Signal processing method, system, chip, readable storage medium and program product

Abstract

The present application relates to a signal processing method, system, chip, readable storage medium and program product. The method comprises: obtaining a current frame digital signal determined based on a target reflection echo; determining a first radial distance dimension spectrum corresponding to the current frame digital signal; obtaining target state information of the target in the previous frame, performing slow-time linear phase compensation on the first radial distance dimension spectrum according to the target state information, and obtaining a second radial distance dimension spectrum; determining a radial relative velocity spectrum based on the second radial distance dimension spectrum, performing incoherent accumulation, obtaining a final radial distance-radial relative velocity spectrum, performing target detection on the spectrum, and determining the radial distance index value and radial relative velocity index value of the target. The use of this method can reduce the broadening of the main lobe of the radial relative velocity dimension and reduce the risk of missed detection of different targets.

Description

Technical Field

[0001] The present application relates to the field of radar technology, and in particular to a signal processing method, system, chip, readable storage medium and program product. Background Art

[0002] With the popularization and development of intelligent driving technology in vehicles, the functions realized by ADAS (Advanced Driver Assistance System) are becoming more and more diverse, and the demand for the performance of vehicle-mounted millimeter-wave radar is also increasing. The main task of vehicle-mounted radar is to detect targets such as motor vehicles, non-motor vehicles and pedestrians in the detection area and estimate the distance, speed and angle information corresponding to the target.

[0003] In order to improve the resolution characteristics of the target in each dimension, a variety of technologies have been applied to the field of automotive radar, such as the use of MIMO (Multiple-Input Multiple-Output) technology to increase the virtual aperture and improve the angular resolution of the target.

[0004] However, there is a risk of missing the target when using a stepped linear frequency modulation continuous signal to improve the distance resolution of the target, and there is a lack of solutions to this technical problem in the relevant technology. Summary of the invention

[0005] Based on this, it is necessary to provide a signal processing method, system, chip, computer-readable storage medium and computer program product that can reduce the risk of target missed detection in response to the above technical problems.

[0006] In a first aspect, the present application provides a signal processing method, comprising:

[0007] Acquire a current frame digital signal determined based on a target reflection echo;

[0008] Determine a first radial distance dimension spectrum corresponding to the current frame digital signal;

[0009] Acquire target state information of the target in the previous frame, and perform phase compensation on the first radial distance dimension spectrum according to the target state information to obtain a second radial distance dimension spectrum;

[0010] Determine a radial relative velocity spectrum based on the second radial distance dimension spectrum, and obtain a final radial distance-radial relative velocity spectrum after incoherent accumulation;

[0011] Target detection is performed on the final radial distance-radial relative speed spectrum to determine a radial distance index value and a radial relative speed index value of the target.

[0012] In one embodiment, performing slow-time linear phase compensation on the first radial distance dimension spectrum according to the target state information to obtain a second radial distance dimension spectrum includes:

[0013] Perform m fast time sampling and n slow time sampling on the current frame signal, determine the absolute time difference corresponding to the center frequencies of two consecutive linear frequency modulation signals, and determine the absolute time difference as a phase compensation coefficient;

[0014] Determine a phase compensation value of the current frame digital signal for the nth slow time sampling according to the radial relative speed information in the target state information and the phase compensation coefficient;

[0015] Slow-time linear phase compensation is performed on the first radial distance dimension spectrum according to the phase compensation value to obtain a second radial distance dimension spectrum.

[0016] In one embodiment, determining the absolute time difference corresponding to the center frequencies of two consecutive linear frequency modulation signals includes:

[0017] Determine a phase information relationship satisfied by the phase information of the current frame digital signal; the phase information relationship includes a phase adjustment item;

[0018] If the phase adjustment item enables the current frame digital signal to maintain a linear state during slow time sampling, determining a target relationship satisfied by the phase adjustment item;

[0019] Determining an absolute time relationship corresponding to a center frequency of an nth linear frequency modulation signal according to the target relationship;

[0020] According to the absolute time relationship, an absolute time difference corresponding to two consecutive center frequencies of the linear frequency modulation signals is determined.

[0021] In one embodiment, determining the first radial distance dimension spectrum corresponding to the current frame digital signal includes:

[0022] A fast time spectrum acquisition is performed on the current frame digital signal to obtain a first radial distance dimension spectrum corresponding to the current frame digital signal.

[0023] In one embodiment, the performing target detection on the final radial distance-radial relative velocity spectrum to determine the radial distance index value and the radial relative velocity index value of the target includes:

[0024] Performing target detection on the final radial distance-radial relative speed spectrum to obtain a radial distance index value and a radial relative speed index value of the target;

[0025] According to the radial distance index value and the radial relative speed index value, the radial distance and the radial relative speed of the current frame digital signal are solved to obtain the radial distance estimation value and the radial relative speed estimation value of the detected target in the current frame digital signal;

[0026] The radial distance estimation value and the radial relative speed estimation value are used to identify the potential radial distance and radial relative speed interval of the target in the next frame, and / or to determine the phase compensation value in the next frame. In a second aspect, the present application also provides a radar system, the radar system comprising a transmitting antenna, a receiving antenna and a signal processing module, wherein:

[0027] The transmitting antenna is used to transmit a stepped linear frequency modulation continuous wave in a radar transmission cycle;

[0028] The receiving antenna is used to receive the target reflected echo of the stepped linear frequency modulation continuous wave;

[0029] The signal processing module is used to obtain a current frame digital signal determined based on a target reflection echo; determine a first radial distance dimension spectrum corresponding to the current frame digital signal; obtain target state information of the target in the previous frame, perform phase compensation on the first radial distance dimension spectrum according to the target state information, and obtain a second radial distance dimension spectrum; determine a radial relative velocity spectrum based on the second radial distance dimension spectrum, perform incoherent accumulation, obtain a final radial distance-radial relative velocity spectrum, perform target detection on the final radial distance-radial relative velocity spectrum, and determine a radial distance index value and a radial relative velocity index value of the target.

[0030] In a third aspect, the present application further provides a chip, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

[0031] Acquire a current frame digital signal determined based on a target reflection echo;

[0032] Determine a first radial distance dimension spectrum corresponding to the current frame digital signal;

[0033] Acquire target state information of the target in the previous frame, and perform phase compensation on the first radial distance dimension spectrum according to the target state information to obtain a second radial distance dimension spectrum;

[0034] A radial relative velocity spectrum is determined based on the second radial distance dimension spectrum, and after incoherent accumulation, a final radial distance-radial relative velocity spectrum is obtained. Target detection is performed on the final radial distance-radial relative velocity spectrum to determine the radial distance index value and radial relative velocity index value of the target.

[0035] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the following steps are implemented:

[0036] Acquire a current frame digital signal determined based on a target reflection echo;

[0037] Determine a first radial distance dimension spectrum corresponding to the current frame digital signal;

[0038] Acquire target state information of the target in the previous frame, and perform phase compensation on the first radial distance dimension spectrum according to the target state information to obtain a second radial distance dimension spectrum;

[0039] A radial relative velocity spectrum is determined based on the second radial distance dimension spectrum, and after incoherent accumulation, a final radial distance-radial relative velocity spectrum is obtained. Target detection is performed on the final radial distance-radial relative velocity spectrum to determine the radial distance index value and radial relative velocity index value of the target.

[0040] In a fifth aspect, the present application further provides a computer program product, including a computer program, which implements the following steps when executed by a processor:

[0041] Acquire a current frame digital signal determined based on a target reflection echo;

[0042] Determine a first radial distance dimension spectrum corresponding to the current frame digital signal;

[0043] Acquire target state information of the target in the previous frame, and perform phase compensation on the first radial distance dimension spectrum according to the target state information to obtain a second radial distance dimension spectrum;

[0044] A radial relative velocity spectrum is determined based on the second radial distance dimension spectrum, and after incoherent accumulation, a final radial distance-radial relative velocity spectrum is obtained. Target detection is performed on the final radial distance-radial relative velocity spectrum to determine the radial distance index value and radial relative velocity index value of the target.

[0045] The above-mentioned signal processing method, system, chip, computer-readable storage medium and computer program product determine the first radial distance dimension spectrum corresponding to the current frame digital signal; obtain the target state information of the target in the previous frame, and phase compensate the first radial distance dimension spectrum according to the target state information to obtain the second radial distance dimension spectrum; determine the radial relative velocity spectrum based on the second radial distance dimension spectrum, and after incoherent accumulation, obtain the final radial distance-radial relative velocity spectrum, perform target detection on the spectrum, and determine the radial distance index value and radial relative velocity index value of the target. This method can perform corresponding phase compensation for different moving targets and phase compensate for the slow-time nonlinear term introduced by the stepped linear frequency modulation continuous signal by combining the target state information of multiple frames, so that slow-time sampling in the radial relative velocity dimension maintains a linear state, thereby reducing the broadening of the main lobe in the radial relative velocity dimension and reducing the risk of missed detection of different targets. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the drawings required for use in the embodiments of the present application or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0047] Figure 1 is an application environment diagram of a signal processing method in an embodiment;

[0048] Figure 2 is a flow chart of a signal processing method in one embodiment;

[0049] Figure 3 A schematic diagram of a flow chart of a slow-time linear phase compensation method in one embodiment;

[0050] Figure 4 is a flow chart of a signal processing method in another embodiment;

[0051] Figure 5 It is a schematic diagram of the spectrum of radial distance dimension-radial relative velocity dimension in one embodiment;

[0052] Figure 6 is a schematic diagram of a spectrum without phase compensation in one embodiment;

[0053] Figure 7 A spectrum diagram showing how spectrum energy before phase compensation varies with radial relative velocity index values ​​in one embodiment;

[0054] Figure 8A spectrum diagram showing the change of the echo energy of the corresponding target with the radial relative velocity index value after compensation in one embodiment;

[0055] Fig. 9 A spectrum diagram showing how the echo energy of a target after phase compensation varies with the radial relative velocity index value in another embodiment;

[0056] Fig.10 is a schematic diagram of a spectrum diagram of a spectrum energy without phase compensation changing with radial relative velocity index values ​​in one embodiment;

[0057] Fig.11 A schematic diagram of a spectrum diagram showing how the spectrum energy of a target 1 after phase compensation varies with the radial relative velocity index value in one embodiment;

[0058] Fig.12 A schematic diagram of a spectrum diagram showing how the spectrum energy of a target 2 after phase compensation varies with the radial relative velocity index value in one embodiment;

[0059] Fig.13 is a structural block diagram of a radar system in one embodiment;

[0060] Fig.14 FIG. 4 is a diagram showing the internal structure of a chip in one embodiment. DETAILED DESCRIPTION

[0061] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0062] The main task of vehicle-mounted radar is to detect targets, such as motor vehicles, non-motor vehicles and pedestrians, in the detection area and estimate the distance, speed and angle information of the targets. In order to improve the resolution characteristics of the targets in various dimensions, a variety of technologies have been applied to the field of vehicle-mounted radar, such as using MIMO technology to increase the virtual aperture to improve the angular resolution of the target, and using a stepped linear frequency modulation continuous waveform to improve the radial distance resolution of the target.

[0063] Although the use of a step-linear frequency modulation continuous signal is beneficial to improving the target's range resolution, the introduction of the step-linear frequency modulation continuous signal causes a nonlinear relationship between the target phase change output by the analog-to-digital converter and the slow-time sampling. This nonlinear relationship will lead to the introduction of a sampling phase error when performing a discrete Fourier transform in the radial relative velocity dimension, and this error will increase with the increase of the radial relative velocity of the moving target. As a result, the main lobe of the target in the radial relative velocity dimension will be widened, and the corresponding peak energy will decrease, which can easily cause the target to be missed.

[0064] However, in the related art, the reason why the use of the step frequency modulation waveform causes the expansion of the speed dimension cannot be located for the missed detection of the target, and the suppression effect only from the waveform level is limited due to the chip configuration accuracy. In addition, it is necessary to target high-speed moving targets. In view of these technical difficulties, there is a lack of a signal processing method in the related art. In order to solve the problem of missed detection of high-speed moving targets caused by the use of step linear frequency modulation continuous signals, a signal processing method is proposed, which determines the first radial distance dimension spectrum corresponding to the current frame digital signal; obtains the target state information of the target in the previous frame, and performs slow time linear phase compensation on the first radial distance dimension spectrum according to the target state information to obtain the second radial distance dimension spectrum; determines the radial relative speed spectrum based on the second radial distance dimension spectrum, and obtains the final radial distance-radial relative speed spectrum after incoherent accumulation, performs target detection on the spectrum, determines the radial distance index value and radial relative speed index value of the target, and reduces the main lobe width of the radial relative speed dimension of the moving target through slow time nonlinear phase compensation, thereby reducing the risk of missed detection of the target. This method considers suppressing the widening of the main lobe of the radial relative speed dimension caused by the use of the step linear frequency modulation signal from the root.

[0065] The signal processing method provided in the embodiment of the present application can be applied to Figure 1 In the application environment shown. A radar system 104 is deployed on the mobile carrier 102. The radar system 104 includes a radar and a signal processing unit. The radar can be but is not limited to different types of vehicle-mounted millimeter-wave radars. The deployment location of the radar can be set according to actual needs. Figure 1 The radar shown in is for illustration only. The mobile carrier 102 may be a vehicle-mounted platform, such as a car, motorcycle or bicycle. Alternatively, the mobile carrier 102 may be a ship-mounted platform, such as a ship, a ship, a motorboat, etc. Alternatively, the mobile carrier 102 may be a vehicle-mounted platform or an airborne platform, such as a drone, a helicopter or a jet, a balloon, etc. When the mobile carrier 102 is a vehicle, the vehicle-mounted millimeter-wave radar may detect objects in the detection area, and the objects in the detection area may be, but are not limited to, high-speed moving targets 1 and high-speed moving targets 2. The data storage system may store data that the mobile carrier 102 needs to process. The data storage system may be integrated on the mobile carrier 102, or may be placed on a cloud server or other network server.

[0066] In an exemplary embodiment, Figure 2 As shown, a signal processing method is provided, which is applied to Figure 1 The application environment in FIG. 1 is taken as an example to illustrate, including the following steps 202 to 208. Among them:

[0067] Step 202: Acquire a current frame digital signal determined based on the target reflection echo.

[0068] It should be noted that the fast time sampling dimension and the slow time sampling dimension may correspond to the radial distance dimension and the radial relative speed dimension. The current frame digital signal may also be called the current frame digital echo signal.

[0069] The stepped linear frequency modulated continuous wave corresponding to the target reflected echo is transmitted by the radar system. The radar system includes K transmitting antennas and L receiving antennas, where K and L are positive integers, and the number of K and L is not limited. The radar system can be a MIMO radar system, in which various multiple access technologies such as time division multiple access (TDMA), frequency division multiple access (FDMA) and Doppler division multiple access (DDMA) can be applied.

[0070] For the convenience of describing the technical solution, in the following detailed description, the radar system includes K = 1 transmitting antenna and L = 1 receiving antenna. The frequency modulation slope of each linear frequency modulation signal is expressed as To represent, each linear frequency modulation signal contains M fast time samples, that is, m=0...M-1, and each waveform transmission cycle contains N linear frequency modulation signals, that is, n=0...N-1. The radar system uses a stepped linear frequency modulation continuous signal to obtain the characteristics of high range resolution of the target. Accordingly, the center frequency difference of two continuous linear frequency modulation signals is expressed as The center frequency is expressed as To express. To represent the absolute time corresponding to the center frequency of the nth linear frequency modulation signal. The target reflected echo is received by the radar receiver, and then passes through the mixer, low-pass filter, amplifier and analog-to-digital converter to obtain the digital signal of the current frame, which is recorded as .

[0071] Step 204: determine a first radial distance dimension spectrum corresponding to the current frame digital signal.

[0072] It is understandable that the confirmation of the target radial distance information depends on the digital processing signal of the current frame. In the confirmation of the corresponding frequency in the fast time, therefore, the fast time spectrum acquisition can be performed on the current frame digital signal to obtain the first radial distance dimension spectrum corresponding to the current frame digital signal. The fast time spectrum acquisition can be but is not limited to the fast time discrete Fourier transform, for example, the fast time discrete Fourier transform (or its corresponding fast algorithm in engineering implementation) and other methods are used to obtain the current frame digital signal The spectrum in the radial distance dimension is denoted by , that is, the spectrum of the first radial distance dimension.

[0073] Step 206 , obtaining target state information of the target in the previous frame, and performing slow-time linear phase compensation on the first radial distance dimension spectrum according to the target state information to obtain a second radial distance dimension spectrum.

[0074] The target state information includes the radial relative velocity estimate and radial distance estimate of the target in the previous frame. It should be noted that the phase compensation is calculated only based on the radial relative velocity estimate, and the radial distance estimate of the target in the previous frame can be used to find the distance information of the target in the previous frame.

[0075] The number of targets in the previous frame can be, but is not limited to, one, and can also be multiple. This embodiment is explained by taking the number of targets in the previous frame as 1. Slow-time linear phase compensation can be understood as phase compensation for the slow-time nonlinear term introduced by the stepped linear frequency modulation continuous signal, so that the slow-time sampling in the radial relative speed dimension maintains a linear state. The implementation method of slow-time linear phase compensation can determine the phase compensation coefficient according to the absolute time difference corresponding to the center frequencies of two consecutive linear frequency modulation signals, determine the corresponding phase compensation value according to the phase compensation coefficient and the radial relative speed information, and then compensate the phase of the corresponding dimension based on the phase compensation value to obtain the compensated second radial distance dimension spectrum.

[0076] Step 208, determine the radial relative velocity spectrum based on the second radial distance dimension spectrum, perform incoherent accumulation to obtain the final radial distance-radial relative velocity spectrum, perform target detection on the final radial distance-radial relative velocity spectrum, and determine the radial distance index value and radial relative velocity index value of the target.

[0077] The radial distance index value and the radial relative speed index value can be used to calculate the radial distance and radial relative speed of the current frame to obtain the radial distance estimation value and radial relative speed estimation value of the target in the current frame. The specific calculation method can be implemented in an existing manner and will not be described in detail here.

[0078] Exemplarily, the radial relative velocity spectrum is determined based on the second radial distance dimension spectrum, and after incoherent accumulation, the final radial distance-radial relative velocity spectrum is obtained, and target detection is performed on the final radial distance-radial relative velocity spectrum. On this basis, the target detection algorithm is used to obtain the radial distance index value and radial relative velocity index value of the target. Furthermore, the radial distance and radial relative velocity of the current frame are solved according to the obtained distance index value and radial relative velocity index value to obtain the radial distance estimation value and radial relative velocity estimation value of the target in the current frame, and the estimation value can be used to determine the phase compensation value of the next frame.

[0079] It should be noted that the method of determining the radial relative velocity spectrum from the radial distance dimension spectrum can be implemented by existing methods, which will not be described in detail here. This method of determining the phase compensation value of the next frame by using the radial relative velocity estimation value of the target in the previous frame combines the target state information of multiple frames, and can perform corresponding phase compensation for different moving targets to reduce the risk of different targets being missed.

[0080] In the above signal processing method, the first radial distance dimension spectrum corresponding to the current frame digital signal is determined; the target state information of the target in the previous frame is obtained, and the first radial distance dimension spectrum is phase compensated according to the target state information to obtain the second radial distance dimension spectrum; the radial relative velocity spectrum is determined based on the second radial distance dimension spectrum, and after incoherent accumulation, the final radial distance-radial relative velocity spectrum is obtained, and the target detection is performed on the final radial distance-radial relative velocity spectrum to determine the radial distance index value and radial relative velocity index value of the target. This method combines the target state information of multiple frames to perform corresponding phase compensation for different moving targets, and performs phase compensation for the slow-time nonlinear term introduced by the stepped linear frequency modulation continuous signal, so that the slow-time sampling in the radial relative velocity dimension maintains a linear state, thereby reducing the broadening of the main lobe in the radial relative velocity dimension and reducing the risk of missed detection of different targets.

[0081] In addition, the above method can be implemented inside the digital signal processing unit of the vehicle-mounted radar chip. This method can further avoid the limitation of the waveform configuration accuracy of the ramp generator in the vehicle-mounted radar chip, that is, it is not limited by the chip waveform configuration conditions.

[0082] Since the target phase change introduced by the step-linear frequency modulation continuous signal has a nonlinear relationship with the slow time sampling, which leads to the broadening of the main lobe of the target in the radial relative velocity dimension, in an exemplary embodiment, Figure 3 As shown, a slow time linear phase compensation method is proposed, including steps 302 to 306. Among them:

[0083] Step 302: Perform m fast time sampling and n slow time sampling on the current frame signal, determine the absolute time difference corresponding to the center frequencies of two consecutive linear frequency modulation signals, and determine the absolute time difference as the phase compensation coefficient.

[0084] The absolute time difference may be determined by controlling the absolute time corresponding to the center frequency so that the slow time sampling remains linear. The current frame signal is determined based on the target reflection echo.

[0085] Optionally, in an exemplary embodiment, a method for determining an absolute time difference is provided, including: determining a phase information relationship satisfied by the phase information of the current frame signal; the phase information relationship includes a phase adjustment item; if the phase adjustment item makes the echo signal, that is, the current frame digital signal, maintain a linear state during slow time sampling, then determining a target relationship satisfied by the phase adjustment item; based on the target relationship, determining the absolute time relationship corresponding to the center frequency of the nth linear frequency modulation signal; based on the absolute time relationship, determining the absolute time difference corresponding to the center frequencies of two consecutive linear frequency modulation signals.

[0086] It can be understood that when phase compensation is not performed, the absolute time difference corresponding to the center frequencies of two consecutive linear frequency modulation signals can be expressed as:

[0087] ;

[0088] Assume that the estimated radial relative velocity of the target to be estimated in the current frame is Estimated radial relative velocity of the target compared to the previous frame There is a deviation, that is ,in Represents the deviation of the radial relative velocity between two consecutive frames. m represents the fast time sampling. Since the next step is to analyze the slow time, it can be directly understood as irrelevant to the fast time analysis.

[0089] Phase information of the current frame digital signal It can be expressed as:

[0090] ;

[0091] in, represents the frequency modulation slope of each linear frequency modulation signal, and the center frequency of slow time sampling is expressed as:

[0092] ;

[0093] The radial distance of the slow-time sampling target is expressed as:

[0094] , is the target radial distance.

[0095] Letting m = 0 will simplify the expression. When m = 0, that is, when m is a preset value, the phase information of the digital signal corresponding to the current frame can be expressed as:

[0096] ;

[0097] For the second term in the above equation, the phase adjustment term , if the echo signal is kept linear during slow time sampling, that is, the following target relationship is satisfied:

[0098] ;

[0099] Under the premise of maintaining the above equation relationship, the absolute time corresponding to the center frequency of the nth linear frequency modulation signal can be obtained, and the absolute time can be expressed as the following relationship:

[0100] ;

[0101] Based on the above absolute time representation relationship, the absolute time difference corresponding to the center frequencies of two consecutive linear frequency modulation signals can be determined. The absolute time difference can be expressed as:

[0102] .

[0103] It should be noted that the absolute time difference is determined as the phase compensation coefficient, and the symbol is used here It is worth noting that when n=0, that is, for the first linear frequency modulation signal, since there is no absolute time difference at this moment, the corresponding phase compensation coefficient is .

[0104] Furthermore, based on the method of determining the phase compensation coefficient, it can be known that the phase compensation coefficient can be obtained through offline calculation before the radar system is operated. The compensation coefficient is calculated in advance and recorded in a table to optimize the time. During the operation of the radar system, the corresponding phase compensation coefficient can be obtained by looking up the table, and the phase compensation value can be further calculated in combination with the historical motion state information of the target, thereby reducing the computational burden of the system during operation.

[0105] Step 304: Determine the phase compensation value of the current frame digital signal for the nth slow time sample according to the radial relative speed information and the phase compensation coefficient in the target state information.

[0106] It can be understood that since the target radial relative velocity estimation value of the current frame is not obtained at this time, the target radial relative velocity estimation value of the previous frame can be used when determining the phase compensation value. The radial relative velocity information includes a radial relative velocity estimation value.

[0107] Exemplarily, the phase compensation value of the current frame digital signal for the nth slow time sampling is determined according to the target radial relative velocity estimation value and the phase compensation coefficient in the target state information. The relationship corresponding to the phase compensation value can be expressed as:

[0108] ,in, is the phase compensation coefficient of the nth linear frequency modulation signal.

[0109] Step 306 , performing slow time linear phase compensation on the first radial distance dimension spectrum according to the phase compensation value to obtain a second radial distance dimension spectrum.

[0110] It can be understood that when performing slow-time linear phase compensation, the corresponding phase in the first radial distance dimension spectrum is compensated according to the phase compensation value of the slow-time sampling of the echo signal.

[0111] For example, in an exemplary embodiment, according to the phase compensation value, the slow time linear phase compensation of the first radial distance dimension spectrum is completed to obtain the second radial distance dimension spectrum. The compensated second radial distance dimension spectrum can be recorded as , as shown below:

[0112] .

[0113] In this embodiment, by performing phase compensation on the slow-time nonlinear term introduced by the stepped linear frequency modulation continuous signal, the slow-time sampling of the echo signal in the radial relative velocity dimension is maintained in a linear state, thereby reducing the broadening of the main lobe in the radial relative velocity dimension and reducing the risk of missed target detection.

[0114] It can be understood that, by combining target state information of multiple frames, corresponding phase compensation can be performed for different moving targets to reduce the risk of missing detection of different targets.

[0115] Therefore, in an exemplary embodiment, target detection is performed on the final radial distance-radial relative velocity spectrum to determine the radial distance index value and radial relative velocity index value of the target, including: performing target detection on the final radial distance-radial relative velocity spectrum to obtain the radial distance index value and radial relative velocity index value of the target; according to the radial distance index value and the radial relative velocity index value, the radial distance and radial relative velocity of the current frame digital signal are resolved to obtain the radial distance estimation value and radial relative velocity estimation value of the detected target in the current frame digital signal; wherein the radial distance estimation value and the radial relative velocity estimation value are used to identify the potential radial distance and radial relative velocity intervals of the target in the next frame, and / or, to determine the phase compensation value of the next frame.

[0116] Among them, the target detection and solution method can be implemented by existing methods, which will not be described in detail here. Further, additional window functions, such as Hanning window, Hamming window, etc., can be used, which can be applied to the radial distance dimension and the radial relative velocity dimension respectively to jointly suppress the side lobes. The selection and application of the window function are not limited in this application.

[0117] In an exemplary embodiment, Figure 4As shown, a signal processing method is provided, which is applied to Figure 1 The application environment in the embodiment is described by taking the internal processing of the digital signal processing unit of the vehicle-mounted radar chip as an example, including the following steps 402 to 414. Among them:

[0118] Step 402 : Perform m fast-time sampling and n slow-time sampling on the current frame signal to obtain a current frame digital signal determined based on the target reflection echo.

[0119] Step 404: determine a first radial distance dimension spectrum corresponding to the current frame digital signal.

[0120] Step 406: determine the absolute time difference corresponding to the center frequencies of two consecutive linear frequency modulation signals, and determine the absolute time difference as a phase compensation coefficient.

[0121] Step 408: Determine the phase compensation value of the current frame digital signal for the nth slow time sample according to the radial relative speed information and the phase compensation coefficient in the target state information.

[0122] Step 410 , performing slow-time linear phase compensation on the first radial distance dimension spectrum according to the phase compensation value to obtain a second radial distance dimension spectrum.

[0123] Step 412, determine the radial relative velocity spectrum based on the second radial distance dimension spectrum, perform incoherent accumulation to obtain the final radial distance-radial relative velocity spectrum, perform target detection on the final radial distance-radial relative velocity spectrum, and determine the radial distance index value and radial relative velocity index value of the target.

[0124] Step 414 , calculate the radial distance and radial relative speed of the current frame digital signal according to the radial distance index value and the radial relative speed index value, obtain the radial distance estimation value and radial relative speed estimation value of the detected target in the current frame digital signal, and execute step 406 .

[0125] It should be noted that the radial distance estimation value and radial relative speed estimation value of the detected target obtained in the current frame digital signal can be used to determine the phase compensation value of the next frame until the signal processing is completed.

[0126] It can be understood that the implementation method in this embodiment can be implemented in the manner defined in the above embodiment, which will not be elaborated here.

[0127] In this embodiment, by combining the target state of multiple frames and performing phase compensation on the slow-time nonlinear term introduced by the step-linear frequency modulation continuous signal in the digital signal processing unit, the linear state is maintained by slow-time sampling in the radial relative velocity dimension, thereby reducing the broadening of the main lobe in the radial relative velocity dimension and reducing the risk of missed target detection. In addition, by applying it to the digital signal processing unit of the vehicle-mounted radar chip, the limitation of the waveform configuration accuracy of the ramp generator in the vehicle-mounted radar chip is avoided.

[0128] The following are application scenarios of the above signal processing method:

[0129] Scenario 1: Single moving target, and the speed of the moving target in two consecutive frames is similar

[0130] The frequency modulation slope of each linear frequency modulation signal of the radar system is , each linear frequency modulation signal contains M = 128 fast time samples, that is, m = 0 ... 127. Each waveform transmission cycle contains N = 256 linear frequency modulation signals, that is, n = 0 ... 255. The center frequency is The center frequency difference between two consecutive linear frequency modulation signals is There is a single moving target in the environment, and the radar receiver obtains the digital signal of the current frame of the target. , for the digital signal of the current frame Fast time spectrum acquisition is performed. In this embodiment, the fast Fourier transform algorithm is used to implement discrete Fourier transform to obtain the spectrum of the radial distance dimension of the digital signal, and it is recorded as .

[0131] According to the estimated radial relative velocity of the target in the previous frame, phase compensation is performed on the target in the current frame. The phase compensation of the target in the current frame specifically includes the following steps:

[0132] Get the estimated radial distance of the target in the previous frame and the target radial relative velocity estimate .

[0133] When phase compensation is not performed, the absolute time difference between the center frequencies of two consecutive linear frequency modulation signals is In this embodiment, it is assumed that the relative radial velocity of the target remains approximately the same for two consecutive frames. ,Right now, When m=0, the phase information corresponding to the current frame digital signal is:

[0134] ;

[0135] in, ;

[0136] For the second term on the right hand side of the phase information equation, the echo signal is kept linear during slow time sampling, that is,

[0137] ;

[0138] Under the premise of maintaining the above equation relationship, the absolute time corresponding to the center frequency of the nth linear frequency modulation signal can be obtained:

[0139] ;

[0140] According to the above formula, the absolute time difference between the center frequencies of two consecutive linear frequency modulation signals can be obtained as:

[0141] .

[0142] It is worth noting that when n=0, that is, for the first linear frequency modulation signal, since there is no absolute time difference at this moment, the corresponding phase compensation coefficient is .

[0143] Determine the phase compensation value of the current frame digital echo signal for the nth slow time sampling:

[0144] ;

[0145] According to the radial distance dimension spectrum and phase compensation value, the compensated spectrum is obtained, and the compensated spectrum is recorded as , as shown below:

[0146] ;

[0147] Radial distance dimension spectrum after phase compensation In this embodiment, the fast Fourier transform algorithm is used to implement the discrete Fourier transform to obtain the spectrum of the radial relative velocity dimension, which is recorded as After incoherent accumulation, the final radial distance-radial relative velocity spectrum is obtained. The corresponding spectrum is as follows: Figure 5 To demonstrate the effect of this application, Figure 6 is the spectrum without phase compensation. By comparison, it can be found that the method provided by the present application can effectively suppress the broadening of the main lobe in the radial relative velocity dimension and improve the problem of missed target detection. In addition, Figure 7 and Figure 8 The spectrum of the spectral energy of the corresponding target before and after phase compensation changes with the radial relative velocity index value. The application of the phase compensation method of this application can significantly suppress the main lobe broadening of the target radial relative velocity dimension, and the corresponding target energy is stronger than the uncompensated method, so this solution can reduce the risk of missed detection of the target.

[0148] The target detection algorithm is used to obtain the radial distance index value and radial relative speed index value of the target on the final radial distance-radial relative speed spectrum. Common target detection algorithms can use CA-CFAR, OS-CFAR, etc. and combine the strategy of local peak selection to determine the final radial distance index value and radial relative speed index value of the target. This patent does not make any unnecessary principle elaboration and restrictions on this. The radial distance and radial relative speed of the current frame are solved by the obtained radial distance index value and radial relative speed index value to obtain the radial distance estimate value and radial relative speed estimate value of the target in the current frame, which are recorded as The estimated value can be used to identify the potential radial distance and radial relative velocity interval of the target in the next frame, and to determine the phase compensation value in the next frame.

[0149] Scenario 2: Single moving target, and the target has an accelerating motion trend in two consecutive frames

[0150] The frequency modulation slope of each linear frequency modulation signal of the radar system is , each linear frequency modulation signal contains M = 128 fast time samples, that is, m = 0 ... 127. Each waveform transmission cycle contains N = 256 linear frequency modulation signals, that is, n = 0 ... 255. The center frequency is , the center frequency difference of two consecutive linear frequency modulation signals is expressed as There is a single moving target in the environment, and the radar receiver obtains the digital signal of the current frame of the target. .

[0151] The digital signal of the current frame Fast time spectrum acquisition is performed. In this embodiment, the fast Fourier transform algorithm is used to implement discrete Fourier transform to obtain the spectrum of the radial distance dimension of the digital signal, and it is recorded as .

[0152] According to the estimated radial relative velocity of the target in the previous frame, phase compensation is performed on the target in the current frame. The phase compensation of the target in the current frame specifically includes the following steps:

[0153] Get the estimated radial distance of the target in the previous frame and the target radial relative velocity estimate .

[0154] When phase compensation is not performed, the absolute time difference between the center frequencies of two consecutive linear frequency modulation signals is In this embodiment, it is assumed that for two consecutive frames, the target has an accelerating motion trend in the radial relative velocity dimension, and the target acceleration is a=13m / s 2 Considering the frame period is 60 ms , corresponding to the radial relative velocity change is Note that the relative radial velocity obtained in the previous frame is still used to confirm the compensation coefficient and phase compensation value. When m=0, the phase information of the digital signal corresponding to the current frame is:

[0155] ;

[0156] in, ;

[0157] For the second term on the right hand side of the above phase information equation, the echo signal is kept linear during slow time sampling, that is,

[0158] ;

[0159] Under the premise of maintaining the above equation relationship, the absolute time corresponding to the center frequency of the nth linear frequency modulation signal can be obtained:

[0160] ;

[0161] According to the above formula, the absolute time difference between the center frequencies of two consecutive linear frequency modulation signals can be obtained as:

[0162] ;

[0163] It is worth noting that when n=0, that is, for the first linear frequency modulation signal, since there is no absolute time difference at this moment, the corresponding phase compensation coefficient is .

[0164] Determine the phase compensation value of the current frame digital echo signal for the nth slow time sampling:

[0165] ;

[0166] According to the radial distance dimension spectrum and phase compensation value, the compensated spectrum is obtained, and the compensated spectrum is recorded as , as shown below:

[0167] .

[0168] Radial distance dimension spectrum after phase compensation In this embodiment, the fast Fourier transform algorithm is used to implement the discrete Fourier transform to obtain the spectrum of the radial relative velocity dimension, which is recorded as , after incoherent accumulation, the final radial distance-radial relative velocity spectrum is obtained. Fig. 9It can be seen that in one embodiment, the spectrum of the echo energy of the target after phase compensation changes with the radial relative velocity index value. Even if the estimated value of the radial relative velocity deviation in the previous frame is used when determining the phase compensation value of the current frame, the method proposed in the present application effectively suppresses the main lobe broadening in the radial relative velocity dimension on the basis of sacrificing a small amount of target spectrum energy, thereby reducing the risk of target missed detection.

[0169] The target detection algorithm is used to obtain the radial distance index value and radial relative speed index value of the target on the final radial distance-radial relative speed spectrum. Common target detection algorithms can use CA-CFAR, OS-CFAR, etc. and combine the strategy of local peak selection to determine the final radial distance index value and radial relative speed index value of the target. This patent does not make any unnecessary principle elaboration and restrictions on this. The radial distance and radial relative speed of the current frame are solved by the obtained radial distance index value and radial relative speed index value to obtain the radial distance estimate value and radial relative speed estimate value of the target in the current frame, which are recorded as The estimated value can be used to identify the potential radial distance and radial relative velocity interval of the target in the next frame, and to determine the phase compensation value in the next frame.

[0170] Scenario 3: Two moving targets, and the speeds of the moving targets in two consecutive frames are similar

[0171] The frequency modulation slope of each linear frequency modulation signal of the radar system is , each linear frequency modulation signal contains M = 128 fast time samples, that is, m = 0 ... 127. Each waveform transmission cycle contains N = 256 linear frequency modulation signals, that is, n = 0 ... 255. The center frequency is , the center frequency difference of two consecutive linear frequency modulation signals is expressed as There are two targets moving at high speed in the environment, and the radar receiver obtains the digital signal of the current frame of the target. .

[0172] The digital signal of the current frame Fast time spectrum acquisition is performed. In this embodiment, the fast Fourier transform algorithm is used to implement discrete Fourier transform to obtain the spectrum of the echo signal distance dimension and recorded as .

[0173] According to the estimated radial relative velocity of the target in the previous frame, phase compensation is performed on the target in the current frame. The phase compensation of the target in the current frame specifically includes the following steps:

[0174] Get the estimated radial distance of target 1 in the previous frame and the estimated radial relative velocity of target 1 , and the estimated radial distance of target 2 in the previous frame and the estimated radial relative velocity of target 2 .

[0175] When phase compensation is not performed, the absolute time difference between the center frequencies of two consecutive linear frequency modulation signals is T=65μs. In this embodiment, it is assumed that the relative radial velocities of the two targets remain similar for two consecutive frames. When m=0, the phase information of the digital signal corresponding to target 1 in the current frame is

[0176]

[0177] And the phase information of the digital signal of the current frame target 2 is

[0178] ;

[0179] in, ;

[0180] For the second term on the right hand side of the two equations above, the echo signal is kept linear during slow time sampling.

[0181] ;

[0182] Target 2

[0183] ;

[0184] Under the premise of maintaining the above two equations for target 1 and target 2, the absolute time corresponding to the center frequency of the nth linear frequency modulation signal can be obtained:

[0185] ;

[0186] According to the above formula, the absolute time difference corresponding to the center frequencies of two consecutive linear frequency modulation signals can be obtained. This time difference is consistent for two targets, that is,

[0187]

[0188] It is worth noting that when n=0, that is, for the first linear frequency modulation signal, since there is no absolute time difference at this moment, the corresponding phase compensation coefficient is .

[0189] Determine the phase compensation value of the nth slow time sampling of the current frame digital signal echo to target 1:

[0190] And determine the phase compensation value of the nth slow time sampling of the current frame digital signal echo to the target 2:

[0191]

[0192] According to the radial distance dimension spectrum and phase compensation value, the compensated spectrum is obtained, and phase compensation operations are performed on different targets respectively. The compensated spectrum is recorded as and ,Right now

[0193] Target 1

[0194]

[0195] Target 2

[0196]

[0197] Radial distance dimension spectrum after phase compensation for different targets and In this embodiment, the fast Fourier transform algorithm is used to implement the discrete Fourier transform to obtain the spectrum of the radial relative velocity dimension, which is recorded as and , after incoherent accumulation, the final radial distance-radial relative velocity spectrum is obtained. Fig.10 This is a spectrum diagram showing the change of spectral energy with radial relative velocity index value corresponding to the phase compensation method proposed in this application not being applied. Fig.11 The spectrum diagram of the spectrum energy corresponding to the phase compensation scheme proposed in this application for target 1 as the radial relative velocity index value changes, Fig.12 This is a spectrum diagram of the spectrum energy corresponding to the phase compensation solution proposed in this application for target 2 as the radial relative velocity index value changes. Fig.10 and Fig.11 ,as well as Fig.10 and Fig.12 , which can clearly verify the effectiveness of the present application in suppressing the main lobe broadening in the radial relative velocity dimension.

[0198] For each final radial distance-radial relative velocity spectrum, a target detection algorithm is used to obtain the target's radial distance index value and radial relative velocity index value. Common target detection algorithms can use CA-CFAR, OS-CFAR, etc. and combine local peak selection strategies to determine the target's final radial distance index value and radial relative velocity index value. This patent does not make any unnecessary elaboration or restrictions on this. The distance and speed of the current frame are solved using the obtained radial distance index value and radial relative velocity index value to obtain the radial distance estimate and radial relative velocity estimate of the target in the current frame, recorded as The estimated value can be used to identify the potential radial distance and radial velocity interval of the target in the next frame, and to determine the phase compensation value in the next frame.

[0199] It should be understood that, although the steps in the flowcharts involved in the above embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps is not strictly limited in order, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above embodiments may include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0200] Based on the same inventive concept, the embodiment of the present application also provides a radar system for implementing the signal processing method involved above. The implementation scheme for solving the problem provided by the system is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more radar system embodiments provided below can refer to the limitations on the signal processing method above, and will not be repeated here.

[0201] In an exemplary embodiment, Fig.13 As shown, a radar system is provided, the radar system includes a transmitting antenna, a receiving antenna and a signal processing module, wherein:

[0202] The transmitting antenna is used to transmit a stepped linear frequency modulated continuous wave in a radar transmission cycle;

[0203] The receiving antenna is used for receiving the target reflected echo of the stepped linear frequency modulation continuous wave;

[0204] The signal processing module is used to obtain a current frame digital signal determined based on a target reflection echo; determine a first radial distance dimension spectrum corresponding to the current frame digital signal; obtain target state information of the target in the previous frame, perform phase compensation on the first radial distance dimension spectrum according to the target state information, and obtain a second radial distance dimension spectrum; determine a radial relative velocity spectrum based on the second radial distance dimension spectrum, perform incoherent accumulation, obtain a final radial distance-radial relative velocity spectrum, perform target detection on the spectrum, and determine a radial distance index value and a radial relative velocity index value of the target.

[0205] The above-mentioned radar system determines the first radial distance dimension spectrum corresponding to the current frame digital signal; obtains the target state information of the target in the previous frame, and performs phase compensation on the first radial distance dimension spectrum according to the target state information to obtain the second radial distance dimension spectrum; determines the radial relative velocity spectrum based on the second radial distance dimension spectrum, and obtains the final radial distance-radial relative velocity spectrum after incoherent accumulation, performs target detection on the spectrum, and determines the radial distance index value and radial relative velocity index value of the target. This method can perform corresponding phase compensation for different moving targets and phase compensate for the slow-time nonlinear term introduced by the stepped linear frequency modulation continuous signal by combining the target state information of multiple frames, so that the slow-time sampling in the radial relative velocity dimension maintains a linear state, thereby reducing the broadening of the main lobe in the radial relative velocity dimension and reducing the risk of missed detection of different targets.

[0206] Optionally, in an exemplary embodiment, the signal processing module is further used to perform m fast time sampling and n slow time sampling on the current frame signal, determine the absolute time difference corresponding to the center frequencies of two consecutive linear frequency modulation signals, and determine the absolute time difference as the phase compensation coefficient;

[0207] Determine the phase compensation value of the current frame digital signal for the nth slow time sampling according to the radial relative speed information and the phase compensation coefficient in the target state information;

[0208] Slow time linear phase compensation is performed on the first radial distance dimension spectrum according to the phase compensation value to obtain a second radial distance dimension spectrum.

[0209] Optionally, in an exemplary embodiment, the signal processing module is further used to determine a phase information relationship satisfied by the phase information when m in the phase information is a preset value; the phase information relationship includes a phase adjustment item;

[0210] If the phase adjustment item makes the current frame digital signal maintain a linear state when the digital signal is sampled at a slow time, then determining the target relationship satisfied by the phase adjustment item;

[0211] Determining an absolute time relationship corresponding to a center frequency of an nth linear frequency modulation signal according to a target relationship;

[0212] According to the absolute time relationship, the absolute time difference corresponding to the center frequencies of two consecutive linear frequency modulation signals is determined.

[0213] Optionally, in an exemplary embodiment, the signal processing module is further used to perform fast time spectrum acquisition on the current frame digital signal to obtain a first radial distance dimension spectrum corresponding to the current frame digital signal.

[0214] Optionally, in an exemplary embodiment, the signal processing module is further used to perform target detection on the final radial distance-radial relative speed spectrum to obtain a radial distance index value and a radial relative speed index value of the target;

[0215] According to the radial distance index value and the radial relative speed index value, the radial distance and the radial relative speed of the current frame digital signal are solved to obtain the radial distance estimation value and the radial relative speed estimation value of the detected target in the current frame digital signal;

[0216] The radial distance estimation value and the radial relative speed estimation value are used to identify the potential radial distance and radial relative speed interval of the target in the next frame, and / or to determine the phase compensation value in the next frame.

[0217] Each module in the above radar system can be implemented in whole or in part by software, hardware or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute operations corresponding to each module.

[0218] In an exemplary embodiment, a chip is provided, such as Fig.14 As shown, the chip includes a processor and a memory, the processor may be a central processing unit, a specific ASIC, or one or more integrated circuits for controlling program execution, and the memory includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. When the computer program is executed by the processor, a signal processing method is implemented.

[0219] Those skilled in the art will understand that Fig.14 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0220] In one embodiment, a chip is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

[0221] In one embodiment, a computer device is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above method embodiments when executing the computer program.

[0222] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0223] In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by a processor.

[0224] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0225] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic unit, a data processing logic unit based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0226] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0227] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A signal processing method, characterized in that: The method comprises: Acquire a current frame digital signal based on the target reflection echo; Determine a first radial distance dimension spectrum corresponding to the current frame digital signal; Acquire target state information of the target in the previous frame, and perform slow-time linear phase compensation on the first radial distance dimension spectrum according to the target state information to obtain a second radial distance dimension spectrum; Determine a radial relative velocity spectrum based on the second radial distance dimension spectrum, perform incoherent accumulation to obtain a final radial distance-radial relative velocity spectrum, perform target detection on the final radial distance-radial relative velocity spectrum, and determine a radial distance index value and a radial relative velocity index value of the target; The step of performing slow-time linear phase compensation on the first radial distance dimension spectrum according to the target state information to obtain a second radial distance dimension spectrum includes: Perform m fast time sampling and n slow time sampling on the current frame signal, determine the absolute time difference corresponding to the center frequencies of two consecutive linear frequency modulation signals, and determine the absolute time difference as a phase compensation coefficient; Determine a phase compensation value of the current frame digital signal for the nth slow time sampling according to the radial relative speed information in the target state information and the phase compensation coefficient; Slow-time linear phase compensation is performed on the first radial distance dimension spectrum according to the phase compensation value to obtain a second radial distance dimension spectrum.

2. The method according to claim 1, characterized in that The step of determining the absolute time difference corresponding to the center frequencies of two consecutive linear frequency modulation signals includes: Determine a phase information relationship satisfied by the phase information of the current frame digital signal; the phase information relationship includes a phase adjustment item; If the phase adjustment item enables the current frame digital signal to maintain a linear state during slow time sampling, determining a target relationship satisfied by the phase adjustment item; Determining an absolute time relationship corresponding to a center frequency of an nth linear frequency modulation signal according to the target relationship; According to the absolute time relationship, an absolute time difference corresponding to two consecutive center frequencies of the linear frequency modulation signals is determined.

3. The method according to claim 1, characterized in that The determining of a first radial distance dimension spectrum corresponding to the current frame digital signal comprises: A fast time spectrum acquisition is performed on the current frame digital signal to obtain a first radial distance dimension spectrum corresponding to the current frame digital signal.

4. The method according to any one of claims 1 to 3, characterized in that: The performing target detection on the final radial distance-radial relative speed spectrum to determine the radial distance index value and the radial relative speed index value of the target includes: Performing target detection on the final radial distance-radial relative speed spectrum to obtain a radial distance index value and a radial relative speed index value of the target; According to the radial distance index value and the radial relative speed index value, the radial distance and the radial relative speed of the current frame digital signal are solved to obtain the radial distance estimation value and the radial relative speed estimation value of the detected target in the current frame digital signal; The radial distance estimation value and the radial relative speed estimation value are used to identify the potential radial distance and radial relative speed interval of the target in the next frame, and / or to determine the phase compensation value in the next frame.

5. A radar system, characterized in that: The radar system includes a transmitting antenna, a receiving antenna and a signal processing module, wherein: The transmitting antenna is used to transmit a stepped linear frequency modulation continuous wave in a radar transmission cycle; The receiving antenna is used to receive the target reflected echo of the stepped linear frequency modulation continuous wave; The signal processing module is used to obtain a current frame digital signal determined based on the target reflection echo; determine a first radial distance dimension spectrum corresponding to the current frame digital signal; obtain target state information of the previous frame target, and perform phase compensation on the first radial distance dimension spectrum according to the target state information to obtain a second radial distance dimension spectrum; Determine a radial relative velocity spectrum based on the second radial distance dimension spectrum, and obtain a final radial distance-radial relative velocity spectrum after incoherent accumulation; Performing target detection on the final radial distance-radial relative speed spectrum to determine the radial distance index value and radial relative speed index value of the target; the signal processing module is also used to perform m fast time sampling and n slow time sampling on the current frame signal to determine the absolute time difference corresponding to the center frequencies of two consecutive linear frequency modulation signals, and determine the absolute time difference as the phase compensation coefficient; Determine a phase compensation value of the current frame digital signal for the nth slow time sampling according to the radial relative speed information in the target state information and the phase compensation coefficient; Slow-time linear phase compensation is performed on the first radial distance dimension spectrum according to the phase compensation value to obtain a second radial distance dimension spectrum.

6. The system according to claim 5, characterized in that The signal processing module is further used to determine a phase information relationship satisfied by the phase information of the current frame digital signal; the phase information relationship includes a phase adjustment item; If the phase adjustment item enables the current frame digital signal to maintain a linear state during slow time sampling, determining a target relationship satisfied by the phase adjustment item; Determining an absolute time relationship corresponding to a center frequency of an nth linear frequency modulation signal according to the target relationship; According to the absolute time relationship, an absolute time difference corresponding to two consecutive center frequencies of the linear frequency modulation signals is determined.

7. The system according to claim 5, characterized in that The signal processing module is further used to perform fast time spectrum acquisition on the current frame digital signal to obtain a first radial distance dimension spectrum corresponding to the current frame digital signal.

8. A chip comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 4 are implemented.

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

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 4 are implemented.

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