting phase and can reduce the influence of leakage and coupling among transmitting channels.

Description

Method, device, integrated circuit, radio device and terminal for calibrating emission phase

Technical Field

The present application relates to, but is not limited to, radar signal processing technology, and more particularly to a transmit phase calibration method, apparatus, integrated circuit, radio device and terminal equipment.

Background

In recent years, as the application of radars in the fields of automatic driving, security protection, unmanned aerial vehicles and the like is more and more widespread, higher demands are put forward on the accuracy of target angle detection of the radars in the application process. At present, a target phase is adopted as a phase modulated when a MIMO (Multiple-Input Multiple-Output) radar is transmitted, but the target phase and a signal phase in actual transmission have larger deviation sometimes, the precision is low, and the coupling between transmission channels is stronger.

Disclosure of Invention

The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

The embodiment of the application provides a transmitting phase calibration method, which comprises the following steps: performing transmit phase calibration for a plurality of transmit channels of the MIMO radar, the transmit phase calibration for each of the transmit channels comprising:

Transmitting a test signal to each phase to be tested in a plurality of phases to be tested, taking the phase to be tested as the transmitting phase of the transmitting channel, and detecting the phase of an echo signal generated after the test signal is reflected by a set target to obtain an actual measurement phase corresponding to the phase to be tested;

and for each target phase of the transmitting channel during operation, determining the phase to be detected of which the corresponding measured phase is closest to the target phase from the multiple phases to be detected, and determining the determined phase to be detected as the transmitting phase used when the transmitting channel is to transmit the signal with the target phase.

In some alternative embodiments, the MIMO radar supports transmission of DDM-MIMO waveform signals over the plurality of transmit channels.

In some optional embodiments, the phases to be measured of the multiple transmitting channels are uniformly configured according to a preset phase table of the MIMO radar, and the multiple phases to be measured configured for each transmitting channel are the same; or alternatively

The phases to be detected of the plurality of transmitting channels are respectively configured according to a preset phase table of the MIMO radar and respective target phases of the plurality of transmitting channels, and the plurality of phases to be detected configured for each transmitting channel are at least partially different.

In some alternative embodiments, the plurality of phases to be measured configured for each transmit channel are the same;

When the transmitting phases of the multiple transmitting channels of the MIMO radar are calibrated, at least one frame of signals is transmitted based on each phase to be detected in the multiple phases to be detected, each frame of signals comprises M multiplied by N test signals transmitted by the multiple transmitting channels in a time sharing mode, the transmitting phases of the M multiplied by N test signals are all phases to be detected, M is the number of the multiple transmitting channels, M is more than or equal to 2, N is the number of the test signals transmitted by each transmitting channel in each frame of signals, and N is more than or equal to 1.

In some optional embodiments, the detecting the phase of the echo signal generated after the test signal is reflected by the set target to obtain the measured phase corresponding to the phase to be measured includes: and respectively carrying out target search based on the received signals of a plurality of receiving channels of the MIMO radar, acquiring phases of the echo signals received by the receiving channels, and taking the acquired phases as measured phases corresponding to the phases to be measured.

In some alternative embodiments, the target search is performed within a determined search range, the search range being determined based on range information in a transmit phase calibration command received by the MIMO radar, or based on configuration information of the MIMO radar.

In some alternative embodiments, determining a phase to be measured of the plurality of phases to be measured that corresponds to a phase to be measured closest to the target phase includes:

Preprocessing a plurality of actual measured phases corresponding to the phases to be detected for each phase to be detected in the plurality of phases to be detected, and calculating a phase difference between the actual measured phase corresponding to the phases to be detected and the target phase based on the preprocessed actual measured phases corresponding to the phases to be detected; wherein the pre-treatment comprises an dephasing winding treatment;

and determining a phase to be measured with the minimum phase difference, wherein the determined phase to be measured is the phase to be measured, of which the corresponding measured phase is closest to the target phase, in the plurality of phases to be measured. '

In some optional embodiments, the preprocessing the plurality of measured phases corresponding to the phase to be measured further includes: and carrying out 0-deviation processing on each measured phase corresponding to the phase to be measured according to the following formula:

Ps_i'＝(Ps_i-Ps_0-i)+Pd₀，i＝1,2,…,I

wherein Ps _i is a measured phase obtained based on the ith receiving channel from among the plurality of measured phases corresponding to the phase to be measured; ps _i' is an actual measured phase corresponding to the phase to be measured after 0 bias treatment; pd ₀ is a reference phase selected from the plurality of phases to be measured; ps _0-i is a measured phase obtained based on the ith receive channel from among a plurality of measured phases corresponding to Pd ₀; i is the number of receiving channels;

the dephasing winding process includes: and performing unwrapping processing on each measured phase corresponding to the phase to be measured after the 0-phase deviation processing.

In some alternative embodiments, the reference phase is 45 °, 135 °, 225 °, or 315 °.

In some alternative embodiments, the method further comprises: after transmitting a test signal for each phase to be tested in a plurality of phases to be tested, taking the phase to be tested as the transmitting phase of the transmitting channel, acquiring the amplitude of the echo signal received by each of the plurality of receiving channels in addition to the phase of the echo signal received by each of the plurality of receiving channels;

The preprocessing of the measured phases corresponding to the phase to be measured further includes: the screening process of the measured phases is performed as follows: searching echo signals with the amplitude smaller than a set amplitude threshold value in the echo signals received by the receiving channels, and deleting the searched phases of the echo signals from the measured phases corresponding to the phases to be detected.

In some optional embodiments, the calculating, based on the preprocessed measured phase corresponding to the phase to be measured, a phase difference between the measured phase corresponding to the phase to be measured and the target phase includes:

Averaging all measured phases corresponding to the preprocessed phase to be detected; and calculating a difference between the average value and the target phase, and taking an absolute value of the difference as the phase difference; or alternatively

Subtracting the target phase from all measured phases corresponding to the preprocessed phase to be detected respectively, determining the difference with the largest absolute value in the obtained differences, and taking the absolute value of the determined difference as the phase difference.

In some alternative embodiments, the MIMO radar is a millimeter wave radar and the test signal is a chirp signal;

The set target is a reflector placed in advance in front of the MIMO radar at a set distance, the reflector and the MIMO radar being placed in the same microwave dark room.

The embodiment of the application also provides a transmitting phase calibration device which is applied to a radar system and can comprise a memory and a processor, wherein the memory stores a computer program, and the transmitting phase calibration method of any embodiment of the application can be realized when the processor executes the computer program.

Embodiments of the present application also provide a non-transitory computer readable storage medium storing a computer program, where the computer program, when executed by a processor, can implement the transmit phase calibration method according to any of the embodiments of the present application.

The embodiment of the application also provides an integrated circuit which can comprise a radio frequency module, an analog signal processing module and a digital signal processing module which are connected in sequence; the radio frequency module is used for generating radio frequency transmitting signals and receiving radio frequency echo signals; the analog signal processing module is used for performing down-conversion processing on the radio frequency echo signal to obtain an intermediate frequency signal; the digital signal processing module is used for carrying out analog-to-digital conversion on the intermediate frequency signal to obtain a digital signal; the digital signal processing module is further configured to perform transmit phase calibration based on the transmit phase calibration method according to any embodiment of the present application.

In some alternative embodiments, the integrated circuit may be a millimeter wave chip.

The embodiment of the application also provides a radio device, which can comprise: a carrier; an integrated circuit as in any one of the embodiments of the application, disposed on a carrier; the antenna is arranged on the supporting body, or the antenna and the integrated circuit are integrated into a whole device and arranged on the supporting body; the integrated circuit is connected with the antenna and is used for transmitting the radio frequency transmitting signal and/or receiving the radio frequency echo signal.

The embodiment of the application also provides a terminal device, which can comprise: an equipment body; and the radio device described in any one of the embodiments provided on the apparatus body; wherein the radio is for object detection and/or communication to provide reference information to the operation of the device body.

According to the transmitting phase calibration method, the transmitting phase calibration device, the integrated circuit, the radio device and the terminal equipment, the corresponding actual measured phases are obtained through actual detection of the plurality of phases to be measured, then for the target phase which is required to be modulated during working, one phase to be measured, which is closest to the target phase, of the corresponding actual measured phases is determined from the plurality of phases to be measured, and the transmitting phase which is used when the transmitting channel is required to transmit signals with the target phase is determined. The MIMO radar can transmit signals by using the stored phases, and the actual phase of the transmitted signals is closest to the target phase, so that the accuracy of the MIMO radar transmitting phase is improved, and leakage and coupling influence among transmitting channels can be reduced.

Additional features and advantages of the application will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the application. Other advantages of the application may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Drawings

The accompanying drawings are included to provide an understanding of the principles of the application, and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain, without limitation, the principles of the application. The shapes and sizes of the various components in the drawings are not to scale, and are intended to illustrate the present application only.

FIG. 1 is a hardware block diagram of a radar system that may be used with embodiments of the present application;

Fig. 2 is a schematic diagram of the transmit antenna array and the receive antenna array of fig. 1;

FIG. 3 is a functional block diagram of a radar system that may be used in the present embodiment;

FIG. 4 is a schematic diagram of a chirp signal of a sawtooth waveform;

FIG. 5 is a flow chart of a transmit phase calibration method according to an embodiment of the present application;

FIG. 6 is a schematic diagram of a single-frame single-phase waveform transmitted by a MIMO radar for transmit phase calibration according to one embodiment of the present application;

Fig. 7 is a schematic diagram of a millimeter wave radar performing transmit phase calibration in accordance with an embodiment of the present application;

fig. 8 is an overall flowchart of a millimeter wave radar performing transmit phase calibration in accordance with an embodiment of the present application;

FIG. 9 is a schematic diagram of a transmit phase calibration apparatus according to an embodiment of the present application;

FIG. 10 is a block diagram of an integrated circuit according to an embodiment of the application;

fig. 11 is a schematic diagram of a radio device according to an embodiment of the application.

Detailed Description

The present application has been described in terms of several embodiments, but the description is illustrative and not restrictive, and it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible within the scope of the described embodiments.

In the description of the present application, words such as "exemplary" or "such as" are used to mean serving as an example, instance, or illustration. Any embodiment described as "exemplary" or "for example" in this disclosure should not be construed as preferred or advantageous over other embodiments. "and/or" herein is a description of an association relationship of an associated object, meaning that there may be three relationships, e.g., a and/or B, which may represent: a exists alone, A and B exist together, and B exists alone. "plurality" means two or more than two. In addition, in order to facilitate the clear description of the technical solution of the embodiments of the present application, the words "first", "second", etc. are used to distinguish the same item or similar items having substantially the same function and function. It will be appreciated by those of skill in the art that the words "first," "second," and the like do not limit the amount and order of execution, and that the words "first," "second," and the like do not necessarily differ.

In the description of the application, "comprising any one or more of the following: option one, option two, … … "or" including any one or more of option one, option two, … … "refers to including any one of the listed options or including any combination of the listed options. For example: "including any one or more of: A. b "or" including any one or more of A, B "means including only A, or only B, or both A and B; another example is: "including any one or more of: A. b, C "or" including any one or more of A, B, C "means that a alone, B alone, C alone, a and B together, a and C together, B and C together, or A, B and C together. More options and so on.

In describing representative exemplary embodiments, the specification may have presented the method and/or process as a particular sequence of steps. However, to the extent that the method or process does not rely on the particular order of steps set forth herein, the method or process should not be limited to the particular sequence of steps described. As will be appreciated by those of ordinary skill in the art, other sequences of steps are possible. Accordingly, the particular order of the steps set forth in the specification should not be construed as limitations on the claims. Furthermore, the claims directed to the method and/or process should not be limited to the performance of their sequences in the order written, and one skilled in the art can readily appreciate that the sequences may be varied and still remain within the spirit and scope of the embodiments of the present application.

The transmitting phase calibration method of the embodiment of the application is used for a radar system, the radar system tracks the position and the speed of a target object (target for short) by detecting the target object, and deduces the movement condition of the target in a three-dimensional space by measuring the position, the radial speed and the angle of the target. In the fields of unmanned automobiles, advanced driving auxiliary systems and the like, the vehicle-mounted millimeter wave radar has the advantages of small volume, low cost, all-weather adaptability and the like, the FMCW (Frequency Modulated Continuous Wave frequency modulation continuous wave) signal is relatively simple to generate and process, higher distance and speed resolution can be obtained, and the vehicle-mounted millimeter wave radar is widely applied to vehicle-mounted millimeter wave radar products.

The following describes the specific technical scheme of the application in detail by taking the transmission phase calibration of the FMCW millimeter wave radar as an example, but the embodiment of the application can also be used for other radar systems.

FIG. 1 illustrates a hardware block diagram of a radar system that may be used with embodiments of the present application. As shown, the radar system includes a radio frequency chip 80, a transmit antenna array 82, a receive antenna array 83, and a main processing chip 81, wherein:

The radio frequency chip 80 is arranged to generate a probe signal and transmit it through the transmit antenna array 82. The detection signal may be an FMCW electromagnetic wave signal.

The transmitting antenna array 82 is connected to the radio frequency chip 80 and has at least two transmitting antennas 821 arranged to transmit probe signals. There may be an initial phase difference between the probe signals transmitted through the different transmit antennas 821.

As an example, the radio frequency chip 80 includes a millimeter wave generator, a power amplifier, and the like to modulate and power amplify the millimeter wave to generate a radio frequency signal. The radio frequency chip 80 has at least two output terminals to provide probe signals to different transmit antennas in the transmit antenna array 82, respectively, during different time periods. In other examples, the radio frequency chip 80 provides probe signals of different phases to multiple transmit antennas in the transmit antenna array 82 simultaneously. For example, a phase shifter may be configured to shift the rf output signal provided by the power amplifier, where the output of the power amplifier and the output of the phase shifter may be used as two output terminals of the rf chip 80.

The receiving antenna array 83 has a plurality of receiving antennas 831 arranged to receive echo signals formed by reflection of the detection signals via objects (i.e., detected objects, target objects, simply referred to as targets). Since the transmission signals radiated by the plurality of transmission antennas can be reflected by the target object to form a plurality of echo signals, the echo signals received by each receiving antenna include a plurality of sets of echo signals corresponding to the plurality of transmission antennas.

As an example, as shown in fig. 2, a space between two transmitting antennas (Tx 1, tx2 in the figure) 821 in the transmitting antenna array 82 is λ/2, where λ is an operating wavelength of the probe signal, and for example, the operating wavelength may be a center operating wavelength of the antenna. The 4 receiving antennas (Rx 1, rx2, rx3, rx4 in the figure) 831 are equally spaced, and the spacing between two adjacent receiving antennas 831 is n·λ/2, and optionally, N is a natural number. In other examples, the number of the transmitting antennas 821 is three or more, the plurality of transmitting antennas 821 are equally spaced apart, and the spacing between two adjacent transmitting antennas 821 is λ/2.

The main processing chip 81 is connected to the receiving antenna array 83 and the radio frequency chip 80, and is configured to process echo signals obtained by the receiving antenna array 83 to obtain information such as a distance, a speed, an angle, and the like of a target. The processing of the echo signal may include mixing, sampling, two-dimensional FFT ((fast Fourier transform, fast Fourier transform), target detection, etc., mixing the echo signal with its local oscillator signal to obtain an intermediate frequency signal, sampling the intermediate frequency signal, performing FFT in distance and speed dimensions to obtain a two-dimensional spectrum of distance and speed, and then determining a peak of the target in the distance and speed dimensions by Constant false alarm detection (Constant FALSE ALARM RATE, CFAR), wherein a frequency corresponding to the peak in the distance dimension includes a difference frequency component and a Doppler frequency component, and is related to the distance and speed of the target, and may be used to calculate a distance between the target and a radar system, and a Doppler frequency corresponding to the peak in the speed dimension is related to a radial speed of the target relative to the radar system, and may be used to calculate a fuzzy speed of the target and perform source number estimation.

In another embodiment, the transmitting antenna 821 and the receiving antenna 831 shown in fig. 1 are connected to the rf chip 80 at the same time to form an rf Transceiver chip (Transceiver), and the main processing chip 81 is only used for processing signals, so as to form a radar signal Transceiver processing system. In yet another embodiment, the functional units in the rf Chip 80 and the main processing Chip 81 shown in fig. 1 are integrated into a SoC (System-on-a-Chip), that is, operations such as receiving and processing of an rf signal can be implemented by one Chip; the transmitting Antenna and the receiving Antenna can be independent of the SoC Chip, or can be integrated with the SoC Chip into a whole to form AiP chips or AoC (Antenna-On-Chip) structures, etc. The transmitting phase calibration method and the corresponding device can be applied to the various chips and the radar system formed by a single chip or a plurality of chips.

Fig. 3 is a functional block diagram of a radar system that may be used in an embodiment of the application. As shown, the radar system includes a transmit antenna 11, a power amplifier 21, a signal generator 23, a receive antenna 13, a low noise amplifier 31, a mixer 33, an analog-to-digital converter (i.e., ADC module) 41, a two-dimensional FFT module 51, and a target detection module 53.

The signal generator 23 may be a millimeter wave generator implemented by an oscillator, and the detection signal generated by the signal generator 23 is amplified by the power amplifier 21 and then transmitted by one or more transmitting antennas 11. In one example, the probe signal is an FMCW signal and the waveform is a sawtooth waveform, as shown in FIG. 4. Each frame of the probing signal includes a plurality of Chirp signals (i.e., chirp), each of which includes an up-band, a down-band, and a frequency-holding band, and the period duration of the Chirp signal is Tc. The signal transmission channel of the radar system is composed of devices such as a signal generator 23 and a power amplifier 21.

The detection signal is reflected and/or refracted by the target to form an echo signal, and the echo signal received by the receiving antenna 13 is amplified by the low noise amplifier 31 and mixed with a corresponding local oscillation signal in the mixer 33 to obtain an intermediate frequency signal. There are typically a plurality of receiving antennas 13. The signal receiving channel of the radar system is formed by low noise amplifier 31, mixer 33 and other device components. The signal transmission channel and the signal reception channel are collectively referred to as a signal transmission/reception channel.

The intermediate frequency signal is sent to an analog-to-digital conversion (ADC) module 41 for sampling to obtain a digital signal, and the digital signal is subjected to distance dimension FFT and speed dimension FFT in a two-dimensional FFT module. The distance dimension FFT is used for performing FFT on sampling points obtained by sampling in each Chirp, and the speed dimension FFT is used for performing FFT on sampling points obtained by sampling in different Chirp. And obtaining a two-dimensional spectrum of the distance and the speed of the digital signal after the two-dimensional FFT, and taking the two-dimensional spectrum as the input of the target detection module.

The object detection module 53 is arranged to detect the distance, speed, angle etc. of the object based on the two-dimensional spectrum. The object detection module 53 includes a CFAR detection unit 531, a ranging unit 533, a speed measurement unit 535, and a goniometer unit 537. The CFAR detection unit 531 determines a spectral peak of the target in the distance and velocity dimensions based on the two-dimensional spectrum. In the case of multiple targets and being distinguishable, targets at different distances have different corresponding spectral peak positions in the distance dimension, and targets at different speeds have different corresponding spectral peak positions in the speed dimension. The distance measuring unit 533 calculates the distance of the target based on the frequency corresponding to the peak in the distance dimension, and may correct the distance based on the doppler frequency in the velocity dimension. The velocimetry unit 535 calculates the velocity of the target from the doppler frequency corresponding to the spectral peak in the velocity dimension in the two-dimensional spectrum. The angle measurement unit 537 may perform target angle detection, such as DOA estimation, according to a method such as maximum likelihood estimation, to obtain the angle of the target.

In one example, the above-described power amplifier 21, signal generator 23, low noise amplifier 31, mixer 33, and the like may be provided in a radio frequency chip as shown in fig. 1. The analog-to-digital conversion module 41, the two-dimensional FFT module 51, and the target detection module 53 described above may be provided in the main processing chip shown in fig. 1, but the present application is not limited thereto. In another example, the modules are integrated in the same chip, and the antenna may be integrated in the chip or may be independent of the chip.

The functional modules included in an actual radar system may be more than the functional modules in fig. 3, or less than the functional modules in fig. 3, or some of the functional modules in fig. 3 may be replaced with other modules. For example, a module for unwrapping the unwrapping phase may be added before the two-dimensional FFT, and units such as clustering, object tracking, object recognition, etc. may be added in the object detection module.

In the application field of millimeter wave radar automobiles, the angle resolution, angle precision and angle robustness index of the radar are directly related to the number and aperture of the receiving channels of the radar, and because of the limitation of the radar size and the number of the receiving channels of the millimeter wave radar chip, MIMO (Multiple-Input Multiple-Output) waveforms are generally adopted to expand the number and aperture of the receiving channels, and common MIMO waveforms comprise TDM (Time Division Multiplexing ) -MIMO waveforms and DDM (doppler division Multiple, doppler division multiplexing) -MIMO waveforms, and the TDM-MIMO waveforms are subjected to channel separation in the time domain to form a plurality of virtual channels; the DDM-MIMO waveform is subjected to channel separation in the Doppler frequency domain to form a plurality of virtual channels. When the DDM-MIMO waveform is used, TX is transmitted simultaneously, the power is higher, the target detection range is far, and the speed non-blurring range is larger. However, the accuracy requirement on the TX transmission phase is higher, if the phase accuracy of modulation during transmission is low, leakage is easy to cause, coupling among transmission channels is strong, and TX sequence calculation errors are easy to cause, so that angle resolution errors are caused.

To this end, an embodiment of the present application provides a transmit phase calibration method for performing transmit phase calibration on a plurality of transmit channels of a MIMO radar, where the transmit phase calibration on each transmit channel is as shown in fig. 5, and includes:

step 110, transmitting a test signal for each phase to be tested in a plurality of phases to be tested, wherein the phase to be tested is taken as a transmitting phase of the transmitting channel, and detecting a phase of an echo signal generated after the test signal is reflected by a set target to obtain an actual measured phase corresponding to the phase to be tested;

And 120, for each target phase when the transmission channel works, determining a phase to be detected, of which the corresponding measured phase is closest to the target phase, from the multiple phases to be detected, and determining the determined phase to be detected as a transmission phase used when the transmission channel is to transmit a signal with the target phase.

The transmitting phase calibration method of the embodiment of the application can be applied to MIMO radars, and realizes the transmitting phase calibration function by installing corresponding software programs. After the user sends a transmitting phase calibration instruction to the MIMO radar, the MIMO radar can execute corresponding calibration operation.

According to the embodiment of the application, the corresponding actual measured phases are obtained by actually detecting the plurality of phases to be detected, and then, for the target phase to be modulated during working, the phase to be detected, of which the corresponding actual measured phase is closest to the target phase, is determined from the plurality of phases to be detected, and the phase to be detected is determined as the transmitting phase used when the transmitting channel is to transmit the signal with the target phase. The MIMO radar can transmit signals by using the determined phases, and the actual phase of the transmitted signals is closest to the target phase, so that the accuracy of the transmission phase of the MIMO radar is improved, and the coupling influence among transmission channels can be reduced.

In an exemplary embodiment of the application, the MIMO radar supports the transmission of DDM-MIMO waveform signals over the plurality of transmit channels.

The target phases of the design of each transmission channel of the MIMO radar are different, for example, the phase difference is 90 degrees, 180 degrees and the like, and if the actual transmitted signal phase is equal to the target phase, leakage can be effectively prevented, and the influence of coupling between channels is avoided. However, it has been found that in practical MIMO radar products, the phase of the transmitted signal deviates from 90 ° after the transmission channel modulates the transmission phase according to the target phase, for example, 90 °, and the deviation is sometimes larger. The phase deviation of each transmitting channel is not the same, and the control is difficult. This can result in greater leakage, stronger coupling between the transmit channels, and even errors in the sequential computation of the transmit channels, which can lead to misconnection.

The embodiment can calibrate the transmitting phase of the transmitting channel before the DDM-MIMO waveform is transmitted, and the calibrated transmitting phase is adopted when the DDM-MIMO waveform is transmitted, so that the actual phase of the transmitting signal is closest to the target phase, thereby reducing the leakage amplitude and reducing the coupling influence between channels. The angle measurement precision is improved, and the angle solution error rate is reduced.

In an exemplary embodiment of the present application, the MIMO radar is a millimeter wave radar, and the test signal is a chirp signal.

In an exemplary embodiment of the present application, the set target is a reflector placed in advance at a set distance in front of the MIMO radar, the reflector and the MIMO radar being placed in the same microwave dark room. In order to avoid electromagnetic wave interference of external environment and improve the accuracy of phase calibration as much as possible, in the embodiment, the MIMO radar is placed in a microwave darkroom, the microwave darkroom is used for simulating a free space environment, wave absorbing materials are paved on each surface of the inner side of a shielding structure of the microwave darkroom, and all reflected waves (including diffracted waves and scattered waves) can be reduced to the minimum. In addition, the present embodiment also uses a reflector placed in front of the MIMO radar in advance to reflect the test signal transmitted at the time of calibration of the MIMO radar, generating an echo signal to be detected. The reflector can be a corner reflector formed by combining corner reflectors, and the corner reflector can focus the energy of radar echo, so that electromagnetic energy incident in different directions can be returned to a radar antenna more, and the intensity of echo signals is enhanced. The distance between the reflector and the MIMO radar is related to the spectrum peak position in the distance dimension after the MIMO radar mixes, samples and 2D-FFT is carried out on the received signal, and the position range of the spectrum peak can be approximately determined by setting the distance, so that the target searching time during target detection is shortened, and the efficiency of transmitting phase calibration is improved.

In an exemplary embodiment of the present application, phases to be measured of the plurality of transmitting channels are uniformly configured according to a preset phase table of the MIMO radar, and the plurality of phases to be measured configured for each transmitting channel are the same; or alternatively

The phases that can be transmitted by the MIMO radar are limited, and for performing the calibration of the transmission phases, a part of the phases that can be transmitted may be selected as the phases to be measured of each transmission channel. For a plurality of transmission channels, in order to avoid leakage between the channels, the target angles in operation are different, and for example, a MIMO radar of 4 transmission channels is assumed to include a first transmission channel, a second transmission channel, a third transmission channel, and a fourth transmission channel, and the target angles in operation of the 4 transmission channels are 0 °,90 °, 180 °, and 270 °, respectively. The transmitting phase calibration method of the embodiment needs to find a phase to be measured, of which the corresponding measured phase is closest to the working phase, for each transmitting channel, and stores the phase to be measured, and the phase to be measured is used in working. Thus, in an example, the 4 transmit channels may be uniformly configured with phases to be measured, where the phases to be measured may be all angles traversed by a step of approximately 0.5 ° in a 360 ° range, which is easier and more convenient to implement. In another example, the target phases of the 4 transmitting channels may be individually set, for example, for a first transmitting channel, a more dense phase to be measured may be configured near 0 ° and for a second transmitting channel, a more dense phase to be measured may be configured near 90 °, and so on, where it is possible to find a phase to be measured whose corresponding measured phase is closer to the working phase from all possible phases. In the above example, one target phase of one transmission channel is taken as an example, but one transmission channel may have more than 2 target phases, and the phases to be measured may be respectively configured near each target phase.

In an exemplary embodiment of the present application, a plurality of phases to be measured configured for each transmission channel are the same;

In an example of the present embodiment, a MIMO radar having 4 transmission channels and 4 reception channels is taken as an example. Prior to calibration, a predetermined phase table (comprising a plurality of phases to be measured configured for each transmit channel) is stored in memory. After calibration is started, each phase to be measured (i.e., each phase point) in the phase table is set as the transmission phase of a plurality of transmission channels in a traversal manner, and then the 4t4r TDM-MIMO waveform of the phase point is transmitted, as shown in fig. 6, as the waveform of the single-phase point of the single frame transmitted by the transmission channels in this embodiment 4. The frame signal comprises N groups of test signals, each group of test signals comprises 4 test signals transmitted by the transmission channels in a time-sharing way, and the transmission phases of the test signals are the same and are the same phase to be tested. The waveform emitted by the mode can be calibrated on a plurality of emission channels simultaneously, and the method is simple to realize and high in efficiency.

In an exemplary embodiment of the present application, the detecting the phase of the echo signal generated after the test signal is reflected by the set target to obtain the measured phase corresponding to the phase to be measured includes: and respectively carrying out target search based on the received signals of a plurality of receiving channels of the MIMO radar, acquiring phases of the echo signals received by the receiving channels, and taking the acquired phases as measured phases corresponding to the phases to be measured.

The plurality of transmit channels may transmit test signals simultaneously, but subsequent calibration is performed separately, so that subsequent calibration is described herein as a transmit channel. The test signal transmitted by the transmitting channel is reflected by a set target to generate an echo signal, the receiving signals of a plurality of receiving channels are preprocessed (including but not limited to mixing, sampling, 2D-FTT and the like) to generate 2D-FFT data, the target position is determined by searching the spectrum peak position on the distance dimension and the speed dimension, and the phase of the 2D-FFT data (complex signal) at the target position is extracted, so that the phase of the echo signal is obtained. Taking 4-transmit 4-receive MIMO radar as an example, for each phase to be detected, the 4 actually measured phases corresponding to the phase to be detected may be obtained by performing signal processing on the received signals of the 4 receiving channels.

In an exemplary embodiment of the present application, the target search is performed within a determined search range, which is determined according to distance information in a transmit phase calibration command received by the MIMO radar or according to configuration information of the MIMO radar. Since the distance between the set target and the MIMO radar is known and there is a correspondence between the distance and the index of the 2D-FTT data, a range of 2D-FTT data to be searched can be determined according to the distance, so that the efficiency of phase calibration can be improved. On one hand, the distance information can be carried in a transmitting phase calibration command sent by a user, so that the distance can be flexibly adjusted; on the other hand, the distance information or the index range may be stored in advance as configuration information in the MIMO radar, and may be arranged at a desired distance when the reflectors, which are the setting targets, are arranged.

In an exemplary embodiment of the present application, determining a phase to be measured, of which the corresponding measured phase is closest to the target phase, from the plurality of phases to be measured includes:

And determining a phase to be measured with the minimum phase difference, wherein the determined phase to be measured is the phase to be measured, of which the corresponding measured phase is closest to the target phase, in the plurality of phases to be measured.

In this embodiment, the measured phase is preprocessed, so that possible data errors can be corrected. For example, when the range of the transmission phase is set to 0 to 360 °, if the acquired measured phase exceeds this range, the measured phase can be returned to a reasonable range by unwrapping the phase. For example, if a measured phase before the preprocessing is 380 °, a difference obtained by subtracting 360 ° (2pi) from the measured phase may be used as a measured phase after the unwrapping of the unwrapped phase; for another example, a measured phase before preprocessing is-30 °, then the sum of the measured phase plus 360 ° (2pi) can be used as a measured phase after unwrapping; if a measured phase before the pretreatment is 150 degrees, the measured phase after the unwrapping of the unwrapped phase is unchanged and still 150 degrees.

In this embodiment, the smaller the phase difference between the measured phase and the target phase is, the closer the measured phase is to the target phase, and therefore, the measured phase with the smallest phase difference represents the measured phase closest to the target. The measured phase is stored in a flash memory as a transmission phase used when the transmission channel is to transmit a signal having the target phase.

In an example of this embodiment, the preprocessing the plurality of measured phases corresponding to the phase to be measured further includes: and carrying out 0-deviation processing on each measured phase corresponding to the phase to be measured according to the following formula:

Ps_i'＝Ps_i-Ps_0-i+Pd₀，i＝1,2,…,I

For a MIMO radar, the deviations of the measured angles obtained in different receiving channels are often different with respect to the same angle to be measured. However, for the same receiving channel, the deviations between different angles to be measured and their corresponding measured angles may have the same tendency, such as smaller or larger. In this example, for each receiving channel, based on a certain reference angle (i.e., an angle to be measured as a reference) and a deviation between measured angles obtained from the receiving channel, the measured angles obtained from the receiving channel corresponding to other angles to be measured are corrected, so that the overall deviation of the measured angles obtained from the same receiving channel is corrected. The reference phase is, for example, 45 °, 135 °, 225 °, or 315 °. At these angles, the energy of the test signal is greater and the detection result is more reliable. For example, with reference to 45 ° (pd0=45°), assuming that the test signal is transmitted with reference to 45 ° (ps0-1=41°) based on the measured phase acquired by the first receiving channel, and with reference to 30 ° (psi=28°) based on the measured phase acquired by the first receiving channel, the measured phase (28 °) corresponding to the measured phase (30 °) is changed to Psi' =psi-ps0-i+pd0=28 ° -41 ° +45 ° =32° after 0 offset correction. It is easy to understand that, for the reference phase, the actual measurement angle after the 0-deviation correction changes to the reference phase itself, and the deviation between the two is 0. In the phase unwrapping process of the embodiment, the measured phase after the 0-offset process is unwrapped, and the 0-offset process can unify a reference coordinate system, that is, uses a reference point as a reference, so that the subsequent phase unwrapping process is facilitated, and the measured phase falls into a set phase range.

In an example of this embodiment, the method further includes: after transmitting a test signal for each phase to be tested in a plurality of phases to be tested, taking the phase to be tested as the transmitting phase of the transmitting channel, acquiring the amplitude of the echo signal received by each of the plurality of receiving channels in addition to the phase of the echo signal received by each of the plurality of receiving channels; the preprocessing of the measured phases corresponding to the phase to be measured further includes: the screening process of the measured phases is performed as follows: and searching echo signals with the amplitude smaller than a set amplitude threshold value in the echo signals received by the receiving channels, and deleting the searched phases of the echo signals from a plurality of measured phases corresponding to the phases to be detected.

According to the method, based on the amplitude of the signal, one-time screening is conducted on the obtained actual measurement phase, the phase of the echo signal with the amplitude smaller than the corresponding threshold value is deleted from the actual measurement phase corresponding to the phase to be measured, the error phase obtained by misidentifying the echo signal due to noise interference and the like can be avoided, and the accuracy of transmitting phase calibration can be improved through the screening based on the amplitude. The filtering process of this example is performed first after the preprocessing is started, and thus, subsequent redundant operations can be avoided, but the filtering process is not limited thereto.

In an example of this embodiment, the calculating, based on the preprocessed measured phase corresponding to the phase to be measured, a phase difference between the measured phase corresponding to the phase to be measured and the target phase may be performed in the following manner:

One way is: averaging all measured phases corresponding to the preprocessed phase to be detected; and calculating a difference between the average value and the target phase, and taking an absolute value of the difference as the phase difference; for example, when the second transmitting channel works, the target phase is 90 degrees, the 3 phases to be detected are 89 degrees, 90 degrees and 91 degrees, the actual measured phases corresponding to the 88 degrees of the preprocessed phases to be detected are 87 degrees, 89 degrees and 91 degrees, the average value is 89 degrees, and the absolute value of the difference between the average value and the target phase is 1 degree; the preprocessed measured phases with 90 degrees correspond to the measured phases with 86 degrees, 89 degrees and 87 degrees, the average value is 87.3, and the absolute value of the difference between the average value and the target phase is 2.7 degrees; the measured phase corresponding to the preprocessed phase to be detected of 91 degrees is 87 degrees, 91 degrees and 94 degrees, the average value is 90.7 degrees, and the absolute value of the difference between the average value and the target phase is 0.7 degrees. The phase to be measured of the 3 phases to be measured, which corresponds to the measured phase closest to the target phase, is 91 DEG, and when a signal with the target phase of 90 DEG is to be transmitted, the signal is transmitted by taking 91 DEG as the transmission phase.

Another way is: subtracting the target phase from all measured phases corresponding to the preprocessed phase to be detected respectively, determining the difference with the largest absolute value in the obtained differences, and taking the absolute value of the determined difference as the phase difference. Still based on the data, the target phase of the second transmitting channel in operation is 90 degrees, the 3 phases to be detected are 89 degrees, 90 degrees and 91 degrees, the measured phase corresponding to the 88 degrees of the phase to be detected after pretreatment is 87 degrees, 89 degrees and 91 degrees, the largest absolute value difference in the differences between the 3 measured phases and the target phase is-3 degrees, and the phase difference is 3 degrees; the preprocessed measured phases with 90 degrees correspond to the measured phases with 86 degrees, 89 degrees and 87 degrees, the difference with the largest absolute value in the differences between the 3 measured phases and the target phase is-4 degrees, and the phase difference is 4 degrees; the measured phase corresponding to the preprocessed phase to be detected of 91 degrees is 87 degrees, 91 degrees and 94 degrees, the largest absolute value difference in the differences between the 3 measured phases and the target phase is 4 degrees, and the phase difference is 4 degrees. The phase to be measured of the 3 phases to be measured, which corresponds to the measured phase closest to the target phase, is 89 DEG, and when a signal with the target phase of 90 DEG is to be transmitted, the signal is transmitted by taking 89 DEG as the transmission phase.

The method is not limited to the above two methods, one is to evaluate the proximity degree of the measured phase and the target phase by the difference between the average value of the measured phase and the target phase, and the other is to evaluate the proximity degree of the measured phase and the target phase by the maximum difference between the measured phase and the target phase, and other algorithms capable of calculating the errors between a plurality of measured phases and the target phase can be used.

According to the method for automatically calibrating the transmitting phase of the MIMO radar, the transmitting phase of the radar is directly calibrated by combining the actual working waveform of the radar, the calibration accuracy is high, and leakage and inter-channel coupling influence caused by inaccurate transmitting phase can be effectively reduced. In addition, the method is simple in algorithm, small in calculated amount and small in occupied space. And the operation is simple and quick, and the user can directly send a calibration instruction to the MIMO radar, so that the calibration can be completed within 2 seconds.

An embodiment of the application provides a method for automatically calibrating a transmitting phase, which is applied to a vehicle-mounted millimeter wave MIMO radar, wherein the MIMO radar comprises a 4-transmission 4-reception (4T 4R) millimeter wave radar chip, 4 transmitting antennas and 4 receiving antennas. As shown in fig. 7, the millimeter wave radar chip 9 includes a transmitting module 93, a receiving module 95, and a signal processing module 97, and may further include other modules. Wherein:

The transmitting module 93 includes 4 transmitting channels (T1, T2, T3 and T4), corresponding to the 4 transmitting antennas, configured to generate a transmitting waveform, modulate the transmitting waveform to an operating frequency band (in a frequency band of 76GHz to 81 GHz), and send the transmitting waveform to the transmitting antennas for transmission.

The receiving module 95 includes 4 receiving channels (R1, R2, R3, R4), and corresponds to 4 receiving antennas, and is configured to process (such as amplifying, mixing, filtering, and down-converting to a baseband signal) a received signal (mainly including an echo signal generated by a test signal after being reflected by a set target), and send the processed signal to the signal processing module;

The signal processing module 97 performs a/D sampling, 1D-FFT, 2D-FFT, coherent integration (NCI) or incoherent integration (NCI), constant False alarm detection (CFAR) or DOA on the received signal, so as to detect the target and estimate parameters (distance, speed, azimuth, pitch angle, signal-to-noise ratio, etc.) of the target.

Referring to fig. 7, when the millimeter wave radar chip 9 operates, the transmitting module 93 generates a transmitting waveform according to the configuration, modulates to a specified frequency band to generate a transmitting signal, and sends the transmitting signal to the transmitting antenna, which sends the signal out. The transmitting signal is reflected by the target to generate an echo signal, the receiving antenna receives the echo signal and sends the echo signal to the receiving module 95, the receiving module 95 processes the received signal to obtain the echo signal, the signal processing module 97 processes the echo signal to detect the target and estimate the target parameter, and finally sends the echo signal to the tracking end for application layer processing.

In this embodiment, the transmission phases of the 4 transmission channels of the MIMO radar are calibrated, and the overall flow is as shown in fig. 8, where the MIMO radar is first arranged in a darkroom, for example, a corner reflector of 10dBsm may be placed at a distance R in front of the radar.

After the MIMO radar is powered on, receiving a transmitting phase calibration command sent by a user, starting a transmitting phase automatic calibration function, and acquiring target distance information from command parameters;

the MIMO radar performs a transmit phase calibration procedure, and transmits test signals of single-frame single-phase site waveforms, specifically TDM-MIMO waveforms of 4T4R, with one phase point, i.e., one phase to be measured, as shown in fig. 6. The starting phase point of each transmission pulse (chirp signal) of each transmission channel in the same frame is the same;

The transmitted chirp signal waveform is reflected by a target to generate echo signals, and the MIMO radar generates 2D-FFT data after preprocessing the time line echoes of the received signals of a plurality of receiving channels;

after the target search is completed, extracting the amplitude and the phase of 2D-FFT data of the single-phase site target (namely the amplitude and the phase of the echo signal), and then processing the single-frame single-phase site extraction result (comprising removing 0 offset, unwrapping the phase and averaging each receiving channel by taking 45 DEG as a reference), wherein the processing result (the actual measurement phase corresponding to the single phase to be detected) is stored in a memory;

Traversing the preset phase table in sequence according to the mode, wherein one phase to be detected (also called as a phase point) is used for each frame until the whole preset phase table is traversed, and performing multi-frame optimizing processing, namely searching the optimal phase to be detected in the multi-frame processing result, namely searching the corresponding phase to be detected, which corresponds to the actually measured phase and is closest to the target phase;

The determined phase calibration result may be stored in a flash so that the radar operates normally using this phase. The embodiment of the application is simple and quick to operate, and can automatically complete calibration after 2s by directly sending an instruction to a target in a microwave dark room. The calibrated value is stored in a flash.

An embodiment of the present application further provides a transmit phase calibration apparatus, which is applied to a radar system, as shown in fig. 9, and includes a memory 50 and a processor 60, where the memory 50 stores a computer program, and the processor 60 can implement the transmit phase calibration method according to any embodiment of the present application when executing the computer program. The transmitting phase calibration device can be realized by a main processing chip and a transmitting chip shown in fig. 1, or a chip integrated with the main processing chip and the transmitting chip, or corresponding software and hardware in a chip integrated with an antenna after the main processing chip and the transmitting chip are integrated with each other.

The processor of the present embodiment may be a general-purpose processor, including a Central Processing Unit (CPU), a network processor (Network Processor NP), a microprocessor, etc., or may be other conventional processors; the processor may also be a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf programmable gate array (FPGA), discrete logic or other programmable logic device, discrete gate or transistor logic, discrete hardware components; combinations of the above are also possible. That is, the processor of the above-described embodiments may be any processing device or combination of devices that implements the methods, steps, and logic blocks disclosed in embodiments of the application. If embodiments of the present application are implemented, in part, in software, instructions for the software may be stored in a suitable non-volatile computer-readable storage medium and the instructions may be executed in hardware using one or more processors to implement the methods of embodiments of the present application.

An embodiment of the present application further provides a non-transitory computer readable storage medium storing a computer program, where the computer program is capable of implementing the transmit phase calibration method according to any embodiment of the present application when executed by a processor.

An embodiment of the present application further provides an integrated circuit, as shown in fig. 10, the integrated circuit includes a radio frequency module 2011, an analog signal processing module 2012, and a digital signal processing module 2013, which are sequentially connected, wherein:

the radio frequency module 2011 is configured to generate a radio frequency transmit signal and receive a radio frequency echo signal;

the analog signal processing module 2012 is configured to perform down-conversion processing on the rf echo signal to obtain an intermediate frequency signal; and

The digital signal processing module 2013 is configured to perform analog-to-digital conversion on the intermediate frequency signal to obtain a digital signal; the digital signal processing module is further configured to execute the transmit phase calibration method according to any embodiment of the present application to achieve transmit phase calibration. In particular, the method may be implemented by a processor in the integrated circuit executing a transmit phase calibration program stored in a memory in the integrated circuit.

In an alternative embodiment, the integrated circuit may be a millimeter wave radar chip. The kind of digital functional modules in the integrated circuit can be determined according to the actual requirements. For example, in millimeter wave radar chips, the data processing module may be used for obtaining information such as distance dimension doppler transform, velocity dimension doppler transform, constant false alarm detection, direction of arrival detection, point cloud processing, etc., for obtaining distance, angle, velocity, shape, size, surface roughness, and dielectric characteristics of the target. Alternatively, the integrated circuit may be AiP (Antenna-In-Package) Chip structure, aoP (Antenna-On-Package) Chip structure, or AoC (Antenna-On-Chip) Chip structure, or the like.

In an alternative embodiment, when the integrated circuit is in a chip structure, at least two chips may be used to form a cascade structure to form a radar system with a larger antenna aperture and a stronger processing capability, which is not described herein for simplicity, but it should be understood that the technology that a person skilled in the art should learn based on the disclosure of the present application is included in the scope of the disclosure of the present application.

The present application also provides a radio device, as shown in fig. 11, comprising: a carrier 4; the integrated circuit 5 according to any of the embodiments of the present application is disposed on the carrier 4; an antenna 6 disposed on the carrier 4, or the antenna 6 and the integrated circuit 5 are integrated into a single device disposed on the carrier 4 (i.e. the antenna may be an antenna disposed in an AiP, aoP or AoC structure); wherein the integrated circuit 5 is connected to the antenna 6 (i.e. the sensor chip or the integrated circuit is not integrated with an antenna, such as a conventional SoC, etc.), and is configured to transmit the radio frequency transmit signal and receive the radio frequency echo signal. The carrier may be a printed circuit board PCB (e.g., a development board, a number board, or a motherboard of a device), and the first transmission line may be a PCB trace.

The application also provides a terminal device, comprising: an equipment body; and a radio device according to any of the embodiments of the present application provided on the apparatus body; wherein the radio is arranged to enable target detection and/or communication to provide reference information to the operation of the device body.

On the basis of the above-described embodiments, in an alternative embodiment of the present application, the radio device may be provided outside the apparatus body or inside the apparatus body, while in another alternative embodiment of the present application, the radio device may be provided partly inside the apparatus body and partly outside the apparatus body. The embodiments of the present application are not limited thereto, and may be specifically determined as appropriate.

In an alternative embodiment, the device body may be a component or product for applications such as smart cities, smart homes, transportation, smart homes, consumer electronics, security monitoring, industrial automation, in-cabin detection (e.g., smart cabins), medical devices, and health care. For example, the device body may be an intelligent transportation device (such as an automobile, a bicycle, a motorcycle, a ship, a subway, a train, etc.), a security device (such as a camera), a liquid level/flow rate detection device, an intelligent wearable device (such as a bracelet, glasses, etc.), an intelligent home device (such as a sweeping robot, a door lock, a television, an air conditioner, an intelligent lamp, etc.), various communication devices (such as a mobile phone, a tablet computer, etc.), etc., a barrier gate, an intelligent traffic indicator, an intelligent indicator, a traffic camera, various industrial mechanical arms (or robots), etc., and may also be various instruments for detecting vital sign parameters and various devices carrying the instruments, such as an in-cabin vital sign detection, an indoor personnel monitoring, an intelligent medical device, a consumer electronic device, etc.

It should be noted that the radio device may implement functions such as object detection and/or communication by transmitting and receiving radio signals, so as to provide detection object information and/or communication information to the device body, thereby assisting and even controlling the operation of the device body. For example, when the above-mentioned device body is applied to an advanced driving assistance system (i.e., ADAS), a radio device (e.g., millimeter wave radar) as an in-vehicle sensor may assist the ADAS system to implement application scenarios such as adaptive cruise, automatic braking assistance (i.e., AEB), blind spot detection early warning (i.e., BSD), auxiliary lane change early warning (i.e., LCA), reverse auxiliary early warning (i.e., RCTA), parking assistance, rear vehicle warning, anti-collision (e.g., door opening early warning/anti-collision, etc.), pedestrian detection, etc.

Those of ordinary skill in the art will appreciate that all or some of the steps, systems, functional modules/units in the apparatus, and methods disclosed above may be implemented as software, firmware, hardware, and suitable combinations thereof. In a hardware implementation, the division between the functional modules/units mentioned in the above description does not necessarily correspond to the division of physical components; for example, one physical component may have multiple functions, or one function or step may be performed cooperatively by several physical components. Some or all of the components may be implemented as software executed by a processor, such as a digital signal processor or microprocessor, or as hardware, or as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on computer readable media, which may include computer storage media (or non-transitory media) and communication media (or transitory media). The term computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data, as known to those skilled in the art. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital Versatile Disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by a computer. Furthermore, as is well known to those of ordinary skill in the art, communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media.

Claims

1. A method of transmit phase calibration, comprising: performing transmit phase calibration for a plurality of transmit channels of the MIMO radar, the transmit phase calibration for each of the transmit channels comprising:

2. The method of claim 1, wherein the step of determining the position of the substrate comprises,

The MIMO radar supports transmission of DDM-MIMO waveform signals over the plurality of transmit channels.

3. The method of claim 1, wherein the step of determining the position of the substrate comprises,

The phases to be detected of the multiple transmitting channels are uniformly configured according to a preset phase table of the MIMO radar, and the multiple phases to be detected configured for each transmitting channel are the same; or alternatively

4. The method of claim 1, wherein the step of determining the position of the substrate comprises,

The multiple phases to be tested configured for each emission channel are the same;

5. The method of claim 1, wherein the step of determining the position of the substrate comprises,

The detecting the phase of the echo signal generated after the test signal is reflected by the set target to obtain the measured phase corresponding to the phase to be measured comprises the following steps: and respectively carrying out target search based on the received signals of a plurality of receiving channels of the MIMO radar, acquiring phases of the echo signals received by the receiving channels, and taking the acquired phases as measured phases corresponding to the phases to be measured.

6. The method of claim 5, wherein the step of determining the position of the probe is performed,

The target search is performed within a determined search range, which is determined according to distance information in a transmit phase calibration command received by the MIMO radar or according to configuration information of the MIMO radar.

7. The method of claim 5, wherein the step of determining the position of the probe is performed,

Determining a phase to be measured of which the corresponding measured phase is closest to the target phase from the plurality of phases to be measured, including:

8. The method of claim 7, wherein the step of determining the position of the probe is performed,

The preprocessing of the measured phases corresponding to the phase to be measured further includes: and carrying out 0-deviation processing on each measured phase corresponding to the phase to be measured according to the following formula:

Ps_i'＝(Ps_i-Ps_0-i)+Pd₀，i＝1,2,…,I

9. The method of claim 8, wherein the reference phase is 45 °, 135 °, 225 °, or 315 °.

10. The method of claim 7, wherein the step of determining the position of the probe is performed,

The method further comprises the steps of: after transmitting a test signal for each phase to be tested in a plurality of phases to be tested, taking the phase to be tested as the transmitting phase of the transmitting channel, acquiring the amplitude of the echo signal received by each of the plurality of receiving channels in addition to the phase of the echo signal received by each of the plurality of receiving channels;

11. The method of claim 7, wherein the step of determining the position of the probe is performed,

The calculating the phase difference between the measured phase corresponding to the phase to be measured and the target phase based on the measured phase corresponding to the phase to be measured after the preprocessing includes:

12. The method of claim 1, wherein the step of determining the position of the substrate comprises,

The MIMO radar is a millimeter wave radar, and the test signal is a chirp signal;

13. A transmit phase calibration apparatus comprising a processor and a memory storing a computer program, wherein the processor is capable of implementing a transmit phase calibration method as claimed in any one of claims 1 to 12 when executing the computer program.

14. A non-transitory computer readable storage medium storing a computer program, characterized in that the computer program when executed by a processor implements the transmit phase calibration method of any one of claims 1 to 12.

15. An integrated circuit is characterized by comprising a radio frequency module, an analog signal processing module and a digital signal processing module which are connected in sequence;

the radio frequency module is arranged to generate a radio frequency transmitting signal and receive a radio frequency echo signal;

The analog signal processing module is used for performing down-conversion processing on the radio frequency echo signals to obtain intermediate frequency signals; and

The digital signal processing module is configured to perform analog-to-digital conversion on the intermediate frequency signal to obtain a digital signal;

wherein the digital signal processing module is further arranged to perform the method of any of claims 1-12 to achieve a transmit phase calibration.

16. The integrated circuit of claim 15, wherein the integrated circuit is a millimeter wave chip.

17. A radio device, comprising:

A carrier;

An integrated circuit as claimed in claim 15 or 16, disposed on a carrier;

the antenna is arranged on the supporting body, or the antenna and the integrated circuit are integrated into a whole device and arranged on the supporting body;

The integrated circuit is connected with the antenna and is arranged to transmit the radio frequency transmission signal and/or receive the radio frequency echo signal.

18. A terminal device, comprising:

An equipment body; and

The radio device of claim 17 disposed on the device body;

wherein the radio is arranged to enable target detection and/or communication to provide reference information to the operation of the device body.