MIMO signal channel separation and reconstruction method and system for millimeter wave radar

Abstract

The invention discloses an MIMO signal channel separation and reconstruction method and system for a millimeter wave radar. The method comprises the steps of obtaining echo signals of the millimeter wave radar and converting the echo signals into a plurality of 4D matrixes; performing fast Fourier transform based on the 4D matrix to obtain a transformed 4D matrix and distance-Doppler spectrum data; distance-Doppler unit index value pairs corresponding to all peak values are obtained based on the distance-Doppler spectrum data; all the distance-Doppler unit index value pairs are substituted into the transformation 4D matrix, and a plurality of MIMO signal channel data two-dimensional matrixes are correspondingly obtained; constructing a channel reconstruction matrix based on the virtual array surface features; and filling the MIMO signal channel data two-dimensional matrix into the channel reconstruction matrix according to a specific sequence to obtain a non-sparse channel reconstruction matrix. The MIMO signal channel separation efficiency and accuracy are improved, and the processing efficiency and robustness of diversified and complex radar data are further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of MIMO radar target detection, and more particularly to a MIMO signal channel separation and reconstruction method and system for millimeter wave radar. Background Art

[0002] Millimeter-wave radar refers to radar operating in the millimeter-wave frequency band (30GHz to 300GHz). In the sensor field, compared to sensors such as lidar and cameras, millimeter-wave radar has better spatial resolution, penetration, anti-interference capabilities, and all-weather operation capabilities, and has broad application prospects in cutting-edge low-altitude economic detection. Multiple-input multiple-output (MIMO) radar is a radar system that integrates multiple transmitters and multiple receivers. MIMO technology can improve radar performance, but channel separation of MIMO signals is a key issue.

[0003] Problems in existing technologies include: (1) channels are not effectively separated, resulting in low accuracy in actual angle measurement, which can lead to detection errors; (2) insufficient robustness, which cannot meet the requirements of fast angle measurement and spectral imaging for all radar arrays, especially two-dimensional antenna array radars; (3) lack of intuitiveness, making implementation difficult;

[0004] Therefore, how to improve the efficiency and accuracy of MIMO signal channel separation, and thereby improve the processing efficiency and robustness of diverse and complex radar data, is an urgent problem that those skilled in the art need to solve. Summary of the Invention

[0005] In view of this, the present invention provides a MIMO signal channel separation and reconstruction method and system for millimeter-wave radar, which improves the efficiency and accuracy of MIMO signal channel separation, thereby improving the processing efficiency and robustness of diverse and complex radar data.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A MIMO signal channel separation and reconstruction method for millimeter wave radar, comprising:

[0008] Obtain the echo signal of the millimeter-wave radar and convert it into multiple 4D matrices;

[0009] Performing a fast Fourier transform based on the 4D matrix to obtain a transformed 4D matrix and range-Doppler spectrum data;

[0010] Obtaining range-Doppler unit index value pairs corresponding to all peaks based on the range-Doppler spectrum data;

[0011] Substituting all the range-Doppler unit index value pairs into the transformed 4D matrix, and correspondingly obtaining a plurality of MIMO signal channel data two-dimensional matrices;

[0012] Constructing a channel reconstruction matrix based on the virtual array features;

[0013] The MIMO signal channel data two-dimensional matrix is ​​filled into the channel reconstruction matrix in a specific order to obtain a non-sparse channel reconstruction matrix.

[0014] Preferably, the echo signal acquisition method is:

[0015] The transmitting antenna of the millimeter wave radar sequentially transmits electromagnetic wave signals according to channels;

[0016] The electromagnetic wave signal is reflected back by the detector as a frequency sweep signal;

[0017] The frequency sweep signal is received by the receiving antenna of the millimeter wave radar, and the echo signal is obtained after mixing and filtering.

[0018] Preferably, the 4D matrix acquisition method is:

[0019] Extracting a preset number of signed integer data based on the echo signal as original data;

[0020] Based on the first half of the original data as real data;

[0021] Based on the second half of the original data as imaginary data;

[0022] generating complex data based on the combination of the real data and the imaginary data;

[0023] The complex data are sorted and reorganized to obtain a plurality of 4D matrices.

[0024] Preferably, the sorting and reorganization specifically includes:

[0025] The complex data are sorted and reorganized according to the number of data frames, the number of frequency sweep signals between each frame, the number of frequency sampling points, the number of radar transmitting channels and the number of radar receiving channels.

[0026] Preferably, the channel reconstruction matrix construction method is:

[0027] Obtaining the number of transmitting antennas of the transmitting antenna in azimuth and elevation directions;

[0028] Obtaining the number of receiving antennas of the receiving antenna in azimuth and elevation directions;

[0029] Based on the number of transmitting antennas and the number of receiving antennas and according to the characteristics of the synthetic array of the partial virtual aperture of the radar antenna, a minimum rectangle including the virtual array surface is constructed as the channel reconstruction matrix.

[0030] Preferably, obtaining the non-sparse channel reconstruction matrix specifically includes:

[0031] The two-dimensional matrix of MIMO signal channel data includes all virtual channel data;

[0032] Based on each of the virtual channel data being filled into the corresponding geometric position in the channel reconstruction matrix in a specific order, the position without data filling is directly set to zero, thereby obtaining the non-sparse channel reconstruction matrix.

[0033] Preferably, filling the channel reconstruction matrix in a specific order is specifically as follows:

[0034] Numbering the transmitting antennas based on the transmission order of the transmitting antennas to obtain a transmission order number;

[0035] Numbering the receiving antennas based on the receiving order of the receiving antennas to obtain a receiving order number;

[0036] Based on the numbers of all virtual channel data in the two-dimensional matrix of the MIMO signal channel data, the channel reconstruction matrix is ​​filled according to the corresponding transmission sequence numbers and the reception sequence numbers.

[0037] Preferably, the method for obtaining the virtual channel data number is:

[0038] Based on the mth transmitting antenna in the millimeter wave radar transmitting a signal with preset parameters, multiple receiving antennas sequentially number the received signals according to the positions of the receiving antennas to obtain the virtual channel data number.

[0039] Preferably, it also includes:

[0040] Performing a two-dimensional fast Fourier transform based on the non-sparse channel reconstruction matrix to obtain two-dimensional angular spectrum data;

[0041] Performing spectral imaging based on the amplitude of the two-dimensional angular spectrum data;

[0042] The position of the detector in the vertical plane is obtained based on the spectral imaging result.

[0043] A MIMO signal channel separation and reconstruction system for millimeter wave radar, comprising: a signal acquisition module, a signal processing module, an index value pair acquisition module, a channel data acquisition module and a channel reconstruction module;

[0044] The signal acquisition module is used to acquire the echo signal of the millimeter wave radar and convert it into multiple 4D matrices;

[0045] The signal processing module is used to perform fast Fourier transform based on the 4D matrix to obtain a transformed 4D matrix and range-Doppler spectrum data;

[0046] The index value pair acquisition module is used to obtain the range-Doppler unit index value pairs corresponding to all peaks based on the range-Doppler spectrum data;

[0047] The channel data acquisition module is used to bring all the range-Doppler unit index value pairs into the transformation 4D matrix to obtain multiple MIMO signal channel data two-dimensional matrices;

[0048] The channel reconstruction module is used to construct a channel reconstruction matrix based on the virtual array characteristics; fill the MIMO signal channel data two-dimensional matrix into the channel reconstruction matrix in a specific order to obtain a non-sparse channel reconstruction matrix.

[0049] Through the above technical solutions, it can be seen that compared with the existing technology, the present invention discloses a MIMO signal channel separation and reconstruction method and system for millimeter wave radar, which effectively realizes the MIMO signal channel separation in TDM mode, and considers the geometric structure of different radar antennas to solve the problem of MIMO signal channel separation and joint angular spectrum imaging based on two-dimensional array, with convenience and universality; the present invention makes full use of the acquired complex valued data, fully considers the geometric characteristics of the radar antenna array, improves the generalization ability of the MIMO signal channel separation program, and also enables it to better adapt and understand when processing diverse and complex radar data, thereby improving overall performance and robustness. The method proposed in the present invention can effectively separate MIMO multi-channel signals, improve the performance of millimeter wave radar, has high practical value, and provides a reference idea and practical path for the signal processing development of various millimeter wave radars. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0051] Figure 1 This is a flow chart of a MIMO signal channel separation and reconstruction method for millimeter wave radar provided by the present invention.

[0052] Figure 2 This is a structural schematic diagram of the echo signal acquisition device provided by the present invention.

[0053] Figure 3 This is a schematic diagram of the 4D matrix generation process provided by the present invention.

[0054] Figure 4 Schematic diagram of the process of constructing the non-sparse channel reconstruction matrix provided by the present invention.

[0055] Figure 5 This is a schematic diagram of the spectral imaging results provided by the present invention.

[0056] Figure 6 This is a schematic diagram of the structure of a MIMO signal channel separation and reconstruction system for millimeter wave radar provided by the present invention. DETAILED DESCRIPTION

[0057] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0058] Example 1

[0059] like Figure 1 As shown, an embodiment of the present invention discloses a MIMO signal channel separation and reconstruction method for millimeter wave radar, comprising:

[0060] Obtain the echo signal of the millimeter-wave radar and convert it into multiple 4D matrices;

[0061] Perform fast Fourier transform based on the 4D matrix to obtain the transformed 4D matrix and range-Doppler spectrum data;

[0062] Based on the range-Doppler spectrum data, the range-Doppler unit index value pairs corresponding to all peaks are obtained;

[0063] Substitute all the range-Doppler unit index value pairs into the transformation 4D matrix to obtain the corresponding two-dimensional matrices of multiple MIMO signal channel data;

[0064] Constructing a channel reconstruction matrix based on the virtual array features;

[0065] The two-dimensional matrix of MIMO signal channel data is filled into the channel reconstruction matrix in a specific order to obtain a non-sparse channel reconstruction matrix.

[0066] Example 2

[0067] The embodiment of the present invention discloses a MIMO signal channel separation and reconstruction method for millimeter wave radar, comprising:

[0068] Acquire the echo signal of the millimeter-wave radar and convert it into multiple 4D matrices.

[0069] Preferably, the echo signal acquisition method is:

[0070] The transmitting antenna based on the millimeter wave radar transmits electromagnetic wave signals in sequence according to the channel;

[0071] The electromagnetic wave signal is reflected back to the sweep signal through the detector;

[0072] The swept frequency signal is received by the receiving antenna of the millimeter wave radar, and the echo signal is obtained after mixing and filtering.

[0073] Preferably, Figure 2 As shown, the echo signal acquisition device includes: a PC device, a processor, a collector and a detector;

[0074] Among them, the PC device is the computer user end, which is used to control the start of the entire data acquisition, analyze the radar receiving signal and realize data visualization;

[0075] The processor is a data acquisition card and driver software, including a digital signal processor (DSP) and a field programmable gate array (FPGA). Through pre-cured programs, it transmits control signals to the back collector, sends waveform signals, and determines the signals emitted by the collector.

[0076] The collector is a millimeter-wave radar, which includes an antenna array and a radio frequency front end. It serves as a medium for sending and receiving electromagnetic wave signals. It is responsible for receiving control signals from the processor and sending electromagnetic wave signals to the detector.

[0077] The detector is a non-metallic bracket equipped with a corner reflector, which is used to assume the target, reflect the received electromagnetic wave signal and generate an echo signal.

[0078] Preferably, the echo signal acquisition device operates as follows: a PC is connected to a data collector, which is then connected to a processor. A control signal is sent from the PC to the data collector, initiating data acquisition. The processor transmits a pre-cured FMCW waveform signal to the data collector, which is the millimeter-wave radar. The millimeter-wave radar, operating in a TDM mode, transmits electromagnetic wave signals sequentially according to the transmission channel. Part of the chirp signal is reflected by the detector. The reflected signal, which contains all the information about the corner reflector, is received by the millimeter-wave radar's receiving antenna and transmitted back to the PC, generating a data file, namely the echo signal.

[0079] Preferably, Figure 3 As shown, the 4D matrix acquisition method is:

[0080] Extracting a preset number of signed integer data as raw data based on the echo signal;

[0081] Based on the first half of the original data as real data;

[0082] Based on the second half of the original data as imaginary data;

[0083] Generate complex data based on the combination of real data and imaginary data;

[0084] Based on the complex data, multiple 4D matrices are obtained by sorting and reorganizing.

[0085] Preferably, valid 16-bit signed integer data is extracted based on the echo signal as the original data, and the length of the original data is filesize; the first half of the data based on the original data is used as the real data I; the second half of the data based on the original data is used as the imaginary data Q; the lengths of the real data I and the imaginary data Q are both filesize / 2.

[0086] Preferably, the real data I and the imaginary data Q are combined by a complex function to generate complex data, and the complex data contains more data information.

[0087] Preferably, the sorting and reorganization specifically includes:

[0088] According to the number of data frames Nf, the number of sweep frequency signals between each frame Nc, the number of frequency sampling points Ns, the number of radar transmit channels numTx and the number of radar receive channels numRx, the obtained complex data are sorted and reorganized, and the format is converted into Nf 4D matrices [Nc, Ns, numTx, numRx].

[0089] Preferably, the 4D matrix of any frame is represented as:

[0090]

[0091] Among them, S represents the slope of the FMCW wave emitted by the radar, j represents the imaginary unit, and j satisfies 2 =-1, c represents the speed of light, f c Indicates the operating frequency, t s represents the sampling time, t c represents the sweep signal time, R represents the radial distance of the reflection point relative to the radar center, v represents the relative speed, represents the angle between the reflection point and the vertical plane where the radar center is located, θ represents the angle between the reflection point and the horizontal plane where the radar center is located, and d represents the distance between the radar antenna units.

[0092] A fast Fourier transform is performed based on the 4D matrix to obtain a transformed 4D matrix and range-Doppler spectrum data.

[0093] Preferably, based on the errors in the millimeter-wave radar itself in terms of manufacturing process, signal propagation and environmental factors, this application will use the pre-saved calibration data to calibrate the Nf time-domain 4D matrices [Nc, Ns, numTx, numRx] generated above to improve the accuracy of angle detection. Each millimeter-wave radar only requires one set of calibration data.

[0094] Preferably, the 4D matrix includes four dimensions, wherein the first dimension represents the distance dimension, the second dimension represents the Doppler dimension, the third dimension represents the transmission channel dimension, and the fourth dimension represents the receiving channel dimension.

[0095] Preferably, a fast Fourier transform is performed along the range dimension and the Doppler dimension based on the calibrated 4D matrix to obtain a transformed 4D matrix and range-Doppler spectrum data. The 4D matrix after fast Fourier transform processing is a frequency domain 4D complex matrix.

[0096] Preferably, according to the established algorithm, the 4D matrix S of any frame echo (t s ,t c ,numTx,numRx) perform fast Fourier transform along the first and second dimensions to obtain the range-Doppler data S RDMap , which can be expressed as:

[0097]

[0098] Among them, f r Indicates the distance frequency, f v Indicates the Doppler frequency.

[0099] Based on the range-Doppler spectrum data, the range-Doppler unit index value pairs corresponding to all peaks are obtained.

[0100] Preferably, a coherent accumulation operation is performed based on the range-Doppler data to enhance the signal-to-noise ratio, and peak detection is performed on the data after the accumulation operation to obtain a range-Doppler unit index value pair at the peak.

[0101] Preferably, in this embodiment, a 2D Constant False Alarm Rate (2D CFAR) algorithm with a cross sliding window is used for peak detection. Common CFARs include mean-value CFAR (CA, SO, GO) and sequential CFAR (OS). This embodiment uses the CA-CFAR algorithm.

[0102] Substitute all the range-Doppler unit index value pairs into the transformation 4D matrix to obtain corresponding two-dimensional matrices of multiple MIMO signal channel data.

[0103] Preferably, all the range-Doppler unit index value pairs obtained above are substituted into the transformation 4D matrix, and each range-Doppler unit index value pair can obtain a MIMO signal channel data two-dimensional matrix [numTx, numRx], which contains all numTx×numRx virtual channel data.

[0104] The channel reconstruction matrix is ​​constructed based on the virtual array features.

[0105] Preferably, the channel reconstruction matrix construction method is:

[0106] Obtain the number of transmitting antennas in azimuth and elevation directions;

[0107] Get the number of receiving antennas in azimuth and elevation directions;

[0108] Based on the number of transmitting antennas and receiving antennas and the characteristics of the synthetic array of the partial virtual aperture of the radar antenna, a minimum rectangle including the virtual array surface is constructed as the channel reconstruction matrix.

[0109] Preferably, the corresponding numbers of transmitting antennas Tx_azi and Tx_ele of the transmitting antenna in the azimuth and elevation directions are obtained; the corresponding numbers of receiving antennas Rx_azi and Rx_ele of the receiving antenna in the azimuth and elevation directions are obtained; based on Tx_azi, Tx_ele, Rx_azi and Rx_ele and according to the characteristics of the partial virtual aperture synthetic array of the radar antenna, a minimum rectangle including the virtual array surface is constructed as the channel reconstruction matrix [Tx_azi+Rx_azi-1, Tx_azi+Rx_azi-1].

[0110] The two-dimensional matrix of MIMO signal channel data is filled into the channel reconstruction matrix in a specific order to obtain a non-sparse channel reconstruction matrix.

[0111] Preferably, Figure 4 As shown, the non-sparse channel reconstruction matrix is ​​obtained, which specifically includes:

[0112] The two-dimensional matrix [numTx, numRx] of MIMO signal channel data is the snapshot matrix;

[0113] The snapshot matrix includes all virtual channel data;

[0114] Each virtual channel data in the snapshot matrix is ​​filled into the corresponding geometric position in the channel reconstruction matrix in a specific order. Positions without data are directly set to zero to obtain a non-sparse channel reconstruction matrix. This avoids the limitations of sparse matrix processing, improves imaging accuracy, and accelerates calculation speed, thereby effectively achieving MIMO signal channel separation and reconstruction.

[0115] Preferably, filling in the channel reconstruction matrix in a specific order is specifically as follows:

[0116] Numbering the transmitting antennas based on the transmission order of the transmitting antennas to obtain a transmission order number;

[0117] Numbering the receiving antennas based on the receiving order of the receiving antennas to obtain a receiving order number;

[0118] Based on the MIMO signal channel data two-dimensional matrix, that is, all virtual channel data numbers in the snapshot matrix are filled into the channel reconstruction matrix according to the corresponding transmission sequence number and reception sequence number.

[0119] Preferably, the millimeter wave radar assumes that there are numTx transmitting antennas and numRx receiving antennas, and the channel signal transmitted by the mth transmitting antenna (m=1, 2, 3, ..., numTx, numbered in the order of transmitter transmission) and received by the nth receiving antenna (n=1, 2, 3, ..., numRx, numbered in the order of receiver position) is recorded as mTnR.

[0120] Preferably, each transmitting antenna transmits a frequency sweep signal once according to preset parameters, and each receiving antenna receives the reflected signal simultaneously, and the transmitted signals are orthogonally separable through a time division multiplexing (TDM) mode.

[0121] Preferably, the method for obtaining the virtual channel data number is:

[0122] Based on the mth transmitting antenna in the millimeter-wave radar transmitting a signal with preset parameters, multiple receiving antennas number the received signals from (m-1)×numRx+1 to m×numRx according to the receiving antenna position to obtain the virtual channel data number.

[0123] Preferably, it also includes:

[0124] Perform two-dimensional fast Fourier transform based on the non-sparse channel reconstruction matrix to obtain two-dimensional angular spectrum data;

[0125] Spectral imaging based on the amplitude of two-dimensional angular spectrum data;

[0126] The position of the detector in the vertical plane is obtained based on the spectral imaging results.

[0127] Preferably, spectral imaging is performed based on the obtained non-sparse channel reconstruction matrix, such as Figure 5 As shown, the two brightest white spots more accurately show the positions of the two corner reflectors in the vertical plane.

[0128] Example 3

[0129] like Figure 6As shown, a MIMO signal channel separation and reconstruction system for millimeter wave radar includes: a signal acquisition module, a signal processing module, an index value pair acquisition module, a channel data acquisition module and a channel reconstruction module;

[0130] The signal acquisition module is used to obtain the echo signal of the millimeter wave radar and convert it into multiple 4D matrices;

[0131] A signal processing module is used to perform fast Fourier transform based on the 4D matrix to obtain a transformed 4D matrix and range-Doppler spectrum data;

[0132] An index value pair acquisition module is used to obtain the range-Doppler unit index value pairs corresponding to all peaks based on the range-Doppler spectrum data;

[0133] The channel data acquisition module is used to bring all the range-Doppler unit index value pairs into the transformation 4D matrix to obtain the corresponding two-dimensional matrices of multiple MIMO signal channel data;

[0134] The channel reconstruction module is used to construct a channel reconstruction matrix based on the virtual array characteristics; the two-dimensional matrix of MIMO signal channel data is filled into the channel reconstruction matrix in a specific order to obtain a non-sparse channel reconstruction matrix.

[0135] Preferably, the functions implemented by each functional module in this embodiment correspond one-to-one to the above method, and will not be described one by one here.

[0136] Example 4

[0137] Based on the same inventive concept, the present invention further provides a computer device, comprising a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other via the communication bus;

[0138] Memory for storing computer programs;

[0139] The processor, when used to execute the program stored in the memory, can implement a MIMO signal channel separation and reconstruction method for millimeter wave radar as described in Example 1 or 2.

[0140] The electronic device may include: a processor, a communications interface, a memory, and a communications bus, wherein the processor, the communications interface, and the memory communicate with each other via the communications bus. The processor may call logic instructions in the memory to execute a MIMO signal channel separation and reconstruction method for millimeter-wave radar in Example 1 or 2.

[0141] In addition, the logical instructions in the above-mentioned memory can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0142] Through the above technical solutions, it can be seen that compared with the existing technology, the present invention discloses a MIMO signal channel separation and reconstruction method and system for millimeter wave radar, which effectively realizes the MIMO signal channel separation in TDM mode, and considers the geometric structure of different radar antennas to solve the problem of MIMO signal channel separation and joint angular spectrum imaging based on two-dimensional array, with convenience and universality; the present invention makes full use of the acquired complex valued data, fully considers the geometric characteristics of the radar antenna array, improves the generalization ability of the MIMO signal channel separation program, and also enables it to better adapt and understand when processing diverse and complex radar data, thereby improving overall performance and robustness. The method proposed in the present invention can effectively separate MIMO multi-channel signals, improve the performance of millimeter wave radar, has high practical value, and provides a reference idea and practical path for the signal processing development of various millimeter wave radars.

[0143] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0144] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A MIMO signal channel separation and reconstruction method for millimeter wave radar, characterized in that: include: Obtain the echo signal of the millimeter-wave radar and convert it into multiple 4D matrices; Performing a fast Fourier transform based on the 4D matrix to obtain a transformed 4D matrix and range-Doppler spectrum data; Obtaining range-Doppler unit index value pairs corresponding to all peaks based on the range-Doppler spectrum data; Substituting all the range-Doppler unit index value pairs into the transformed 4D matrix, and correspondingly obtaining a plurality of MIMO signal channel data two-dimensional matrices; Constructing a channel reconstruction matrix based on the virtual array features; The MIMO signal channel data two-dimensional matrix is ​​filled into the channel reconstruction matrix in a specific order to obtain a non-sparse channel reconstruction matrix.

2. The MIMO signal channel separation and reconstruction method for millimeter wave radar according to claim 1, characterized in that: The echo signal acquisition method is: The transmitting antenna of the millimeter wave radar sequentially transmits electromagnetic wave signals according to channels; The electromagnetic wave signal is reflected back by the detector as a frequency sweep signal; The frequency sweep signal is received by the receiving antenna of the millimeter wave radar, and the echo signal is obtained after mixing and filtering.

3. The MIMO signal channel separation and reconstruction method for millimeter wave radar according to claim 1, characterized in that: The 4D matrix acquisition method is: Extracting a preset number of signed integer data based on the echo signal as original data; Based on the first half of the original data as real data; Based on the second half of the original data as imaginary data; generating complex data based on the combination of the real data and the imaginary data; The complex data are sorted and reorganized to obtain a plurality of 4D matrices.

4. The MIMO signal channel separation and reconstruction method for millimeter wave radar according to claim 3, characterized in that: The sorting and reorganization specifically includes: The complex data are sorted and reorganized according to the number of data frames, the number of frequency sweep signals between each frame, the number of frequency sampling points, the number of radar transmitting channels and the number of radar receiving channels.

5. The MIMO signal channel separation and reconstruction method for millimeter wave radar according to claim 2, characterized in that: The channel reconstruction matrix construction method is: Obtaining the number of transmitting antennas of the transmitting antenna in azimuth and elevation directions; Obtaining the number of receiving antennas of the receiving antenna in azimuth and elevation directions; Based on the number of transmitting antennas and the number of receiving antennas and according to the characteristics of the synthetic array of the partial virtual aperture of the radar antenna, a minimum rectangle including the virtual array surface is constructed as the channel reconstruction matrix.

6. The MIMO signal channel separation and reconstruction method for millimeter wave radar according to claim 5, characterized in that: Obtaining the non-sparse channel reconstruction matrix specifically includes: The two-dimensional matrix of MIMO signal channel data includes all virtual channel data; Based on each of the virtual channel data being filled into the corresponding geometric position in the channel reconstruction matrix in a specific order, the position without data filling is directly set to zero, thereby obtaining the non-sparse channel reconstruction matrix.

7. The MIMO signal channel separation and reconstruction method for millimeter wave radar according to claim 6, characterized in that: Filling the channel reconstruction matrix in a specific order is as follows: Numbering the transmitting antennas based on the transmission order of the transmitting antennas to obtain a transmission order number; Numbering the receiving antennas based on the receiving order of the receiving antennas to obtain a receiving order number; Based on the numbers of all virtual channel data in the two-dimensional matrix of the MIMO signal channel data, the channel reconstruction matrix is ​​filled according to the corresponding transmission sequence numbers and the reception sequence numbers.

8. The MIMO signal channel separation and reconstruction method for millimeter wave radar according to claim 7, characterized in that: The method for obtaining the virtual channel data number is: Based on the mth transmitting antenna in the millimeter wave radar transmitting a signal with preset parameters, multiple receiving antennas sequentially number the received signals according to the positions of the receiving antennas to obtain the virtual channel data number.

9. The MIMO signal channel separation and reconstruction method for millimeter wave radar according to claim 2, characterized in that: Also includes: Performing a two-dimensional fast Fourier transform based on the non-sparse channel reconstruction matrix to obtain two-dimensional angular spectrum data; Performing spectral imaging based on the amplitude of the two-dimensional angular spectrum data; The position of the detector in the vertical plane is obtained based on the spectral imaging result.

10. A MIMO signal channel separation and reconstruction system for millimeter wave radar, applied to a MIMO signal channel separation and reconstruction method for millimeter wave radar according to any one of claims 1 to 9, characterized in that: include: Signal acquisition module, signal processing module, index value pair acquisition module, channel data acquisition module and channel reconstruction module; The signal acquisition module is used to acquire the echo signal of the millimeter wave radar and convert it into multiple 4D matrices; The signal processing module is used to perform fast Fourier transform based on the 4D matrix to obtain a transformed 4D matrix and range-Doppler spectrum data; The index value pair acquisition module is used to obtain the range-Doppler unit index value pairs corresponding to all peaks based on the range-Doppler spectrum data; The channel data acquisition module is used to bring all the range-Doppler unit index value pairs into the transformation 4D matrix to obtain multiple MIMO signal channel data two-dimensional matrices; The channel reconstruction module is used to construct a channel reconstruction matrix based on the virtual array surface characteristics; The MIMO signal channel data two-dimensional matrix is ​​filled into the channel reconstruction matrix in a specific order to obtain a non-sparse channel reconstruction matrix.

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