MIMO millimeter wave radar and signal processing method thereof

Abstract

This application provides a signal processing method for MIMO millimeter-wave radar. The MIMO millimeter-wave radar includes m transmitting antennas and x receiving antennas, wherein the m transmitting antennas and x receiving antennas are non-uniformly distributed, and m and x are both positive integers. The signal processing method for MIMO millimeter-wave radar includes: randomly controlling the m transmitting antennas to transmit detection signals; calculating the echo signals formed by the reflection of the detection signals from the target object through n virtual receiving channels, wherein the x receiving antennas and m transmitting antennas form n virtual receiving channels, and n is equal to the product of m and x; mixing the reference signal and the echo signal to obtain a processed signal; performing tensor completion on the processed signal to obtain a completed signal; and calculating the target distance, target velocity, and target angle of the target object based on the completed signal. Furthermore, this application also provides a main control device and a MIMO millimeter-wave radar. The signal processing method provided in this application can effectively improve the angular resolution of millimeter-wave radar.

Description

Technical Field

[0001] This application relates to the field of millimeter-wave radar technology, and in particular to a MIMO millimeter-wave radar and its signal processing method and main control device. Background Technology

[0002] In millimeter-wave radar systems used for indoor human observation, improving angular resolution is a key concern. Angular resolution directly affects target resolution and point cloud density. In practical applications, it is typically required to achieve the highest possible angular resolution within limited hardware resources. However, angular resolution is theoretically determined by the length of the physical aperture; increasing angular resolution means increasing the number of apertures, but using only the actual aperture to improve angular resolution is impractical for real-world applications. Summary of the Invention

[0003] In view of this, it is necessary to provide a MIMO millimeter-wave radar, its signal processing method, and main control equipment, which can effectively improve the angular resolution of millimeter-wave radar.

[0004] In a first aspect, embodiments of this application provide a signal processing method for a MIMO millimeter-wave radar. The MIMO millimeter-wave radar includes m transmitting antennas and x receiving antennas, wherein the m transmitting antennas and x receiving antennas are non-uniformly distributed, and m and x are both positive integers. The signal processing method for the MIMO millimeter-wave radar includes:

[0005] Randomly control the m transmitting antennas to transmit detection signals;

[0006] Calculate the echo signal formed by the reflection of the detection signal by the target object and receive it through n virtual receiving channels, wherein the x receiving antennas and the m transmitting antennas form the n virtual receiving channels, and n is equal to the product of m and x;

[0007] The reference signal and the echo signal are mixed to obtain the processed signal;

[0008] The processed signal is tensor-completed to obtain a completed signal; and

[0009] The target distance, target speed, and target angle of the target object are calculated based on the completion signal.

[0010] Secondly, embodiments of this application provide a master control device, the master control device comprising:

[0011] Memory, used to store program instructions; and

[0012] A processor is used to execute the program instructions to implement the signal processing method for MIMO millimeter-wave radar as described above.

[0013] Thirdly, embodiments of this application provide a MIMO millimeter-wave radar, the MIMO millimeter-wave radar comprising:

[0014] There are m transmitting antennas, wherein the m transmitting antennas are not uniformly distributed, and m is a positive integer;

[0015] There are x receiving antennas, wherein the x receiving antennas are not uniformly distributed, and x is a positive integer; and

[0016] The main control device described above is electrically connected to both the transmitting antenna and the receiving antenna.

[0017] The aforementioned MIMO millimeter-wave radar, its signal processing method, and main control equipment, based on an indoor millimeter-wave radar imaging method using randomly transmitted sparse array MIMO, achieves this by arranging the transmitting and receiving antennas in a non-uniform linear array and randomly controlling the transmitting antenna to transmit detection signals. This random time-division multiplexing of the transmitting antennas creates a three-dimensional receiving matrix consisting of a virtual receiving channel, a detection signal sequence, and a range-wavenumber. Tensor completion technology is used to fill in the gaps in the three-dimensional receiving matrix, enabling ranging, velocity, and angle measurement on the filled matrix, thus significantly improving angular resolution. MIMO millimeter-wave radar is advantageous for non-uniform linear array layouts, and the random time-division multiplexing MIMO technology can utilize virtual apertures to improve angular resolution, exhibiting excellent performance. This helps to maximize the performance potential of MIMO millimeter-wave radar systems without increasing the number of antenna channels. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0019] Figure 1 A flowchart illustrating the signal processing method for MIMO millimeter-wave radar provided in this application embodiment.

[0020] Figure 2 This is a first sub-flowchart of the signal processing method for MIMO millimeter-wave radar provided in an embodiment of this application.

[0021] Figure 3 This is a second sub-flowchart of the signal processing method for MIMO millimeter-wave radar provided in an embodiment of this application.

[0022] Figure 4The third sub-flowchart of the signal processing method for MIMO millimeter-wave radar provided in the embodiments of this application.

[0023] Figure 5 The fourth sub-flowchart of the signal processing method for MIMO millimeter-wave radar provided in the embodiments of this application.

[0024] Figure 6 The fifth sub-flowchart of the signal processing method for MIMO millimeter-wave radar provided in the embodiments of this application.

[0025] Figure 7 The sixth sub-flowchart of the signal processing method for MIMO millimeter-wave radar provided in the embodiments of this application.

[0026] Figure 8 The seventh sub-flowchart of the signal processing method for MIMO millimeter-wave radar provided in the embodiments of this application.

[0027] Figure 9 This is a schematic diagram of the internal structure of a MIMO millimeter-wave radar provided in an embodiment of this application.

[0028] Figure 10 A schematic diagram of the signal sequence of a conventional MIMO millimeter-wave radar provided in an embodiment of this application.

[0029] Figure 11 for Figure 1 The diagram shows the signal sequence of a MIMO millimeter-wave radar.

[0030] Figure 12 for Figure 1 The diagram shows a three-dimensional matrix of the processed signals from a MIMO millimeter-wave radar.

[0031] Figure 13 for Figure 1 The diagram shows a three-dimensional matrix of the completed signal from a MIMO millimeter-wave radar.

[0032] Figure 14 for Figure 2 The diagram shows the channel coordinate axes of a MIMO millimeter-wave radar.

[0033] Figure 15 This is a schematic diagram of a simulation scenario provided in an embodiment of this application.

[0034] Figure 16 for Figure 15 The diagram shows the internal structure of a MIMO millimeter-wave radar.

[0035] Figure 17 for Figure 15 The image shown is an image of the MIMO millimeter-wave radar.

[0036] Figure 18 for Figure 15 The image shown is an imaging result from a conventional MIMO millimeter-wave radar.

[0037] Figure 19 for Figure 15 The diagram shows the angular response results of the MIMO millimeter-wave radar.

[0038] Figure 20 for Figure 15 The diagram shows the angular direction response results of a conventional MIMO millimeter-wave radar.

[0039] Figure 21 This is a schematic diagram of the internal structure of the main control device provided in an embodiment of this application.

[0040] Figure 22 This is a schematic diagram of the internal structure of a MIMO millimeter-wave radar provided in an embodiment of this application.

[0041] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0043] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar planned objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data are interchangeable where appropriate; in other words, the described embodiments are implemented according to a sequence other than that illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, may also include other content; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0044] It should be noted that the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" and "second" may explicitly or implicitly include one or more of that feature. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0045] Please refer to Figure 10 This is a schematic diagram of the signal sequence of a conventional MIMO millimeter-wave radar provided in an embodiment of this application. Taking a conventional MIMO millimeter-wave radar with three transmitters and four receivers as an example, the conventional MIMO millimeter-wave radar with three transmitters and four receivers includes three transmitter antennas and four receiver antennas, which can form 12 virtual receiving channels. Among them, the three transmitter antennas and four receiver antennas are evenly distributed. Correspondingly, the 12 virtual receiving channels are evenly arranged.

[0046] Conventional MIMO millimeter-wave radar controls three transmitting antennas to sequentially transmit detection signals, causing the three transmitting antennas to periodically and cyclically transmit detection signals. For example... Figure 10 As shown, there are three transmitting antennas, T1, T2, and T3, and the detection signals transmitted by these three antennas are illustrated in the example. Transmitting antennas T1, T2, and T3 are controlled sequentially to transmit detection signals, and four receiving antennas sequentially receive the echo signals reflected back from the object. Correspondingly, the reception relationship between the 12 virtual receiving channels and the detection signals from the three transmitting antennas is shown in the example. Figure 10 As shown.

[0047] Please refer to the following: Figure 1 and Figure 9 , Figure 1 This is a flowchart illustrating the signal processing method for MIMO millimeter-wave radar provided in an embodiment of this application. Figure 9This is a schematic diagram of the internal structure of a MIMO millimeter-wave radar provided in an embodiment of this application. The MIMO (multiple input multiple output) millimeter-wave radar includes m transmitting antennas and x receiving antennas, with the x receiving antennas and m transmitting antennas forming n virtual receiving channels. Here, m and x are both positive integers, and n is equal to the product of m and x. The m transmitting antennas and x receiving antennas are non-uniformly distributed. Specifically, both the transmitting and receiving antennas are arranged in a non-uniform linear array (NULA) configuration, meaning that the spacing between two adjacent transmitting antennas and the spacing between two adjacent receiving antennas are not uniform half-wavelengths, but rather random and non-uniform. In this embodiment, the distribution of the transmitting and receiving antennas can be randomly formed or determined according to actual conditions, and is not limited here. Correspondingly, the virtual receiving channels are also non-uniformly distributed.

[0048] by Figure 9 Taking the MIMO millimeter-wave radar 30 shown as an example, the MIMO millimeter-wave radar 30 includes three transmitting antennas 31 and four receiving antennas 32. The three transmitting antennas 31 are T1, T2, and T3. The spacing between two adjacent transmitting antennas 31 is different, and the spacing between two adjacent receiving antennas 32 is also different.

[0049] The signal processing method for MIMO millimeter-wave radar specifically includes the following steps.

[0050] Step S102: Randomly control m transmitting antennas to transmit detection signals. It is understood that the transmission order of the m transmitting antennas is not limited but is randomly generated. The same transmitting antenna can continuously transmit detection signals, while different transmitting antennas can transmit detection signals a different number of times.

[0051] Step S104: Calculate the echo signal formed by the reflection of the detection signal received by the n virtual receiving channels by the target object.

[0052] by Figure 9 Taking the MIMO millimeter-wave radar 30 shown as an example, three transmitting antennas 31 and four receiving antennas 32 form 12 virtual receiving channels. These 12 virtual receiving channels are represented by the numbers 0-11. The three transmitting antennas 31 are controlled to randomly transmit detection signals, for example, in the order T1, T3, T2, T3, T2, T3, T1, T1, T3. The reception relationship between the 12 virtual receiving channels and the detection signals from the three transmitting antennas 31 is as follows: Figure 11 As shown.

[0053] The specific process of calculating the echo signal formed by the reflection of the detection signal received by n virtual receiving channels by the target object will be described in detail below.

[0054] Step S106: The reference signal and the echo signal are mixed to obtain the processed signal. To reduce sampling requirements, frequency demodulation techniques are used to mix the reference signal and the echo signal.

[0055] The specific process of mixing the reference signal and the echo signal to obtain the processed signal will be described in detail below.

[0056] Step S108: Perform tensor completion on the processed signal to obtain the completed signal. In this embodiment, converting the processed signal into a three-dimensional tensor form yields a corresponding three-dimensional matrix diagram (such as...). Figure 12 (As shown). The three coordinate axes of the 3D matrix represent the virtual receiving channel direction, the detection signal sequence direction, and the range-wavenumber direction, respectively. Blank areas represent no signal. Tensor completion of the processed signal involves filling in the blank areas in the 3D matrix representing the processed signal. The 3D matrix corresponding to the completed signal is shown below. Figure 13 As shown, the signal obtained by filling in the blank areas is the restored signal.

[0057] The specific process of performing tensor completion on the processed signal to obtain the completed signal will be described in detail below.

[0058] Step S110: Calculate the target distance, target speed, and target angle of the target object based on the completion signal.

[0059] The specific process of calculating the target distance, target velocity, and target angle of the target object based on the completed signal will be described in detail below.

[0060] In the above embodiments, the indoor millimeter-wave radar imaging method based on randomly transmitted sparse array MIMO, by setting the transmitting and receiving antennas to a non-uniform linear array arrangement and randomly controlling the transmitting antenna to transmit detection signals, enables the transmitting antenna to transmit in a random time-division multiplexing manner, thereby forming a three-dimensional receiving matrix of virtual receiving channels, detection signal sequence, and range wavenumber. Tensor completion technology is used to fill in the blank signals in the three-dimensional receiving matrix, and ranging, velocity, and angle measurement are performed on the filled three-dimensional receiving matrix, thus greatly improving angular resolution. MIMO millimeter-wave radar is advantageous for non-uniform linear array layouts, and the random time-division multiplexing MIMO technology can improve angular resolution using virtual apertures, exhibiting good performance and helping to maximize the performance potential of MIMO millimeter-wave radar systems without increasing the number of antenna channels.

[0061] Please refer to the following: Figure 2 and Figure 14 , Figure 2 This is a first sub-flowchart of the signal processing method for MIMO millimeter-wave radar provided in the embodiments of this application. Figure 14This is a schematic diagram of the channel coordinate axes of a MIMO millimeter-wave radar provided in an embodiment of this application. Before executing step S102, the signal processing method for the MIMO millimeter-wave radar further includes the following steps.

[0062] Step S202: Construct the channel coordinate axis. The first virtual receiving channel out of the n virtual receiving channels is located at the origin of the channel coordinate axis. The coordinates of the first virtual receiving channel on the channel coordinate axis are... .

[0063] Step S204: Obtain the first interval as the interval between the m transmitting antennas. Based on the arrangement of the m transmitting antennas, obtain the interval between each pair of transmitting antennas.

[0064] Step S206: Obtain the interval between the x receiving antennas as the second interval. Based on the arrangement of the x receiving antennas, obtain the interval between each pair of receiving antennas.

[0065] Step S208: Calculate the coordinates of the remaining virtual receiving channels among the n virtual receiving channels on the channel coordinate axis based on the first and second intervals. Calculate the coordinates of the remaining virtual receiving channels (excluding the first virtual receiving channel) based on the arrangement of the transmitting and receiving antennas. The coordinates of the virtual receiving channels are as follows: .

[0066] Please refer to the following: Figure 3 This is the second sub-flowchart of the signal processing method for MIMO millimeter-wave radar provided in the embodiments of this application. Step S104 specifically includes the following steps.

[0067] Step S302: Calculate the virtual distance between the target object and the virtual receiving channel. In this embodiment, assume the target object is P, that the echo reflected by the target object P is in the form of a plane wave, and that the target scattering coefficient is a unit value. Based on the above assumptions, calculate the distance between the target object P and the virtual receiving channel, i.e., the virtual distance. .

[0068] The specific process of calculating the virtual distance between the target object and the virtual receiving channel will be described in detail below.

[0069] Step S304: Calculate the detection delay of the detection signal based on the virtual distance. In this embodiment, the detection delay is calculated according to the first formula. Specifically, the first formula is: .in, Indicates detection delay. It represents the speed of light.

[0070] Step S306: Calculate the echo signal based on the detection signal and the detection delay. In this embodiment, the detection signal is represented as: .in, Indicates the detection signal, Indicates the imaginary part. Indicates a fast time. This represents the window function used to detect the chirp signal in the signal. Indicates the carrier frequency. This represents the chirp rate of the detected signal.

[0071] Accordingly, the echo signal is represented as: .in, Indicates the echo signal. A window function representing the direction of the virtual receive channel. This represents the window function used to detect the signal sequence. It can be understood that the echo signal has three dimensions: the distance direction, the direction of the virtual receiving channel, and the direction of the detected signal sequence.

[0072] Please refer to the following: Figure 4 This is the third sub-flowchart of the signal processing method for MIMO millimeter-wave radar provided in the embodiments of this application. Step S302 specifically includes the following steps.

[0073] Step S402: Obtain the distance between the target object and the first virtual receiving channel in the channel coordinate axis as the origin distance. In this embodiment, the origin distance can be obtained based on the coordinates of the target object P on the channel coordinate axis. .

[0074] Step S404: Calculate the first value based on the coordinates of the virtual receiving channel on the channel coordinate axis and the incident angle of the echo signal on the channel coordinate axis. In this embodiment, the first value is expressed as: .in, This indicates the angle of incidence of the echo.

[0075] Step S406: Calculate the second value based on the sequence number of each pulse signal in the detection signal, the relative velocity between the target object and the MIMO millimeter-wave radar, and the transmission period of the detection signal. In this embodiment, the second value is expressed as: .in, This indicates the sequence number of chirp signals in the detected signal transmitted by the current transmitting antenna. This represents the relative velocity between the target object P and the line-of-sight direction of the MIMO millimeter-wave radar. This indicates the period of the detected signal.

[0076] Step S408: Calculate the virtual distance based on the origin distance, the first value, and the second value. In this embodiment, the virtual distance is calculated as the sum of the origin distance, the first value, and the second value. Specifically, the virtual distance is calculated according to a second formula. The second formula is: .

[0077] Please refer to the following: Figure 5 This is the fourth sub-flowchart of the signal processing method for MIMO millimeter-wave radar provided in the embodiments of this application. Step S106 specifically includes the following steps.

[0078] Step S502: Calculate the target de-modulation signal based on the reference signal and the echo signal. The reference signal includes the reference slant range. In this embodiment, the target de-modulation signal is represented as: .in, Indicates the target de-modulated signal. , . This represents the reference time delay of the reference signal. Specifically, . Indicates the reference slope distance.

[0079] The specific process of calculating the target frequency-modulated signal based on the reference signal and the echo signal will be described in detail below.

[0080] Step S504: Perform time-frequency transformation on the target demodulated signal to obtain a frequency domain signal. In this embodiment, the frequency domain signal is represented as: .in, Represents frequency domain signals, Indicates the frequency of the detected signal. This indicates the bandwidth of the detected signal. Specifically, .

[0081] Step S506: Calculate the compensation signal based on the detection delay, reference slant range, and frequency domain signal. In this embodiment, the compensation signal is represented as: .in, Indicates wave number, This represents the envelope function in the direction of the distance wavenumber. Specifically, .

[0082] The specific process of calculating the compensation signal based on the detection delay, reference slant range, and frequency domain signal will be described in detail below.

[0083] Step S508: Calculate the processing signal based on the virtual distance and the compensation signal. Substituting the virtual distance into the compensation signal yields the processing signal. In this embodiment, the processing signal is represented as: It is understandable that the processed signal consists of three components, namely, the distance from the origin. The linear phase determined by n virtual receiving channels, and the linear phase determined by the relative velocity of the target object. The linear phase is determined by the distance from the origin. The determined linear phase can determine the target distance, and the linear phase determined by n virtual receiving channels can determine the direction of arrival (DOA), which is determined by the relative velocity of the target object. The determined linear phase can determine the target velocity.

[0084] Please refer to the following: Figure 6 This is the fifth sub-flowchart of the signal processing method for MIMO millimeter-wave radar provided in the embodiments of this application. Step S502 specifically includes the following steps.

[0085] Step S602: Calculate the dot product of the conjugate complex numbers of the echo signal and the reference signal to obtain the initial demodulation signal. In this embodiment, the reference signal is represented as: .in, This represents the reference signal. The initial demodulation signal is calculated according to the third formula. Specifically, the third formula is: .in, This represents the initial de-modulation signal. This represents the conjugate complex number of the reference signal.

[0086] In this embodiment, the initial demodulation signal includes the residual video phase (RVP). The last exponential term in the initial demodulation signal is the residual video phase, which is represented as: .

[0087] Step S604: Eliminate the remaining video phase of the initial demodulated signal to obtain the target demodulated signal. In this embodiment, the deskew method can be used to eliminate the remaining video phase.

[0088] Please refer to the following: Figure 7 This is the sixth sub-flowchart of the signal processing method for MIMO millimeter-wave radar provided in the embodiments of this application. Step S506 specifically includes the following steps.

[0089] Step S702: Calculate the wavenumber signal based on the detection delay and the frequency domain signal. In this embodiment, the wavenumber signal is obtained by substituting the detection delay into the frequency domain signal. Specifically, the wavenumber signal is represented as: .

[0090] In this embodiment, wavenumber is defined. Then the wavenumber signal can be rewritten as .

[0091] Step S704: Compensate the wavenumber signal based on the reference slant range to obtain a compensated signal. In this embodiment, the reference slant range is typically... Set to 0. Even if the reference slope distance is... Not zero, but due to the reference slope distance Since it is a known quantity, the wavenumber signal can be compensated based on the reference slant range.

[0092] In this embodiment, the compensation signal is calculated according to the fourth formula. Specifically, the fourth formula is: .

[0093] Please refer to the following: Figure 8 This is the seventh sub-flowchart of the signal processing method for MIMO millimeter-wave radar provided in the embodiments of this application. Step S108 specifically includes the following steps.

[0094] Step S802, construct the objective function. In this embodiment, the objective function is expressed as: .in, Indicates the reconstruction tensor. This indicates the reconstruction of the tensor set. The tensor set representing the processed signal. Represented as a linear operator, Represents the three-dimensional tensor matrix of the completed signal. This represents the nuclear norm. This represents a regularization parameter used to strike a balance between the nuclear norm and data consistency. For Equals 1, and All are 1, 2, or 3. Represents the first element in a three-dimensional tensor matrix. List. Specifically, This is used to transform the vector of the processed signal into a Hankel matrix; . Specifically, , Among them, integers and satisfy .

[0095] In this embodiment, the objective function can be solved using an algorithm based on the alternating direction of multipliers, utilizing the exponential structure of the factor vector.

[0096] Step S804: Perform tensor completion on the processed signal according to the objective function to obtain the completed signal. In this embodiment, To reconstruct the tensor The estimated value of can be represented by tensor decomposition as follows: .in, Denotes the decomposition of tensors, symbol Denotes the outer product of vectors; for all 1 ≤ n ≤ N, the vector... Called a factor; This represents the Tucker operator.

[0097] In this embodiment, step S110 specifically includes the following steps.

[0098] The tensor decomposition of the completed signal is subjected to an inverse Fourier transform along the range wavenumber direction to obtain the range vector. Specifically, the range wavenumber vector is: .in, This represents a distance-space ambiguity function.

[0099] Assuming that the range migration does not exceed the range resolution cell, the range wavenumber vector can be approximated as: .

[0100] The detection signal sequence vector can be obtained by performing a Fourier transform on the approximate representation of the range wavenumber vector along the direction of the detection signal sequence. Specifically, the detection signal sequence vector is: .in, This represents the Doppler blur function.

[0101] The range-Doppler map for each virtual receiving channel can be obtained from the range-wavenumber vector and the detection signal sequence vector. The target object can be extracted from the range-Doppler map using a detection algorithm. The complex data of the target object in each virtual receiving channel can be used to form a receiving vector. Specifically, the receiving vector is: .in, This represents the angular ambiguity function.

[0102] Understandably, the target object eventually converges to a single point based on distance, angle, and Doppler direction, thus allowing us to obtain the target distance, target velocity, and target angle. The calculation process for target distance, target velocity, and target angle is consistent with existing methods and will not be repeated here.

[0103] like Figure 15 As shown, a simulation scenario is constructed, with a 3x3 target array arranged, and the 9 targets roughly in a square formation. The MIMO millimeter-wave radar is positioned at point O. In this simulation scenario, the MIMO millimeter-wave radar includes 6 transmitting antennas and 8 receiving antennas (e.g., ...). Figure 16 (As shown). There are 6 transmitting antennas: TX1, TX2, TX3, TX4, TX5, and TX6; and 8 receiving antennas: RX1, RX2, RX3, RX4, RX5, RX6, RX7, and RX8. The 6 transmitting antennas are evenly distributed with a spacing of 5 units between them. The eight receiving antennas are not uniformly distributed; the spacing between RX1, RX2, RX3, RX4, and RX5 is 0.5 mm. The interval between the RX6, RX7, and RX8 is 0.5. The interval between RX5 and RX6 is .

[0104] Based on the signal processing method of the aforementioned MIMO millimeter-wave radar, simulation calculations were performed on the target's range, angle, and velocity to obtain the imaging results as follows: Figure 17 As shown, all nine target points are clearly visible. If a conventional MIMO millimeter-wave radar with a 6T8R uniform array is used, the six transmitting antennas are evenly distributed with a spacing of 4... The eight receiving antennas are evenly distributed, with a spacing of 0.5 meters between each antenna. The resulting imaging result is as follows: Figure 18 As shown.

[0105] By performing a focus quality analysis on the target point located at the center of the target lattice, the angular and directional response results can be obtained, as follows: Figure 19 As shown. At -3dB, the width is 1.9°. The angular direction response results of the MIMO millimeter-wave radar with a 6T8R uniform array are as follows. Figure 20 As shown, at -3dB, the width is 2.4°. This demonstrates that a non-uniform linear array MIMO millimeter-wave radar can effectively improve angular resolution without increasing the number of antennas.

[0106] Please refer to the following: Figure 21 This is a schematic diagram of the internal structure of the main control device provided in the embodiments of this application. The main control device 10 includes a memory 11 and a processor 12. The memory 11 is used to store program instructions, and the processor 12 is used to execute the program instructions to implement the signal processing method of the MIMO millimeter-wave radar described above.

[0107] In some embodiments, the processor 12 may be a central processing unit (CPU), controller, microcontroller, microprocessor or other data processing chip, used to run program instructions stored in the memory 11.

[0108] The memory 11 includes at least one type of readable storage medium, including flash memory, hard disk, multimedia card, card-type memory (e.g., SD or DX memory), magnetic memory, magnetic disk, optical disk, etc. In some embodiments, the memory 11 may be an internal storage unit of a computer device, such as a hard disk. In other embodiments, the memory 11 may be an external storage device of a computer device, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc., provided on the computer device. Furthermore, the memory 11 may include both internal and external storage units of the computer device. The memory 11 can be used not only to store application software and various types of data installed on the computer device, such as code implementing signal processing methods for MIMO millimeter-wave radar, but also to temporarily store data that has been output or will be output.

[0109] Please refer to the following: Figure 22 This is a schematic diagram of the internal structure of the MIMO millimeter-wave radar provided in this embodiment. The MIMO millimeter-wave radar 20 includes m transmitting antennas 21, x receiving antennas 22, and a main control device 10. In this embodiment, the m transmitting antennas 21 and x receiving antennas 22 are not uniformly distributed, where m and x are both positive integers. The main control device 10 is electrically connected to the transmitting antennas 21 and the receiving antennas 22, respectively.

[0110] The specific structure of the main control device 10 is as described in the above embodiments. Since the MIMO millimeter-wave radar 20 adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0111] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

[0112] The above-listed embodiments are merely preferred embodiments of this application and should not be construed as limiting the scope of this application. Therefore, any equivalent variations made in accordance with the claims of this application shall still fall within the scope of this application.

Claims

1. A method of signal processing for a MIMO millimeter wave radar, the method comprising: The MIMO millimeter-wave radar includes m transmitting antennas and x receiving antennas, wherein the m transmitting antennas and x receiving antennas are non-uniformly distributed, and m and x are both positive integers. The signal processing method of the MIMO millimeter-wave radar includes: The m transmitting antennas are randomly controlled to transmit detection signals, and the transmitting antennas transmit signals in a random time-division manner. Calculate the echo signal formed by the reflection of the detection signal by the target object and receive it through n virtual receiving channels, wherein the x receiving antennas and the m transmitting antennas form the n virtual receiving channels, and n is equal to the product of m and x; The reference signal and the echo signal are mixed to obtain the processed signal; The processed signal is tensor-completed to obtain a completed signal; the processed signal is converted into a three-dimensional tensor of a three-dimensional receiver matrix of virtual receiver channel-detection signal sequence-range wavenumber to obtain a corresponding three-dimensional matrix diagram, which is used to fill in the blank parts of the three-dimensional matrix diagram represented by the processed signal; wherein, tensor-completed to obtain a completed signal includes: constructing an objective function; performing tensor-completed on the processed signal according to the objective function to obtain the completed signal; wherein, the objective function is expressed as: ;in, Indicates the reconstruction tensor. This indicates the reconstruction of the tensor set. This represents the tensor set of the processed signal. Represented as a linear operator, This represents the three-dimensional tensor matrix of the completed signal. Represents the nuclear norm; This represents a regularization parameter used to make a trade-off between the nuclear norm and the data for consistency; for Equals 1, and All are 1, 2, or 3. Represents the first in the three-dimensional tensor matrix List; as well as The target distance, target speed, and target angle of the target object are calculated based on the completion signal.

2. The signal processing method for MIMO millimeter-wave radar as described in claim 1, characterized in that, Calculating the echo signal formed by the reflection of the detection signal by the target object from n virtual receiving channels specifically includes: The distance between the target object and the virtual receiving channel is calculated as the virtual distance; The detection delay of the detection signal is calculated based on the virtual distance; and The echo signal is calculated based on the detection signal and the detection delay.

3. The signal processing method for MIMO millimeter-wave radar as described in claim 2, characterized in that, Before controlling the m transmitting antennas to randomly transmit detection signals, the signal processing method of the MIMO millimeter-wave radar further includes: Construct a channel coordinate axis, wherein the first virtual receiving channel among the n virtual receiving channels is located at the origin of the channel coordinate axis; The interval between the m transmitting antennas is defined as the first interval; The interval between the x receiving antennas is defined as the second interval; and Calculate the coordinates of the remaining virtual receiving channels among the n virtual receiving channels on the channel coordinate axis based on the first interval and the second interval.

4. The signal processing method for MIMO millimeter-wave radar as described in claim 3, characterized in that, Calculating the distance between the target object and the virtual receiving channel as the virtual distance specifically includes: The distance between the target object and the first virtual receiving channel in the channel coordinate axis is obtained as the origin distance; The first value is calculated based on the coordinates of the virtual receiving channel on the channel coordinate axis and the incident angle of the echo signal on the channel coordinate axis; The second value is calculated based on the sequence number of each pulse signal in the detection signal, the relative velocity between the target object and the MIMO millimeter-wave radar, and the transmission period of the detection signal; The virtual distance is calculated based on the origin distance, the first value, and the second value.

5. The signal processing method for MIMO millimeter-wave radar as described in claim 2, characterized in that, The specific steps of mixing the reference signal and the echo signal to obtain the processed signal include: The target demodulated signal is calculated based on the reference signal and the echo signal, wherein the reference signal includes a reference slant range; The target demodulated signal is subjected to time-frequency transformation to obtain a frequency domain signal; The compensation signal is calculated based on the detection delay, the reference slant range, and the frequency domain signal; and The processed signal is calculated based on the virtual distance and the compensation signal.

6. The signal processing method for MIMO millimeter-wave radar as described in claim 5, characterized in that, Calculating the target demodulated signal based on the reference signal and the echo signal specifically includes: The dot product of the conjugate complex numbers of the echo signal and the reference signal is calculated to obtain the initial demodulated signal, wherein the initial demodulated signal includes the remaining video phase; and The target demodulated signal is obtained by eliminating the remaining video phase of the initial demodulated signal.

7. The signal processing method for MIMO millimeter-wave radar as described in claim 5, characterized in that, Calculating the compensation signal based on the detection delay, the reference slant range, and the frequency domain signal specifically includes: Calculate the wavenumber signal based on the detection delay and the frequency domain signal; and The wavenumber signal is compensated based on the reference slant range to obtain the compensated signal.

8. A master control device, characterized in that, The main control device includes: Memory, used to store program instructions; and A processor for executing the program instructions to implement the signal processing method for MIMO millimeter-wave radar as described in any one of claims 1 to 7.

9. A MIMO millimeter-wave radar, characterized in that, The MIMO millimeter-wave radar includes: There are m transmitting antennas, wherein the m transmitting antennas are not uniformly distributed, and m is a positive integer; There are x receiving antennas, wherein the x receiving antennas are not uniformly distributed, and x is a positive integer; and The main control device as described in claim 8 is electrically connected to the transmitting antenna and the receiving antenna, respectively.

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