MIMO radar signal processing method, device, radar and storage medium

Abstract

The present invention provides a signal processing method, device, radar, and storage medium for a MIMO radar. The method includes: before transmitting a signal, first modulating the multiple detection signals of the MIMO radar to different phases according to different transmission channels using the basic phase during phase modulation; then controlling each transmission channel to synchronously transmit its corresponding modulated detection signal, so that the detection signals transmitted by each transmission channel are beamformed in the outer space. Compared with TDM MIMO, the signal processing method provided in this application enables each transmission channel of the radar to participate in the transmission of all detection signals, thereby improving the intra-frame transmission gain and correspondingly extending the time for coherent processing of each receiving channel, thereby extending the radar's effective range and ensuring that the radar can still take into account the angular resolution performance within a longer effective range.

Description

Technical Field

[0001] The present invention relates to the field of radar technology, and in particular to a signal processing method and device for a MIMO radar, a radar, and a storage medium. Background Art

[0002] With the development of smart cars and autonomous driving technology, ADAS (Advanced Driver Assistance System) requirements for millimeter-wave radar sensors are becoming increasingly stringent. Furthermore, to ensure that targets in multiple lanes can be distinguished at long distances, millimeter-wave radars also need to have high angular resolution. MIMO (Multiple Input Multiple Output) solutions are commonly used to improve angular resolution. This involves using multiple transmit and receive channels to create a larger virtual aperture and form a narrower beam.

[0003] Conventional TDM (Time Division Multiplexing) MIMO radars use multiple transmit channels in a time-division fashion to improve angular resolution. This creates a virtual aperture that effectively enhances angular resolution. However, TDM MIMO's excessive number of virtual receive channels consumes excessive storage resources, shortening the effective integration time of each receive channel and resulting in a loss of coherent integration gain. Furthermore, additional virtual receive channels, while improving angular resolution, provide no incoherent integration gain, reducing the radar's range. Summary of the Invention

[0004] In view of this, the present invention provides a signal processing method, device, radar and storage medium for a MIMO radar, which can solve the problem in the prior art that TDM MIMO radar cannot ensure angular resolution performance while taking into account the effective range.

[0005] In a first aspect, an embodiment of the present invention provides a signal processing method for a MIMO radar, wherein the MIMO radar includes M transmission channels. The method includes:

[0006] by It is the basic phase during phase modulation. Different phases are modulated for multiple detection signals of MIMO radar according to different transmission channels.

[0007] Each transmitting channel is controlled to synchronously transmit its corresponding modulated detection signal, so that the detection signal transmitted by each transmitting channel is beamformed in the outer space.

[0008] In a second aspect, an embodiment of the present invention provides a signal processing device for a MIMO radar, including:

[0009] The MIMO radar includes M transmission channels; the device includes:

[0010] Phase modulation module for It is the basic phase during phase modulation. Different phases are modulated for multiple detection signals of MIMO radar according to different transmission channels.

[0011] The transmitting module is used to control each transmitting channel to synchronously transmit its corresponding modulated detection signal, so that the detection signal transmitted by each transmitting channel can be beamformed in the outer space.

[0012] In a third aspect, an embodiment of the present invention provides a radar, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the method described in any possible implementation of the first aspect are implemented.

[0013] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method described in any possible implementation of the first aspect above are implemented.

[0014] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0015] Before transmitting the signal, the embodiment of the present invention first The base phase for phase modulation is used to modulate the multiple detection signals of the MIMO radar to different phases according to the different transmit channels. Each transmit channel is then controlled to synchronously transmit its corresponding modulated detection signal, so that the detection signals transmitted by each transmit channel are beamformed in the outer space. Compared to TDM MIMO, the signal processing method provided in this embodiment enables each transmit channel of the radar to participate in the transmission of all detection signals, thereby improving the intra-frame transmission gain and correspondingly extending the time for coherent processing on each receive channel, thereby extending the radar's effective range and ensuring that the radar still maintains angular resolution performance at longer ranges. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, 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 only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1is a flow chart of an implementation method of a MIMO radar signal processing method according to an embodiment of the present invention;

[0018] Figure 2 Schematic diagram of phase modulation and timing of a detection signal provided by an embodiment of the present invention;

[0019] Figure 3 Schematic diagram of speed interval division of RD data provided by an embodiment of the present invention;

[0020] Figure 4 1 is a schematic structural diagram of a signal processing device for a MIMO radar provided by an embodiment of the present invention;

[0021] Figure 5 FIG. 4 is a schematic diagram of a radar provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0022] In the following description, specific details such as particular system structures and techniques are provided for purposes of illustration, not limitation, to facilitate a thorough understanding of the embodiments of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

[0023] In order to make the purpose, technical solutions and advantages of the present invention more clear, specific embodiments will be described below with reference to the accompanying drawings.

[0024] See also Figure 1 , which shows a flow chart of a signal processing method for a MIMO radar provided by an embodiment of the present invention, wherein the MIMO radar includes M transmission channels; the method is described in detail as follows:

[0025] S101: It is the basic phase during phase modulation. Different phases are modulated for the multiple detection signals of the MIMO radar according to the different transmission channels.

[0026] S102: Control each transmission channel to synchronously transmit its corresponding modulated detection signal, so that the detection signal transmitted by each transmission channel is beamformed in the outer space.

[0027] In a possible embodiment, the specific implementation process of S101 further includes:

[0028] According to the formula performing phase modulation on each detection signal;

[0029] in, It represents the phase of the detection signal corresponding to the i-th transmission timing of the j-th transmission channel, where j represents the transmission channel number and i represents the transmission timing.

[0030] To address the problem in the prior art that TDM MIMO radars cannot ensure both angular resolution performance and effective range, this embodiment discloses a signal processing method for a DDM (Doppler Division Multiplexing) MIMO radar that balances angular resolution performance and radar effective range.

[0031] Specifically, this embodiment transmits detection signals by simultaneously activating multiple transmission channels. Different transmission channels are modulated with different phases during each transmission sequence. The phase modulation formula is shown above, where i∈[0,N-1], N represents the total number of detection signals, M represents the total number of transmission channels, and j∈[1,M].

[0032] It should be noted that in order to effectively detect the target and extract the target information, as well as to achieve target speed defuzzification, The fundamental phase is critical, dividing 2π into M+1 equal parts, rather than M equal parts, the number of transmission channels. This design determines the subsequent target detection and information extraction methods, as well as the target velocity deambiguation method. It also solves the problem of overlapping targets of different ambiguity orders at the same distance.

[0033] For the convenience of description, here we take the three-transmit and four-receive millimeter-wave radar with three transmitting channels and four receiving channels as an example, that is, M=3, H=4, and the detection signal uses the chirp signal, such as Figure 2 In fact, the method provided in this embodiment is not limited to three-transmitter-four-receiver millimeter-wave radars, but is also applicable to multi-transmitter-multi-receiver array radars of other sizes.

[0034] Specifically, if Figure 2 As shown, for a three-transmitter, four-receiver millimeter-wave radar, according to the above phase modulation relationship, we can obtain:

[0035] Chirp modulation phase of the transmit channel Tx1:

[0036] Chirp modulation phase of the transmit channel Tx2:

[0037] Chirp modulation phase of transmit channel Tx3:

[0038] It can be seen that as the number of chirp transmissions increases, the above modulation phase will become larger and larger, and will exceed 2π. In fact, when the phase exceeds 2π, the actual modulation phase is the part that does not exceed 2π after subtracting the integer multiple of 2π. For example, according to the above modulation phase timing, the result is The actual modulation phase is

[0039] Assume that a three-transmit, four-receive DDM MIMO radar receives all N chirp signals within a frame and then performs FFT processing on the data of each receive channel in both the range and Doppler dimensions. This results in four two-dimensional complex matrices, labeled A, B, C, and D, corresponding to the four receive channels Rx1, Rx2, Rx3, and Rx4. Compared to TDM MIMO, when using the same total number of transmitted chirps, each transmit channel in a DDM MIMO radar participates in transmitting all chirp signals, resulting in a longer coherent processing time for each receive channel. In contrast, each transmit channel in a TDM MIMO radar participates in transmitting only a portion of the chirp signals, resulting in a shorter coherent processing time for each receive channel. For example, the coherent integration time of a three-transmit, four-receive DDM MIMO radar is three times that of TDM MIMO, resulting in higher processing gain.

[0040] Taking into account the average intra-frame transmit gain of DDM MIMO in the transmit beamforming stage and the processing gain of the two-dimensional coherent accumulation link in the echo signal processing stage, the three-transmit four-receive radar DDM MIMO can achieve an approximately 5dB gain improvement compared to TDM MIMO, corresponding to a 33% increase in radar range. The resulting effect is that without changing the antenna form, the effective range of the millimeter-wave radar can be increased from 150 meters to 200 meters by simply using the DDM MIMO waveform configuration and corresponding signal processing. Therefore, the signal processing method provided in this embodiment has obvious advantages for the application of long-range millimeter-wave radars and can make up for the defect that the effective range of TDM MIMO radars is difficult to increase.

[0041] In one possible embodiment, the MIMO radar includes H receiving channels. After the radar transmit signal is processed based on the method from S101 to S102, the corresponding echo signal processing process includes:

[0042] S201: Acquire target echo signals received by each of H receiving channels of the MIMO radar.

[0043] Specifically, the MIMO radar receives target echo signals through H receiving channels.

[0044] S202: Perform FFT processing in the Doppler dimension and the range dimension on the H target echo signals respectively to obtain H two-dimensional complex matrices corresponding one-to-one to the H receiving channels.

[0045] S203: Convert the H two-dimensional complex matrices into RD two-dimensional matrices; the RD two-dimensional matrix includes RD data; the RD data includes distance information and speed information.

[0046] In this embodiment, RD (range-doppler) data is two-dimensional data including range information (range) and velocity information (doppler), wherein the range information is the distance between the radar target and the radar, and the velocity information is the radial velocity between the radar and the radar target.

[0047] In a possible embodiment, the specific implementation process of S203 includes:

[0048] Calculate the modulus of each two-dimensional complex matrix to obtain H two-dimensional real matrices;

[0049] Perform non-coherent accumulation on each two-dimensional real matrix to obtain an RD two-dimensional matrix.

[0050] In this embodiment, the two-dimensional complex matrices corresponding to the H receiving channels are modulo each other to obtain the two-dimensional real matrices corresponding to the H receiving channels, and then non-coherent accumulation is performed on each two-dimensional real matrix to obtain an RD two-dimensional matrix.

[0051] S204: For each RD data, the radar target corresponding to the RD data is taken as the designated target, and the RD data of the designated target in the speed interval corresponding to each transmission channel is obtained from the RD two-dimensional matrix according to the translation relationship of multiple speed intervals in the Doppler dimension, and the speed information and distance information of the designated target are determined according to the RD data of the designated target in the speed interval corresponding to the initial transmission channel; the angle information of the designated target is obtained based on the RD data of the designated target in the speed interval corresponding to each transmission channel; the initial transmission channel is a transmission channel in which the modulation phase is 0 when the detection signal is phase modulated.

[0052] In one possible embodiment, the speed intervals in the Doppler dimension include M+1. The specific implementation process of step S204 of "obtaining RD data of the designated target in the speed interval corresponding to each transmission channel from the RD two-dimensional matrix according to the translation relationship of the multiple speed intervals in the Doppler dimension" includes:

[0053] The distance information of the first RD data is used as the target distance; the first RD data is any RD data;

[0054] According to the translation relationship of M+1 speed intervals in the Doppler dimension, searching for M RD data corresponding to the target distance in addition to the first RD data from the RD two-dimensional matrix;

[0055] Selecting the speed interval where the RD data with the smallest amplitude is located from the M+1 RD data corresponding to the target distance as the empty interval;

[0056] Based on the positional relationship between the empty interval and the speed interval of each transmission channel, RD data corresponding to the first designated target in the speed interval of each transmission channel is determined, where the first designated target is the radar target corresponding to the first RD data.

[0057] In this embodiment, the multiple transmission signals of DDM MIMO are modulated with different phases and transmitted simultaneously, which is equivalent to a single transmission signal being replicated and shifted multiple times in the frequency domain according to a certain frequency interval. The Doppler shift of two adjacent intervals is

[0058] Taking the three-transmit four-receive DDM MIMO radar as an example, the corresponding RD data of the three-transmit four-receive DDM MIMO radar after the above phase modulation shows the following characteristics: Figure 3 As shown in Figure 1. The radar target is repeated multiple times along the Doppler dimension at a certain interval on the RD data. In the form of , the corresponding RD data is equivalent to being divided into M+1 equal parts in the Doppler dimension, forming M+1 RD-divided velocity intervals. The actual number of transmitting channels is M. Then, only M velocity intervals have real RD data, which are valid intervals, while the other interval does not have real RD data, which is an empty interval.

[0059] Specifically, when dividing the velocity interval in the Doppler dimension, we first need to obtain the maximum unambiguity V max , then set -V max ~V max Divided into M+1 speed intervals. Due to the characteristics of DDM MIMO spectrum replication and migration, the target speed unambiguity is reduced, and the maximum unambiguous speed V max For non-MIMO Targets of different speed ranges are distributed in different intervals, so the empty intervals corresponding to targets of different speed ranges are distributed differently. The positional relationship between the empty intervals and the speed intervals of each transmit channel can be: the speed intervals are arranged in order of speed, and the empty interval is located in the speed interval above the speed interval corresponding to TX1.

[0060] For example, assuming that only a single transmission channel transmits the detection signal, the corresponding maximum unambiguous speed is V max, then for the three-transmitter, four-receiver radar configured according to the above DDM MIMO, the speed boundaries of the four equally divided intervals are V1~V2, V2~0, 0~V3, and V3~V4, where V1~V2 is speed interval ①, V2~0 is speed interval ②, 0~V3 is speed interval ③, and V3~V4 is speed interval ④; and V1=-V max 、 V4=V max .

[0061] Assuming that the target speed of a radar target transmitted through transmit channel Tx1 is within speed interval ①, the DDM MIMO RD data has a blank interval in ④, the target speed of transmit channel Tx2 is within speed interval ②, and the target speed of transmit channel Tx3 is within speed interval ③. Assuming that the target speed of a radar target transmitted through transmit channel Tx1 is within speed interval ②, the DDM MIMO RD data has a blank interval in ①, the target speed of transmit channel Tx2 is within speed interval ③, and the target speed of transmit channel Tx3 is within speed interval ④. Assuming that the target speed of a radar target transmitted through transmit channel Tx1 is within speed interval ③, the DDM MIMO RD data has a blank interval in ②, the target speed of transmit channel Tx2 is within speed interval ④, and the target speed of transmit channel Tx3 is within speed interval ①. Assuming that the target speed of a radar target transmitted through transmit channel Tx1 is within speed interval ④, the DDM MIMO RD data has a blank interval in ③, the target speed of transmit channel Tx2 is within speed interval ①, and the target speed of transmit channel Tx3 is within speed interval ②.

[0062] Based on the positional relationship of the speed intervals, after acquiring the RD data, this embodiment needs to first determine the speed interval in which the RD data is located, and then search the RD data corresponding to other speed intervals from the RD two-dimensional matrix according to the positional relationship of each speed interval.

[0063] For example, the coordinates of a RD data are (d x ,r y ) and is located in the speed range ①, that is, in the d x Doppler unit, rth y distance units, then according to the law of Doppler shift, pick out r from the RD two-dimensional matrix in turn y The other three RD data on the distance unit are located at And compare the amplitudes of the four RD data, find the interval where the RD data with the smallest amplitude is located as the empty interval. Assuming that the empty interval corresponding to the point with the smallest amplitude is in speed interval ③, then according to Figure 3The relationship between the above-mentioned empty interval and the speed intervals corresponding to Tx1, Tx2, and Tx3 can determine that the target corresponding to the transmission channel Tx1 is in speed interval ④. Since the modulation phase of the detection signal of the transmission channel Tx1 is 0, the speed information corresponding to the transmission channel is the true speed of the radar target. The speed of the radar target corresponding to the transmission channel Tx2 is in speed interval ①, and the speed of the radar target corresponding to the transmission channel Tx3 is in speed interval ②.

[0064] After determining the RD data in the speed range corresponding to each transmission channel, select the d in the RD data in the speed range corresponding to the transmission channel Tx1. x As the velocity information of the corresponding radar target, r y As the distance information of the radar target.

[0065] In one possible embodiment, the specific implementation process of step S204 of "obtaining the angle information of the designated target based on the RD data of the designated target in the speed range corresponding to each transmission channel" includes:

[0066] Converting the RD data of the first designated target in the speed range corresponding to each transmitting channel into H two-dimensional complex data respectively; obtaining an M×H virtual receiving channel data sequence corresponding to the first designated target; the first designated target is the radar target corresponding to any RD data;

[0067] Perform FFT processing on the M×H virtual receiving channel data sequences corresponding to the first designated target, and obtain angle information corresponding to the first designated target according to the position of the peak point in the FFT processing result, where the first designated target is any radar target.

[0068] In this embodiment, the specific process of converting the RD data of the designated target in the speed range corresponding to each transmission channel into H-channel two-dimensional complex data includes:

[0069] For each RD data of the specified target in the corresponding speed range of each transmission channel, the two-dimensional complex data corresponding to the RD data is searched from H two-dimensional complex matrices to obtain H two-dimensional complex data corresponding to the RD data; finally, an M×H virtual receiving channel data sequence is formed.

[0070] In this embodiment, it is assumed that the transmit and receive arrays of a three-transmit, four-receive radar are arranged in a uniform linear array, the twelve virtual receive channels formed by DDM MIMO are evenly arranged in space, and the distance between any two adjacent virtual receive antenna arrays is half a wavelength.

[0071] Assume that the coordinates of a radar target corresponding to the three transmission channels Tx1, Tx2, and Tx3 in the RD data are (d tx1 ,rtx1 )、(d tx2 ,r tx2 )、(d tx3 ,r tx3 ), the specific method for determining the data sequence of the twelve virtual receiving channels is as follows:

[0072] The coordinates of the radar target corresponding to the transmitting channel Tx1 in the RD data are (d tx1 ,r tx1 ), then search (d tx1 ,r tx1 ) corresponds to the two-dimensional complex data, and the first to fourth virtual receiving channel data are obtained as follows: A(d tx1 ,r tx1 )、B(d tx1 ,r tx1 )、C(d tx1 ,r tx1 )、D(d tx1 ,r tx1 );

[0073] The coordinates of the radar target corresponding to the transmitting channel Tx2 in the RD data are (d tx2 ,r tx2 ), then search (d tx2 ,r tx2 ) corresponds to the two-dimensional complex data, and the fifth to eighth virtual receiving channel data are obtained as follows: A(d tx2 ,r tx2 )、B(d tx2 ,r tx2 )、C(d tx2 ,r tx2 )、D(d tx2 ,r tx2 );

[0074] The coordinates of the radar target corresponding to the transmitting channel Tx3 in the RD data are (d tx3 ,r tx3 ), then search (d tx3 ,r tx3 ) corresponds to the two-dimensional complex data, and the ninth to twelfth virtual receiving channel data are obtained as follows: A(d tx3 ,r tx3 )、B(d tx3 ,r tx3 )、C(d tx3 ,r tx3 )、D(d tx3 ,r tx3 );

[0075] So the complete twelve virtual receiving channel data sequence is:

[0076] [A(d tx1 ,r tx1 )、B(d tx1 ,r tx1 )、C(d tx1 ,r tx1 )、D(d tx1 ,r tx1 )、A(d tx2 ,r tx2 )、B(d tx2 ,r tx2 )、C(d tx2 ,r tx2 )、D(d tx2 ,r tx2 )、A(d tx3 ,r tx3 )、B(d tx3 ,r tx3 )、C(d tx3 ,r tx3 )、D(d tx3 ,r tx3 )], and then perform K-point FFT calculation on the sequence. K can be an integer power of 2, and K ≥ 256. The larger K is, the higher the angle calculation accuracy is. The angle information of the initial target point can be obtained by searching the position L of the peak point in the K-point FFT result. The calculation formula can be:

[0077] After this step, the basic information of the radar target, such as speed, distance, and angle, are extracted. Then, complex data processing algorithms such as clustering, clutter removal, target tracking, target recognition, and alarm signal generation are used to realize the basic functions of the vehicle-mounted millimeter-wave radar.

[0078] In a possible embodiment, before S203, the method provided in this embodiment further includes:

[0079] All RD data in the RD two-dimensional matrix are subjected to constant false alarm detection, and RD data with amplitudes smaller than a preset threshold are eliminated.

[0080] In this embodiment, a batch of false radar target data can be screened out in advance through constant false alarm detection, thereby improving the accuracy of radar data processing.

[0081] From the above embodiments, it can be seen that before transmitting a signal, the embodiment of the present invention first The basic phase during phase modulation is used, and different phases are modulated for the multiple detection signals of the MIMO radar according to the different transmission channels; then, each transmission channel is controlled to synchronously transmit its corresponding modulated detection signal, so that the detection signals transmitted by each transmission channel are beamformed in the outer space. The signal processing method provided in this embodiment can be effectively applied to long-range radars. It has a greater transmission gain and a greater coherent accumulation gain than traditional TDM MIMO radars, which are very beneficial for detecting weak targets at long distances. At the same time, the use of relevant radar waveform design and signal processing methods can effectively solve the problem of velocity ambiguity. The target finally output has the angular resolution performance of TDM MIMO, and the effective range is farther than TDM MIMO. The velocity deambiguation method is more concise and efficient.

[0082] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0083] The following are device embodiments of the present invention. For details not fully described therein, reference may be made to the corresponding method embodiments described above.

[0084] Figure 4 A schematic diagram of the structure of a signal processing device 100 for a MIMO radar according to an embodiment of the present invention is shown. For ease of explanation, only the parts related to the embodiment of the present invention are shown, which are described in detail as follows:

[0085] like Figure 4 As shown, the signal processing device 100 of the MIMO radar includes:

[0086] Phase modulation module 110, used to It is the basic phase during phase modulation. Different phases are modulated for multiple detection signals of MIMO radar according to different transmission channels.

[0087] The transmitting module 120 is used to control each transmitting channel to synchronously transmit its corresponding modulated detection signal, so that the detection signal transmitted by each transmitting channel is beamformed in the outer space.

[0088] In one possible embodiment, the phase modulation module 110 includes:

[0089] According to the formula performing phase modulation on each detection signal;

[0090] in, It represents the phase of the detection signal corresponding to the i-th transmission timing of the j-th transmission channel, where j represents the transmission channel number and i represents the transmission timing.

[0091] In a possible embodiment, the signal processing device 100 of the MIMO radar further includes:

[0092] An echo signal acquisition module is used to acquire target echo signals received by each of the H receiving channels of the MIMO radar;

[0093] The complex matrix acquisition module is used to perform FFT processing in the Doppler dimension and the range dimension on the H target echo signals respectively, and obtain H two-dimensional complex matrices corresponding to the H receiving channels;

[0094] An RD data acquisition module, configured to convert H two-dimensional complex matrices into RD two-dimensional matrices; the RD two-dimensional matrix includes RD data; the RD data includes distance information and speed information;

[0095] a target information acquisition module, configured to, for each RD data, identify the radar target corresponding to the RD data as a designated target, obtain the RD data of the designated target in the speed interval corresponding to each transmission channel from the RD two-dimensional matrix based on the translation relationship between multiple speed intervals in the Doppler dimension, determine the speed information and distance information of the designated target based on the RD data of the designated target in the speed interval corresponding to the initial transmission channel, and obtain the angle information of the designated target based on the RD data of the designated target in the speed interval corresponding to each transmission channel;

[0096] The initial transmission channel is a transmission channel in which the modulation phase of the detection signal is 0 during phase modulation.

[0097] In a possible embodiment, the RD data acquisition module specifically includes:

[0098] Calculate the modulus of each two-dimensional complex matrix to obtain H two-dimensional real matrices;

[0099] Perform non-coherent accumulation on each two-dimensional real matrix to obtain an RD two-dimensional matrix.

[0100] In a possible embodiment, the speed intervals in the Doppler dimension include M+1; and the target information acquisition module includes:

[0101] The distance information of the first RD data is used as the target distance; the first RD data is any RD data;

[0102] According to the translation relationship of M+1 speed intervals in the Doppler dimension, searching for M RD data corresponding to the target distance in addition to the first RD data from the RD two-dimensional matrix;

[0103] Selecting the speed interval where the RD data with the smallest amplitude is located from the M+1 RD data corresponding to the target distance as the empty interval;

[0104] Based on the positional relationship between the empty interval and the speed interval of each transmission channel, RD data corresponding to the first designated target in the speed interval of each transmission channel is determined, where the first designated target is the radar target corresponding to the first RD data.

[0105] In a possible embodiment, the MIMO radar includes H receiving channels; the target information acquisition module further includes:

[0106] Converting the RD data of the designated target in the speed range corresponding to each transmission channel into H two-dimensional complex data respectively; obtaining an M×H virtual receiving channel data sequence corresponding to the first designated target; the first designated target is any radar target;

[0107] Perform FFT processing on the M×H virtual receiving channel data sequence corresponding to the first designated target, and obtain angle information corresponding to the first designated target according to the position of the peak point in the FFT processing result, where the first designated target is the radar target corresponding to the first RD data.

[0108] In a possible embodiment, the signal processing device 100 of the MIMO radar further includes:

[0109] The constant false alarm detection module is used to perform constant false alarm detection on all RD data in the RD two-dimensional matrix and eliminate RD data with amplitudes less than a preset threshold.

[0110] From the above embodiments, it can be seen that before transmitting a signal, the embodiment of the present invention first The base phase for phase modulation is used to modulate the multiple detection signals of the MIMO radar to different phases according to the different transmit channels. Each transmit channel is then controlled to synchronously transmit its corresponding modulated detection signal, so that the detection signals transmitted by each transmit channel are beamformed in the outer space. Compared to TDM MIMO, the signal processing method provided in this embodiment enables each transmit channel of the radar to participate in the transmission of all detection signals, thereby improving the intra-frame transmission gain and correspondingly extending the time for coherent processing on each receive channel, thereby extending the radar's effective range and ensuring that the radar still maintains angular resolution performance at longer ranges.

[0111] Figure 5 FIG. 1 is a schematic diagram of a radar provided by an embodiment of the present invention. Figure 5 As shown, the radar 5 of this embodiment includes: a processor 50, a memory 51, and a computer program 52 stored in the memory 51 and executable on the processor 50. When the processor 50 executes the computer program 52, the steps in the above-mentioned signal processing method embodiments of the MIMO radar are implemented, such as Figure 1Alternatively, when the processor 50 executes the computer program 52, the functions of the modules / units in the above-mentioned device embodiments are realized, for example, Figure 4 The functions of the modules 110 to 120 are shown.

[0112] Exemplarily, the computer program 52 may be divided into one or more modules / units, which are stored in the memory 51 and executed by the processor 50 to implement the present invention. The one or more modules / units may be a series of computer program instruction segments capable of implementing specific functions, and the instruction segments are used to describe the execution process of the computer program 52 in the radar 5.

[0113] The radar 5 may include, but is not limited to, a processor 50 and a memory 51. Those skilled in the art will understand that Figure 5 This is merely an example of the radar 5 and does not constitute a limitation of the radar 5 . The radar 5 may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the radar may also include input and output devices, network access devices, buses, etc.

[0114] The processor 50 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0115] The memory 51 can be an internal storage unit of the radar 5, such as the radar 5's hard drive or memory. It can also be an external storage device of the radar 5, such as a plug-in hard drive, a Smart Media Card (SMC), a Secure Digital (SD) card, a Flash Card, etc. Furthermore, the memory 51 can include both the radar 5's internal storage unit and an external storage device. The memory 51 is used to store the computer program and other programs and data required by the radar. The memory 51 can also be used to temporarily store data that has been output or is about to be output.

[0116] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0117] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0118] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present invention.

[0119] In the embodiments provided herein, it should be understood that the disclosed devices / radars and methods can be implemented in other ways. For example, the device / radar embodiments described above are merely illustrative. For example, the division of modules or units is merely a logical functional division. In actual implementation, other divisions may be employed, such as combining or integrating multiple units or components into another system, or omitting or disabling certain features. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through interfaces, or indirect coupling or communication connection between devices or units may be electrical, mechanical, or otherwise.

[0120] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0121] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0122] If the integrated module / unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention can also implement all or part of the processes in the above-mentioned method embodiments by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When executed by a processor, the computer program can implement the steps of the above-mentioned MIMO radar signal processing method embodiments. The computer program includes computer program code, which can be in source code form, object code form, executable file, or some intermediate form. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard drive, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practices in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practices, computer-readable media does not include electrical carrier signals and telecommunication signals.

[0123] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the scope of protection of the present invention.

Claims

1. A signal processing method for a MIMO radar, characterized in that: The MIMO radar includes M transmission channels; the method includes: by It is the basic phase during phase modulation. Different phases are modulated for multiple detection signals of MIMO radar according to different transmission channels. Controlling each transmitting channel to synchronously transmit its corresponding modulated detection signal so that the detection signals transmitted by each transmitting channel are beamformed in the outer space; The MIMO radar includes H receiving channels, and the method further includes: Obtaining target echo signals received by each of H receiving channels of the MIMO radar; Perform FFT processing on the H target echo signals in the Doppler dimension and the range dimension respectively, and obtain H two-dimensional complex matrices corresponding to the H receiving channels. Converting H two-dimensional complex matrices into RD two-dimensional matrices; the RD two-dimensional matrix includes RD data; the RD data includes distance information and speed information; For each RD data, the radar target corresponding to the RD data is taken as the designated target, the RD data of the designated target in the speed interval corresponding to each transmission channel is obtained from the RD two-dimensional matrix based on the translation relationship of multiple speed intervals in the Doppler dimension, and the speed information and distance information of the designated target are determined based on the RD data of the designated target in the speed interval corresponding to the initial transmission channel; and the angle information of the designated target is obtained based on the RD data of the designated target in the speed interval corresponding to each transmission channel. The initial transmission channel is a transmission channel in which the modulation phase of the detection signal is 0 during phase modulation; The speed intervals in the Doppler dimension include M+1; and obtaining RD data of the designated target in the speed interval corresponding to each transmission channel from the RD two-dimensional matrix according to the translation relationship of the multiple speed intervals in the Doppler dimension includes: The distance information of the first RD data is used as the target distance; the first RD data is any RD data; According to the translation relationship of M+1 speed intervals in the Doppler dimension, searching for M RD data corresponding to the target distance in addition to the first RD data from the RD two-dimensional matrix; Selecting the speed interval where the RD data with the smallest amplitude is located from the M+1 RD data corresponding to the target distance as the empty interval; Determining, based on a positional relationship between the empty interval and the speed intervals of the respective transmission channels, RD data corresponding to a first designated target in the speed intervals of the respective transmission channels, where the first designated target is a radar target corresponding to the first RD data; The obtaining the angle information of the designated target based on the RD data of the designated target in the speed interval corresponding to each transmission channel includes: Converting the RD data of the first designated target in the speed range corresponding to each transmitting channel into H two-dimensional complex data respectively; obtaining an M×H virtual receiving channel data sequence corresponding to the first designated target; the first designated target is any radar target; Perform FFT processing on the M×H virtual receiving channel data sequence corresponding to the first designated target, and obtain angle information corresponding to the first designated target according to the position of the peak point in the FFT processing result, where the first designated target is the radar target corresponding to the first RD data.

2. The signal processing method of the MIMO radar according to claim 1, wherein: Said This is the basic phase during phase modulation. Different phases are modulated for multiple detection signals of the MIMO radar according to different transmission channels, including: According to the formula performing phase modulation on each detection signal; in, It represents the phase of the detection signal corresponding to the i-th transmission timing of the j-th transmission channel, j represents the transmission channel number, i represents the transmission timing, i∈[0,N-1], N represents the total number of detection signals, j∈[1,M], M represents the total number of transmission channels.

3. The signal processing method of the MIMO radar according to claim 1, wherein: The converting of the H two-dimensional complex matrices into RD two-dimensional matrices includes: Calculate the modulus of each two-dimensional complex matrix to obtain H two-dimensional real matrices; Perform non-coherent accumulation on each two-dimensional real matrix to obtain an RD two-dimensional matrix.

4. The signal processing method of the MIMO radar according to claim 1, wherein: Before acquiring the RD data of the designated target in the speed interval corresponding to each transmission channel from the RD two-dimensional matrix according to the translation relationship of multiple speed intervals in the Doppler dimension, the method further includes: All RD data in the RD two-dimensional matrix are subjected to constant false alarm detection, and RD data with amplitudes smaller than a preset threshold are eliminated.

5. A signal processing device for a MIMO radar, characterized in that: The MIMO radar includes M transmission channels; the device includes: Phase modulation module for It is the basic phase during phase modulation. Different phases are modulated for multiple detection signals of MIMO radar according to different transmission channels. The transmitting module is used to control each transmitting channel to synchronously transmit its corresponding modulated detection signal, so that the detection signals transmitted by each transmitting channel are beamformed in the outer space; The MIMO radar includes H receiving channels, and the signal processing device of the MIMO radar also includes: An echo signal acquisition module is used to acquire target echo signals received by each of the H receiving channels of the MIMO radar; The complex matrix acquisition module is used to perform FFT processing in the Doppler dimension and the range dimension on the H target echo signals respectively, and obtain H two-dimensional complex matrices corresponding to the H receiving channels; An RD data acquisition module, configured to convert H two-dimensional complex matrices into RD two-dimensional matrices; the RD two-dimensional matrix includes RD data; the RD data includes distance information and speed information; a target information acquisition module, configured to, for each RD data, identify the radar target corresponding to the RD data as a designated target, obtain the RD data of the designated target in the speed interval corresponding to each transmission channel from the RD two-dimensional matrix based on the translation relationship between multiple speed intervals in the Doppler dimension, determine the speed information and distance information of the designated target based on the RD data of the designated target in the speed interval corresponding to the initial transmission channel, and obtain the angle information of the designated target based on the RD data of the designated target in the speed interval corresponding to each transmission channel; The initial transmission channel is a transmission channel in which the modulation phase of the detection signal is 0 during phase modulation; The speed intervals in the Doppler dimension include M+1; the target information acquisition module includes: The distance information of the first RD data is used as the target distance; the first RD data is any RD data; According to the translation relationship of M+1 speed intervals in the Doppler dimension, searching for M RD data corresponding to the target distance in addition to the first RD data from the RD two-dimensional matrix; Selecting the speed interval where the RD data with the smallest amplitude is located from the M+1 RD data corresponding to the target distance as the empty interval; Determining, based on a positional relationship between the empty interval and the speed intervals of the respective transmission channels, RD data corresponding to a first designated target in the speed intervals of the respective transmission channels, where the first designated target is a radar target corresponding to the first RD data; The target information acquisition module includes: Converting the RD data of the first designated target in the speed range corresponding to each transmitting channel into H two-dimensional complex data respectively; obtaining an M×H virtual receiving channel data sequence corresponding to the first designated target; the first designated target is any radar target; Perform FFT processing on the M×H virtual receiving channel data sequence corresponding to the first designated target, and obtain angle information corresponding to the first designated target according to the position of the peak point in the FFT processing result, where the first designated target is the radar target corresponding to the first RD data.

6. A radar, characterized in that: The method comprises a processor and a memory, wherein the memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory to execute the method according to any one of claims 1 to 4.

7. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 4 are implemented.

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