Vehicle millimeter wave radar signal processing method, device, electronic equipment and storage medium

Abstract

The embodiment of the present application provides a vehicle millimeter wave radar signal processing method, device, electronic device and storage medium, the method includes: encoding the transmission signal based on a preset coding rule combining time division multiplexing and code division multiplexing; transmitting the encoded transmission signal through a set of transmitting antennas; receiving the echo signal corresponding to the encoded transmission signal through a set of receiving antennas; the echo signal is obtained by the transmission signal based on the reflection of the object; determining the first characteristic matrix based on the echo signal; processing the first characteristic matrix through constant false alarm detection and generalized sparse decoding to determine the energy value corresponding to the object; determining the spatial position information of the object according to the energy value corresponding to the object. Through a vehicle millimeter wave radar signal processing method of the embodiment of the present application, the efficiency of the encoded transmission signal can be improved and the waveform can be prevented from being interfered.

Description

Technical Field

[0001] The present invention relates to the field of automobile technology, and in particular to a vehicle millimeter-wave radar signal processing method, device, electronic equipment and storage medium. Background Art

[0002] With the continuous development of autonomous driving technology, millimeter-wave radar is taking on increasingly important perception tasks. In the spatial perception needs of single-vehicle intelligence and vehicle-road collaboration in autonomous driving scenarios, perception data that is not affected by the environment is particularly important. Millimeter-wave radar is an active sensor that uses millimeter-level microwaves. Its data source does not rely on radiation sources and is not affected by rain, fog, or light. It has all-weather perception capabilities and has great advantages over optical sensors and laser sensors. It also has a wide ranging range, high speed and angle measurement accuracy, and can set waveform modes according to different scenarios. It is very flexible to use. Therefore, it plays an extremely important role in the field of unmanned vehicle sensors and V2X traffic sensors.

[0003] Today's MIMO imaging millimeter-wave radars usually use time division multiplexing or code division multiplexing to encode and transmit waveforms. For example, the imaging radar method of time division multiplexing is to transmit different antenna signals in a time period, and obtain information through different reception times and time domain decoding; while code division multiplexing is to transmit orthogonal waveform signals so that the signals share a bandwidth and obtain information through phase decoding. The encoding method of time division multiplexing is inefficient, covering less information per unit time, and in the code division multiplexing method, too many antennas are transmitting at the same time, which may cause interference to the waveform due to antenna coupling. Summary of the invention

[0004] In view of the defects of the prior art, the embodiments of the present disclosure provide a vehicle millimeter-wave radar signal processing method, device, electronic device and storage medium, which can improve the efficiency of coded transmission signals and avoid interference with the waveform.

[0005] An embodiment of the present application provides a vehicle millimeter-wave radar signal processing method, the method comprising: encoding a transmission signal based on a preset coding rule combining time division multiplexing and code division multiplexing; transmitting the encoded transmission signal through a transmission antenna set; receiving an echo signal corresponding to the encoded transmission signal through a receiving antenna set; the echo signal is obtained by reflecting the transmission signal based on an object; determining a first characteristic matrix based on the echo signal; processing the first characteristic matrix through constant false alarm detection and generalized sparse decoding to determine an energy value corresponding to the object; and determining the spatial position information of the object according to the energy value corresponding to the object.

[0006] Specifically, determining the first characteristic matrix based on the echo signal includes: determining a difference signal based on the transmitted signal and the echo signal; determining the second characteristic matrix by processing the difference signal through fast Fourier transform; and determining the first characteristic matrix by processing the transposed second characteristic matrix through fast Fourier transform.

[0007] Specifically, the preset coding rules for the combination of time division multiplexing and code division multiplexing include: a transmission period of the transmitted signal includes multiple subframes, each subframe includes multiple pulses; each pulse is composed of multiple sub-pulse groups, each sub-pulse group includes at least two sub-pulses; the phases of at least two sub-pulses satisfy the preset phase relationship; wherein, the transmission duration of each pulse includes multiple time divisions, and each sub-pulse group corresponds to one time division among the multiple time divisions.

[0008] Specifically, the preset phase relationship is that the phase difference between at least two sub-pulses is the preset phase difference, and the preset phase difference and each pulse are in a one-to-one correspondence; and the multiple preset phase differences corresponding to the multiple pulses are in a cyclic relationship.

[0009] Specifically, the first characteristic matrix is ​​processed through constant false alarm detection and generalized sparse decoding to determine the energy value corresponding to the object, including: based on the first characteristic matrix, an incoherent cumulative matrix is ​​determined; through constant false alarm detection, the incoherent cumulative matrix is ​​processed to determine a coordinate index set; at least two coordinate indexes that satisfy a preset coordinate relationship are determined from the coordinate index set as a target coordinate index group, and multiple target coordinate index groups constitute a target coordinate index group set; through generalized sparse decoding, the energy value corresponding to the target coordinate index group set is determined from the incoherent cumulative matrix.

[0010] Specifically, the preset coding rule combining time division multiplexing and code division multiplexing includes that the phase of the transmitted signal in each time division satisfies a preset phase relationship; and the preset coordinate relationship is determined based on the preset phase relationship.

[0011] Specifically, the preset coding rules for the combination of time division multiplexing and code division multiplexing include that the phase of the transmitted signal in each time division satisfies a preset phase relationship; through generalized sparse decoding, the energy value corresponding to the target coordinate index group set is determined from the incoherent accumulation matrix, including: determining the absolute value of the matrix element corresponding to the target coordinate index group set from the incoherent accumulation matrix; based on the preset phase relationship, phase compensation is performed on the absolute value of the matrix element corresponding to the target coordinate index group set to determine the energy value corresponding to the target coordinate index group set.

[0012] Accordingly, an embodiment of the present application provides a vehicle millimeter-wave radar signal processing device, which includes: a coding module, which is used to encode a transmission signal based on a preset coding rule combining time division multiplexing and code division multiplexing; a transmitting module, which is used to transmit the encoded transmission signal through a transmitting antenna set; a receiving module, which is used to receive an echo signal corresponding to the encoded transmission signal through a receiving antenna set; the echo signal is obtained by reflecting the transmission signal based on an object; a characteristic matrix determination module, which is used to determine a first characteristic matrix based on the echo signal; an energy value determination module, which is used to process the first characteristic matrix through constant false alarm detection and generalized sparse decoding to determine the energy value corresponding to the object; and a calculation module, which is used to determine the spatial position information of the object according to the energy value corresponding to the object.

[0013] Specifically, the characteristic matrix determination module is used to determine the difference signal based on the transmission signal and the echo signal; determine the second characteristic matrix by processing the difference signal through fast Fourier transform; and determine the first characteristic matrix by processing the transposed second characteristic matrix through fast Fourier transform.

[0014] Specifically, the preset coding rules for the combination of time division multiplexing and code division multiplexing include: a transmission period of the transmitted signal includes multiple subframes, each subframe includes multiple pulses; each pulse is composed of multiple sub-pulse groups, each sub-pulse group includes at least two sub-pulses; the phases of at least two sub-pulses satisfy the preset phase relationship; wherein, the transmission duration of each pulse includes multiple time divisions, and each sub-pulse group corresponds to one time division among the multiple time divisions.

[0015] Specifically, the preset phase relationship is that the phase difference between at least two sub-pulses is the preset phase difference, and the preset phase difference and each pulse are in a one-to-one correspondence; and the multiple preset phase differences corresponding to the multiple pulses are in a cyclic relationship.

[0016] Specifically, the energy value determination module is used to determine the incoherent cumulative matrix based on the first characteristic matrix; the incoherent cumulative matrix is ​​processed through constant false alarm detection to determine the coordinate index set; at least two coordinate indexes that satisfy a preset coordinate relationship are determined from the coordinate index set as a target coordinate index group, and multiple target coordinate index groups constitute a target coordinate index group set; through generalized sparse decoding, the energy value corresponding to the target coordinate index group set is determined from the incoherent cumulative matrix.

[0017] Specifically, the preset coding rule combining time division multiplexing and code division multiplexing includes that the phase of the transmitted signal in each time division satisfies a preset phase relationship; and the preset coordinate relationship is determined based on the preset phase relationship.

[0018] Specifically, the preset coding rules combining time division multiplexing and code division multiplexing include that the phase of the transmitted signal in each time division satisfies a preset phase relationship; the energy value determination module is used to determine the absolute values ​​of the matrix elements corresponding to the target coordinate index group set from the incoherent accumulation matrix; based on the preset phase relationship, the absolute values ​​of the matrix elements corresponding to the target coordinate index group set are phase compensated to determine the energy value corresponding to the target coordinate index group set.

[0019] Accordingly, the present application provides an electronic device, including a processor and a memory, wherein the memory stores at least one instruction, at least one program, code set or instruction set, and the at least one instruction, at least one program, code set or instruction set is loaded and executed by the processor to implement the above-mentioned vehicle millimeter-wave radar signal processing method.

[0020] Accordingly, an embodiment of the present disclosure provides a computer-readable storage medium, in which at least one instruction, at least one program, code set or instruction set is stored, and the at least one instruction, at least one program, code set or instruction set is loaded and executed by a processor to implement the above-mentioned vehicle millimeter-wave radar signal processing method.

[0021] The embodiments of the present application have the following beneficial effects:

[0022] (1) Encode radar transmission signals by combining time division multiplexing and code division multiplexing to avoid the drawbacks of using only one coding method, including the low transmission efficiency of time division multiplexing and the inaccurate waveform caused by antenna waveform coupling of code division multiplexing;

[0023] (2) When time division multiplexing and code division multiplexing are combined to encode the transmitted signal, the amount of calculation and storage can be reduced by generalized sparse decoding of the echo signal, thus avoiding unnecessary waste of computing power. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 It is a schematic diagram of an application scenario of a vehicle millimeter-wave radar signal processing method provided in an embodiment of the present application;

[0026] Figure 2 It is a first flow chart of a vehicle millimeter wave radar signal processing method provided in an embodiment of the present application;

[0027] Figure 3It is a second flow chart of a vehicle millimeter wave radar signal processing method provided in an embodiment of the present application;

[0028] Figure 4 It is a third flow chart of a vehicle millimeter wave radar signal processing method provided in an embodiment of the present application;

[0029] Figure 5 It is a schematic diagram of a single pulse transmission scheme of a vehicle millimeter wave radar signal processing method provided in an embodiment of the present application;

[0030] Figure 6 It is a schematic diagram of a single pulse transmission waveform of a vehicle millimeter wave radar signal processing method provided in an embodiment of the present application;

[0031] Figure 7 It is a schematic diagram of Doppler coding phase difference of a vehicle millimeter wave radar signal processing method provided in an embodiment of the present application;

[0032] Figure 8 It is a schematic diagram of the incoherent accumulation result of a vehicle millimeter wave radar signal processing method provided in an embodiment of the present application;

[0033] Fig. 9 It is a structural schematic diagram of a vehicle millimeter wave radar signal processing device provided in an embodiment of the present application;

[0034] Fig.10 This is a hardware structure block diagram of a server of a vehicle millimeter-wave radar signal processing method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical scheme and advantages of the present application clearer, the embodiments of the present application will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiment is only one embodiment of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0036] The "embodiment" referred to herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present application. In the description of the embodiments of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "top", "bottom", etc. is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device / system or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present application. The terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may include one or more of the features explicitly or implicitly. Moreover, the terms "first", "second", etc. are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described here can be implemented in an order other than that illustrated or described here. In addition, the terms "including" and "having" / "for" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system / apparatus, product or apparatus comprising a series of steps or units / modules is not necessarily limited to those steps or units / modules explicitly listed, but may include other steps or units / modules not explicitly listed or inherent to such process, method, product or apparatus.

[0037] See also Figure 1 , Figure 1 is a schematic diagram of an application scenario of a vehicle millimeter wave radar signal processing method provided in an embodiment of the present application, such as Figure 1 As shown in the figure, the left side of the arrow is the vehicle 101, and the right side is the structural diagram of the vehicle 101. The scene may include the vehicle 101, and the vehicle 101 includes a vehicle millimeter wave radar 1011. The number of the vehicle millimeter wave radars 1011 can be multiple, and they can be located at the four corners and the front of the vehicle 101. Specifically, in the application scenario of the present application, a vehicle millimeter wave radar signal processing method of the present application can be applied to the vehicle 101 to set the transmission signal encoding method and the echo signal processing method of the vehicle millimeter wave radar 1011.

[0038] The following describes an exemplary process of a vehicle millimeter wave radar signal processing method provided by the present application. In the method embodiment of the present application, the execution subject may be a vehicle or a vehicle millimeter wave radar signal processing device. Figure 2This is a first flow chart of a vehicle millimeter-wave radar signal processing method provided in an embodiment of the present application. This specification provides method or process operation steps as shown in the embodiment or flow chart, but may include more or fewer operation steps based on conventional or non-creative labor. The order of steps listed in the embodiment is only one of many execution orders and does not represent the only execution order. In actual execution, the method or process sequence shown in the embodiment or the accompanying drawings may be executed or executed in parallel (for example, in a parallel processor or multi-threaded processing environment). Specifically, Figure 2 As shown, the method includes:

[0039] The present application provides a vehicle millimeter wave radar signal processing method, the method comprising:

[0040] S201: Encode a transmission signal based on a preset encoding rule combining time division multiplexing and code division multiplexing.

[0041] Specifically, the transmission signal may be a linear frequency modulation signal, that is, the frequency of the transmission signal increases linearly with time within a period.

[0042] In a specific implementation, the combination of time division multiplexing and code division multiplexing refers to transmitting different antenna signals in multiple time divisions of a time period, and transmitting waveforms with different phases in a time period, that is, encoding using both time division multiplexing and code division multiplexing principles.

[0043] Specifically, the preset coding rules combining time division multiplexing and code division multiplexing include: a transmission cycle of the transmission signal includes multiple subframes, each subframe includes multiple pulses; each pulse is composed of multiple sub-pulse groups, each sub-pulse group includes at least two sub-pulses; the phases of at least two sub-pulses satisfy the preset phase relationship; wherein, the transmission duration of each pulse includes multiple time divisions, and each sub-pulse group corresponds to one of the multiple time divisions. For all transmitting antennas, each transmitting antenna can be controlled to transmit a sub-pulse in only one of the multiple time divisions, that is, if the transmitting antenna transmits a sub-pulse in the one time division, then except for the one time division, the corresponding transmitting antenna does not transmit a sub-pulse in other time divisions. The preset phase relationship can be that the phase difference between at least two sub-pulses is the preset phase difference, and the preset phase difference and each pulse are in a one-to-one correspondence; the multiple preset phase differences corresponding to multiple pulses are in a cyclic relationship.

[0044] In a specific implementation, the radar can adopt a four-chip cascaded transceiver mode, using a total of 12 transmitting antennas and 16 receiving antennas, wherein a single chip has 3 transmitting antennas and 4 receiving antennas. The transmitting antennas are set with serial numbers 1 to 12 from left to right.

[0045] Combine the following Figure 5 , Figure 6 and Figure 7 The encoding method of the transmitted signal is further explained.

[0046] Figure 5 It is a schematic diagram of a single pulse transmission scheme of a vehicle millimeter wave radar signal processing method provided in an embodiment of the present application; Figure 6 It is a schematic diagram of a single pulse transmission waveform of a vehicle millimeter wave radar signal processing method provided in an embodiment of the present application; Figure 7 It is a schematic diagram of Doppler coding phase difference of a vehicle millimeter wave radar signal processing method provided in an embodiment of the present application.

[0047] Specifically, the launch scheme can be as follows Figure 5 As shown, in the transmission waveform used, a frame of complete radar data may contain 64, 128, 256 or 2^N pulses. Each pulse may be composed of 12 sub-pulse groups, wherein each sub-pulse is transmitted by one of the 12 transmitting antennas. Each sub-pulse group may include 2 sub-pulses; the phases of the 2 sub-pulses satisfy a preset phase relationship; wherein the transmission duration of each pulse includes 6 time divisions, and each sub-pulse group may correspond to one of the 6 time divisions. As shown in the attached Figure 5 and attached Figure 6 As shown in the figure, transmitting antenna 1 and transmitting antenna 4, transmitting antenna 7 and transmitting antenna 10, transmitting antenna 2 and transmitting antenna 5, transmitting antenna 8 and transmitting antenna 11, transmitting antenna 3 and transmitting antenna 6, transmitting antenna 9 and transmitting antenna 12 are 6 sub-pulse groups respectively, and correspond to 6 time divisions in sequence. Figure 5 The diagram shows the sub-pulse emission timing within a single pulse. Each sub-pulse group can be emitted in sequence in a time-sharing order from left to right. Figure 6 The diagram shows the waveform setting of a single pulse. The six cells from left to right correspond to the six time divisions described above, and in each of the six cells, the upper and lower sub-pulse waveforms can correspond to a sub-pulse group, that is, the six cells correspond to transmitting antenna 1 and transmitting antenna 4, transmitting antenna 7 and transmitting antenna 10, transmitting antenna 2 and transmitting antenna 5, transmitting antenna 8 and transmitting antenna 11, transmitting antenna 3 and transmitting antenna 6, transmitting antenna 9 and transmitting antenna 12, respectively.

[0048] Figure 7The diagram shows a specific Doppler phase difference encoding scheme. For a single pulse, the preset phase difference corresponding to each pulse may refer to the phase difference between two sub-pulses in each sub-pulse group in each pulse, and the preset phase difference may be a fixed value; and a frame of radar data includes multiple pulses, and the above phase difference may be a cyclic phase difference between multiple pulses. Specifically, the first transmission channel is normal transmission, and the second transmission channel performs Doppler phase encoding, and the phase encoding changes with the number of Doppler channels. The antenna transmission waveform in a single subframe is as follows: Figure 7 As shown in the figure, the cyclic phase difference can be a cycle of 0, 0.5pi, pi, 1.5pi. That is to say, when Doppler phase encoding is performed on the sub-pulse group within each pulse, it can start from the first pulse, with four pulses as a group, and the preset phase difference of each four pulses is 0, 0.5pi, pi, 1.5pi respectively, and this pattern is repeated until the 128th pulse.

[0049] The disadvantages of using only time division multiplexing or only code division multiplexing for encoding can be avoided by using a coding method that combines time division multiplexing and code division multiplexing. If only time division multiplexing is used for encoding, the antenna utilization rate will be too low due to the need to transmit signals in time division, and less effective information will be transmitted per unit time; if only code division multiplexing is used for encoding, although waveforms of different phases are transmitted at the same time, due to the limited radar transmission capability, the transmitting antennas will affect each other and coupling will occur, and the antenna power pattern will be invalid, and will not be transmitted according to the established pattern, resulting in confusion of the side lobes that should be converged and excessive side lobe power. At the same time, multiple channels of original radar data will be generated during decoding, occupying a large amount of storage resources. The embodiment of the present application adopts a coding method that combines time division multiplexing and code division multiplexing, which can not only improve the antenna utilization rate, but also reduce the error caused by antenna coupling.

[0050] S202: Transmit the encoded transmission signal through a set of transmitting antennas.

[0051] Specifically, the number of transmitting antennas may be 12.

[0052] S203: receiving an echo signal corresponding to the encoded transmission signal through a receiving antenna set; the echo signal is obtained by reflecting the transmission signal from an object.

[0053] In a specific implementation, the object may be one or more objects. The number of receiving antennas may be 16.

[0054] S204: Determine a first characteristic matrix based on the echo signal.

[0055] Combine the following Figure 3 Step S204 is further described.

[0056] Figure 3 2 is a schematic diagram of a second flow chart of a vehicle millimeter wave radar signal processing method provided in an embodiment of the present application. Figure 3 As shown, the exemplary process of step S204 may include:

[0057] S301: Determine a difference signal based on a transmission signal and an echo signal.

[0058] Specifically, the frequency and phase of the echo signal and the transmission signal may be respectively subtracted, and the results of the subtraction are the frequency and phase of the difference signal, and finally the difference signal is obtained.

[0059] S302: Process the difference signal by fast Fourier transform to determine a second characteristic matrix.

[0060] Specifically, a 1028-point FFT (Fast Fourier Transform) transform can be performed on each echo ADC (Analog to Digital Converter) sampling data of each group of receiving antennas of the radar. In addition, since the ADC sampling data is a real sampling signal with symmetrical characteristics, the first 512-point FFT transformation results can be intercepted as the distance dimension FFT result. In a specific implementation, a frame of radar data includes 128 pulses, then in step S302, the 128 echo ADC sampling data can be FFT transformed, and a total of 128 512-point distance dimension FFT results can be obtained. The 128 512-point distance dimension FFT results are arranged in the order of the year, and a 128*512 matrix can be obtained as the second characteristic matrix.

[0061] Specifically, before performing FFT transformation, the ADC sampling data may be demodulated, filtered, and de-carriered.

[0062] S303: Processing the transposed second characteristic matrix by fast Fourier transform to determine the first characteristic matrix.

[0063] Specifically, the transposed second characteristic matrix can be subjected to Doppler FFT transformation in the Doppler dimension, that is, the 512*128 matrix is ​​subjected to Doppler FFT transformation to obtain 512 two-dimensional FFT transformation results; thus, by integrating the 512 two-dimensional matrices, three-dimensional cube data can be obtained as the first characteristic matrix. The x coordinate is the number of FFT points or distance units in the distance dimension, that is, 128; the y coordinate is the number of Doppler FFT points, or the number of Doppler units, that is, 512; the z coordinate is the number of antenna dimension points, that is, the number of transmitting antennas*the number of receiving antennas / 2 points. In the embodiment of 12 transmitting antennas and 16 receiving antennas, the number of antenna dimension points can be 96.

[0064] S205: Processing the first feature matrix through constant false alarm detection and generalized sparse decoding to determine an energy value corresponding to the object.

[0065] Combine the following Figure 4 Step S205 is further described.

[0066] Figure 4 FIG. 3 is a third flow chart of a vehicle millimeter wave radar signal processing method provided in an embodiment of the present application. Figure 4 As shown, the exemplary process of step S205 may include:

[0067] S401: Determine a non-coherent accumulation matrix based on the first characteristic matrix.

[0068] Specifically, the absolute values ​​of all elements of the first characteristic matrix can be calculated to obtain an incoherent accumulation matrix. The elements in the first characteristic matrix can be in complex form. Among them, the incoherent accumulation matrix is ​​a three-dimensional cube matrix, and the coordinates of the x, y, and z axes can be consistent with the first characteristic matrix respectively. The elements in the incoherent accumulation matrix can represent the incoherent accumulation result.

[0069] S402: Process the incoherent accumulation matrix through constant false alarm detection to determine a coordinate index set.

[0070] Specifically, the non-coherent accumulation matrix can be used as the input signal through constant false alarm detection to process the noise in the input signal. Then, a threshold is determined, and the threshold is compared with the input signal. If the input signal exceeds the threshold, it is judged as a target, otherwise, it is judged as no target. Based on this, a coordinate index set is determined based on the coordinate index of the target. The coordinate index is used to represent the coordinate corresponding to the target in the non-coherent accumulation matrix, and the coordinate can be in the form of (x, y, z).

[0071] S403: Determine at least two coordinate indexes satisfying a preset coordinate relationship from the coordinate index set as a target coordinate index group, and multiple target coordinate index groups constitute a target coordinate index group set.

[0072] Specifically, the target coordinate index may be found from the coordinate index set.

[0073] In a specific implementation, a non-coherent result graph of the number of transmitting antennas * the number of receiving antennas / 2 can be formed based on the non-coherent accumulation matrix, and each result graph is determined based on the x-coordinate, the y-coordinate and the corresponding non-coherent result; that is, the non-coherent accumulation matrix can be divided into a two-dimensional matrix of the number of transmitting antennas * the number of receiving antennas / 2 with each z-axis coordinate as a unit, and these two-dimensional matrices are converted into the form of a non-coherent result graph. At a time, a single target will have two energy peaks in the non-coherent result graph, one representing the result of the first transmission channel, and the other representing the result of another transmission channel transmitted at the same time. For a single target, the two elements corresponding to the two transmission channels can have a preset coordinate relationship between the coordinates in the non-coherent accumulation matrix. When the Doppler coding cycle phase difference is 0.5pi, the preset coordinate relationship can be that the coordinate difference of the Doppler unit is 32 cells. All coordinate indexes in the coordinate index set can be traversed, and if there are elements corresponding to two coordinate indexes that satisfy the preset coordinate relationship, it is determined that the element corresponds to the target rather than interference or noise, and the two coordinate indexes are determined to be the target coordinate index group.

[0074] In a specific embodiment, the preset coding rule combining time division multiplexing and code division multiplexing includes that the phase of the transmitted signal in each time division satisfies the preset phase relationship; the preset coordinate relationship is determined based on the preset phase relationship. In the above embodiment where the phase difference of the Doppler unit is 32 cells, the 32 cells are determined by multiplying 128 Doppler cells by 0.5pi divided by 2pi. Specifically, when the Doppler coding cycle phase difference is pi, the amount of the phase difference of the Doppler unit is 64 cells.

[0075] S404: Determine the energy value corresponding to the target coordinate index group set from the incoherent accumulation matrix through generalized sparse decoding.

[0076] Specifically, the elements corresponding to the coordinate indexes other than the target coordinate index group can be deleted from the incoherent accumulation matrix to obtain the target accumulation matrix. Then, in the target accumulation matrix, the energy value corresponding to the target coordinate index group set can be obtained by performing phase compensation on the corresponding elements in each target coordinate index group. The energy value corresponding to the target coordinate index group set is the energy value corresponding to the object.

[0077] Phase compensation can be a correction of the phase, that is, multiplying the element or result corresponding to the transmission channel by jθ, where θ is the coding phase difference between the transmission channel and the first transmission channel in a sub-pulse group during Doppler coding. That is to say, in an embodiment where the coding phase difference is 0.5π, phase compensation can be performed by multiplying the element corresponding to the second transmission channel, that is, the element with a relatively large Doppler unit, by j0.5π. In a specific embodiment, when encoding the transmission signal, multiple transmission channels can be transmitted simultaneously in one time division, and at this time, phase compensation is to multiply the elements corresponding to all transmission channels except the first transmission channel by jθ.

[0078] Combine the following Figure 8 Further elaboration of the incoherent accumulation results.

[0079] Figure 8 FIG. 1 is a schematic diagram of the incoherent accumulation result of a vehicle millimeter wave radar signal processing method provided in an embodiment of the present application. Figure 8 As shown in the figure, Figure 8 Taking a set of target coordinate index groups in as an example, two points in the incoherent result graph can represent the elements corresponding to the two transmission channels, corresponding to a target coordinate index group. One is the unshifted data and the other is the Doppler shifted data, which come from two different transmitting antennas in a time-sharing manner. Figure 8 The horizontal axis of the diagram is the Doppler dimension, also known as the slow time dimension. Its data meaning is the number of sampling data points. Its physical meaning in the radar is related to the target speed. That is, the target speed information can be calculated based on the coordinates of the Doppler dimension. The vertical axis of the diagram is the distance dimension, also known as the fast time dimension. Its data meaning is the number of pulses. Its physical meaning is related to the target distance. That is, the target distance information can be calculated based on the coordinates of the distance dimension. Figure 8 In the embodiment shown in , generalized sparse decoding can be to perform phase compensation processing on the second element of the two elements in the incoherent result graph of each transceiver channel, and finally obtain two energy values. The energy value can be used to characterize the spatial phase information of the object. The energy value results of all transceiver channels of an object can be determined as the energy value corresponding to the object.

[0080] In a specific implementation, there may be only one object in the space around the vehicle radar. Under ideal conditions without considering interference, only one distance dimension coordinate exists in the second characteristic matrix obtained by the first FFT transformation, and the distance dimension coordinate can be used to calculate the distance of the object; only one distance dimension coordinate and two Doppler dimension coordinates exist in the first characteristic matrix obtained by the second FFT transformation. After phase compensation of the second result point, the Doppler dimension coordinate can be used to calculate the speed of the object, and the energy value obtained after phase compensation can be used for subsequent calculation of other parameter information of the target, such as spatial position information.

[0081] Through generalized sparse decoding, multiple target points formed by one target can be used to construct a secondary data source; traditional decoding only uses one target point to construct a data source. If the traditional encoding and decoding method is used, in a scenario with 12 transmitting antennas and 16 receiving antennas, it is necessary to decode the FFT result matrix after the first FFT transformation, decode one copy of the original data to obtain two channel data, thus generating 192 Figure 8 However, since the embodiment of the present application uses multiple encoding methods and decodes through generalized sparse decoding, only 96 images need to be generated. Figure 4 , greatly reducing the amount of calculation and storage.

[0082] It should be noted that the present application does not limit the number of sub-pulses in the sub-pulse group during encoding. The above description uses 2 as an example, but in some other specific implementations, the number of sub-pulses in the sub-pulse group can also be other numbers. When the number of sub-pulse groups is N, the number of elements in each non-coherent accumulation result diagram is also N, and the amount of calculation and storage in the decoding process can be reduced by N-1 / N. Specifically, setting more transmission channels for simultaneous transmission can save the amount of calculation and storage to a greater extent.

[0083] S206: Determine the spatial position information of the object according to the energy value corresponding to the object.

[0084] Specifically, the secondary arrival angle estimation can be performed based on the energy value corresponding to the object. The energy value corresponding to the object can include the energy value groups of the antenna dimension points of all objects. The phase information of the target point can be obtained through these energy values, so as to estimate the target calculation parameters, such as the horizontal angle and the pitch angle, and form a spatial point cloud and model it into spatial imaging.

[0085] Accordingly, the present application provides a vehicle millimeter-wave radar signal processing device. Fig. 9 Schematic diagram of the structure of a vehicle millimeter wave radar signal processing device provided in an embodiment of the present application. Fig. 9 As shown, the vehicle millimeter wave radar signal processing device 900 includes:

[0086] The encoding module 901 is used to encode the transmission signal based on a preset encoding rule combining time division multiplexing and code division multiplexing;

[0087] A transmitting module 902, configured to transmit the encoded transmission signal through a transmitting antenna set;

[0088] The receiving module 903 is used to receive the echo signal corresponding to the encoded transmission signal through the receiving antenna set; the echo signal is obtained by reflecting the transmission signal from the object;

[0089] A characteristic matrix determination module 904, configured to determine a first characteristic matrix based on the echo signal;

[0090] An energy value determination module 905 is used to process the first feature matrix through constant false alarm detection and generalized sparse decoding to determine the energy value corresponding to the object;

[0091] The calculation module 906 is used to determine the spatial position information of the object according to the energy value corresponding to the object.

[0092] Specifically, the characteristic matrix determination module 904 can be used to determine the difference signal based on the transmission signal and the echo signal; determine the second characteristic matrix by processing the difference signal through fast Fourier transform; and determine the first characteristic matrix by processing the transposed second characteristic matrix through fast Fourier transform.

[0093] Specifically, the preset coding rules combining time division multiplexing and code division multiplexing may include: a transmission period of the transmitted signal includes multiple subframes, each subframe includes multiple pulses; each pulse is composed of multiple sub-pulse groups, each sub-pulse group includes at least two sub-pulses; the phases of at least two sub-pulses satisfy a preset phase relationship; wherein the transmission duration of each pulse includes multiple time divisions, and each sub-pulse group corresponds to one time division among the multiple time divisions.

[0094] Specifically, the preset phase relationship is that the phase difference between at least two sub-pulses is the preset phase difference, and the preset phase difference and each pulse are in a one-to-one correspondence; and the multiple preset phase differences corresponding to the multiple pulses are in a cyclic relationship.

[0095] Specifically, the energy value determination module 905 can be used to determine an incoherent cumulative matrix based on a first characteristic matrix; process the incoherent cumulative matrix through constant false alarm detection to determine a coordinate index set; determine at least two coordinate indexes that satisfy a preset coordinate relationship from the coordinate index set as a target coordinate index group, and multiple target coordinate index groups constitute a target coordinate index group set; determine the energy value corresponding to the target coordinate index group set from the incoherent cumulative matrix through generalized sparse decoding.

[0096] Specifically, the preset coding rule combining time division multiplexing and code division multiplexing may include that the phase of the transmitted signal in each time division satisfies a preset phase relationship; and the preset coordinate relationship is determined based on the preset phase relationship.

[0097] Specifically, the preset coding rules combining time division multiplexing and code division multiplexing may include that the phase of the transmitted signal in each time division satisfies a preset phase relationship; the energy value determination module is used to determine the absolute value of the matrix elements corresponding to the target coordinate index group set from the incoherent accumulation matrix; based on the preset phase relationship, the absolute value of the matrix elements corresponding to the target coordinate index group set is phase compensated to determine the energy value corresponding to the target coordinate index group set.

[0098] The device and method embodiments in the embodiments of the present application are based on the same application concept.

[0099] The method embodiments provided in the embodiments of the present application can be executed in a computer terminal, a server or a similar computing device. Taking running on a server as an example, Fig.10 FIG. 1 is a hardware structure diagram of a server of a vehicle millimeter wave radar signal processing method provided in an embodiment of the present application. Fig.10 As shown, the server 1000 may have relatively large differences due to different configurations or performances, and may include one or more central processing units (CPU) 1010 (the central processing unit 1010 may include but is not limited to a processing device such as a microprocessor MCU or a programmable logic device FPGA), a memory 1030 for storing data, and one or more storage media 1020 (such as one or more mass storage devices) for storing application programs 1023 or data 1022. Among them, the memory 1030 and the storage medium 1020 can be short-term storage or permanent storage. The program stored in the storage medium 1020 may include one or more modules, each of which may include a series of instruction operations on the server. Furthermore, the central processing unit 1010 can be configured to communicate with the storage medium 1020 and execute a series of instruction operations in the storage medium 1020 on the server 1000. The server 800 may also include one or more power supplies 860, one or more wired or wireless network interfaces 850, one or more input and output interfaces 1040, and / or one or more operating systems 1021, such as Windows ServerTM, Mac OSXTM, UnixTM, LinuxTM, FreeBSDTM, etc.

[0100] The input / output interface 1040 may be used to receive or send data via a network. The specific example of the network may include a wireless network provided by a communication provider of the server 1000. In one example, the input / output interface 1040 includes a network adapter (Network Interface Controller, NIC), which may be connected to other network devices through a base station so as to communicate with the Internet. In one example, the input / output interface 1040 may be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0101] It can be understood by those skilled in the art that Fig.10 The structure shown is only for illustration and does not limit the structure of the above electronic device. Fig.10 More or fewer components as shown, or with Fig.10 Different configurations are shown.

[0102] An embodiment of the present application also provides an electronic device, including a processor and a memory, wherein the memory stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, at least one program, a code set or an instruction set is loaded and executed by the processor to implement the above-mentioned vehicle millimeter-wave radar signal processing method.

[0103] The present application implements a storage medium, which can be set in a server to store at least one instruction, at least one program, code set or instruction set related to the vehicle millimeter wave radar signal processing method in the method embodiment. The at least one instruction, the at least one program, the code set or instruction set is loaded and executed by the processor to implement the above-mentioned vehicle millimeter wave radar signal processing method.

[0104] Specifically, in this embodiment, the storage medium may be located in at least one of the multiple network servers of the computer network. Optionally, in this embodiment, the storage medium may include, but is not limited to, various media that can store program codes, such as a USB flash drive, a read-only memory (ROM), a mobile hard disk, a magnetic disk, or an optical disk.

[0105] In the present invention, unless otherwise clearly specified and limited, the terms "connected", "connection" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be a connection between two elements or an interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0106] It should be noted that the order of the above embodiments of the present application is only for description and does not represent the advantages and disadvantages of the embodiments. The above description describes specific embodiments, and other embodiments are also within the scope of the attached claims. In some cases, the actions or steps recorded in the claims can be performed in the order of different embodiments and can achieve the expected results. In addition, the processes depicted in the drawings do not necessarily require a specific order or connection order to achieve the desired results. In some embodiments, multi-task parallel processing is also possible or may be advantageous.

[0107] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the embodiments of the device / system, since they are based on similarities to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiments.

[0108] The above are preferred embodiments of the present invention. It should be noted that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A vehicle millimeter wave radar signal processing method, characterized in that: The method comprises: Encoding the transmission signal based on a preset encoding rule combining time division multiplexing and code division multiplexing; Transmitting the encoded transmission signal through a set of transmitting antennas; Receiving an echo signal corresponding to the encoded transmission signal through a receiving antenna set; the echo signal is obtained by reflecting the transmission signal from an object; determining a first characteristic matrix based on the echo signal; Processing the first feature matrix through constant false alarm detection and generalized sparse decoding to determine an energy value corresponding to the object; Determine the spatial position information of the object according to the energy value corresponding to the object; The preset coding rules for combining time division multiplexing and code division multiplexing include: One transmission cycle of the transmission signal includes a plurality of subframes, and each subframe includes a plurality of pulses; Each pulse is composed of a plurality of sub-pulse groups, each sub-pulse group includes at least two sub-pulses; the phases of the at least two sub-pulses satisfy a preset phase relationship; the preset phase relationship is that the phase difference of at least two sub-pulses is a preset phase difference, and the preset phase difference and each pulse are in a one-to-one correspondence; the plurality of preset phase differences corresponding to the plurality of pulses are in a cyclic relationship; when the plurality of sub-pulse groups are Doppler phase encoded, the preset phase difference corresponding to each pulse in the sub-pulse group is circulated; The emission duration of each pulse includes multiple time divisions, and each sub-pulse group corresponds to one time division among the multiple time divisions.

2. The vehicle millimeter wave radar signal processing method according to claim 1, characterized in that: Determining a first characteristic matrix based on the echo signal includes: Determining a difference signal based on the transmit signal and the echo signal; Processing the difference signal by fast Fourier transform to determine a second characteristic matrix; The first characteristic matrix is ​​determined by processing the transposed second characteristic matrix through fast Fourier transform.

3. The vehicle millimeter wave radar signal processing method according to claim 1, characterized in that: The first feature matrix is ​​processed by constant false alarm detection and generalized sparse decoding to determine the energy value corresponding to the object, including: Based on the first characteristic matrix, determining a non-coherent accumulation matrix; Processing the incoherent accumulation matrix through constant false alarm detection to determine a coordinate index set; Determine at least two coordinate indexes satisfying a preset coordinate relationship from the coordinate index set as a target coordinate index group, wherein a plurality of the target coordinate index groups constitute a target coordinate index group set; The energy value corresponding to the target coordinate index group set is determined from the incoherent accumulation matrix through generalized sparse decoding.

4. The vehicle millimeter wave radar signal processing method according to claim 3, characterized in that: The preset coding rule combining time division multiplexing and code division multiplexing includes that the phase of the transmitted signal in each time division satisfies a preset phase relationship; and the preset coordinate relationship is determined based on the preset phase relationship.

5. The vehicle millimeter wave radar signal processing method according to claim 3, characterized in that: The preset coding rule combining time division multiplexing and code division multiplexing includes that the phase of the transmission signal in each time division satisfies a preset phase relationship; The step of determining the energy value corresponding to the target coordinate index group set from the incoherent accumulation matrix by generalized sparse decoding includes: Determine the absolute value of the matrix element corresponding to the target coordinate index group set from the incoherent accumulation matrix; Based on the preset phase relationship, phase compensation is performed on the absolute values ​​of the matrix elements corresponding to the target coordinate index group set to determine the energy value corresponding to the target coordinate index group set.

6. A vehicle millimeter wave radar signal processing device, characterized in that: The device comprises: A coding module, used for encoding the transmission signal based on a preset coding rule combining time division multiplexing and code division multiplexing; A transmitting module, used for transmitting the encoded transmission signal through a set of transmitting antennas; A receiving module, configured to receive an echo signal corresponding to the encoded transmission signal through a receiving antenna set; the echo signal is obtained by reflecting the transmission signal from an object; A characteristic matrix determination module, used to determine a first characteristic matrix based on the echo signal; An energy value determination module, used to process the first feature matrix through constant false alarm detection and generalized sparse decoding to determine the energy value corresponding to the object; A calculation module, used to determine the spatial position information of the object according to the energy value corresponding to the object; The preset coding rules for combining time division multiplexing and code division multiplexing include: One transmission cycle of the transmission signal includes a plurality of subframes, and each subframe includes a plurality of pulses; Each pulse is composed of a plurality of sub-pulse groups, each sub-pulse group includes at least two sub-pulses; the phases of the at least two sub-pulses satisfy a preset phase relationship; the preset phase relationship is that the phase difference between the at least two sub-pulses is a preset phase difference, and the preset phase difference is in a one-to-one correspondence with each pulse; the multiple preset phase differences corresponding to the multiple pulses are in a cyclic relationship; The emission duration of each pulse includes multiple time divisions, and each sub-pulse group corresponds to one time division among the multiple time divisions.

7. An electronic device, characterized in that: The electronic device includes a processor and a memory, wherein the memory stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, the at least one program, the code set or the instruction set is loaded and executed by the processor to implement the vehicle millimeter-wave radar signal processing method according to any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that: The storage medium stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, the at least one program, the code set or the instruction set is loaded and executed by the processor to implement the vehicle millimeter-wave radar signal processing method as described in any one of claims 1 to 5.

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