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

Abstract

The present application provides a radar signal processing method and device, radar, and storage medium. The method includes: after generating a high-frequency linear frequency modulation signal, obtaining a preset number of equal parts and a preset phase shift amount; dividing the high-frequency linear frequency modulation signal into time slots based on the number of equal parts, and phase-shifting the high-frequency linear frequency modulation signal after the time slot division based on the phase shift amount; transmitting the phase-shifted high-frequency linear frequency modulation signal and receiving a corresponding echo signal; and performing time slot division and phase compensation on the corresponding echo signal based on the phase shift amount to obtain a target echo signal. By processing radar signals, the present application can reduce interference between radars at a low cost.

Description

Technical Field

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

[0002] In automotive active driving safety technology, millimeter-wave radar, thanks to its 24 / 7, all-weather operation, is becoming an indispensable sensor. With increasing installation volumes, cross-interference between multiple radars has become a serious obstacle to the future development of automotive radar technology. In response to this situation, many research institutions at home and abroad have conducted specialized research and achieved some promising results. For example, V2X (Vehicle-to-Everything) wireless communication technology is being used to share the operating frequencies of multiple radars in a nearby area. Optimization theory is used to adaptively switch the operating frequencies between these radars to minimize cross-interference. This represents a proactive and effective approach to interference mitigation. However, V2X development is currently immature, and conventional millimeter-wave radars are not suitable for V2X technology. The development of V2X and the implementation of V2X in-vehicle terminal products require significant investment. Therefore, a relatively low-cost interference mitigation technology is urgently needed. Summary of the Invention

[0003] The embodiments of the present application provide a radar signal processing method and device, a radar, and a storage medium to solve the problem of relatively high cost of anti-interference technology in the prior art.

[0004] In a first aspect, an embodiment of the present application provides a radar signal processing method, including:

[0005] After generating the high-frequency linear frequency modulation signal, obtaining a preset number of equal parts and a preset phase shift amount;

[0006] Dividing the high-frequency linear frequency modulation signal into time slots based on the number of equal parts, and performing phase shifting on the high-frequency linear frequency modulation signal after the time slot division based on the phase shift amount;

[0007] Transmitting a phase-shifted high-frequency linear frequency modulation signal and receiving the corresponding echo signal;

[0008] The corresponding echo signal is time-slot divided and phase compensated based on the phase shift amount to obtain a target echo signal.

[0009] In a possible implementation manner, before performing phase compensation on the corresponding echo signal based on the phase shift amount, the method further includes:

[0010] Obtaining a maximum delay time between a radar transmit signal and a radar receive signal; wherein the radar transmit signal is a phase-shifted high-frequency linear frequency modulation signal, and the radar receive signal is a corresponding echo signal;

[0011] Determine whether the maximum delay time is less than Wherein, T0 is the time slot after the time slot division, and M is a preset value and is greater than 1;

[0012] If the maximum delay time is not less than Then, envelope alignment is performed on the echo signal.

[0013] In a possible implementation, performing envelope alignment on the echo signal includes:

[0014] performing envelope alignment on the echo signal through a group delay filter;

[0015] The group delay function satisfied by the group delay filter is:

[0016]

[0017] Among them, τ g (f) is the group delay function, T is the time width of the high-frequency linear frequency modulation signal, B is the frequency band of the high-frequency linear frequency modulation signal, f max is the maximum frequency of the radar received signal, and f is the frequency of the sinusoidal signal generated by mixing the radar received signal and the local oscillator signal corresponding to the target at distance r.

[0018] In a possible implementation manner, before performing phase compensation on the corresponding echo signal based on the phase shift amount, the method further includes:

[0019] Determining whether the number of equal parts is greater than a preset threshold;

[0020] If the number of equal parts is greater than the preset threshold, envelope alignment is performed on the echo signal.

[0021] In a possible implementation, the method for determining the phase shift amount includes:

[0022] Generate an N-bit code sequence according to a preset code format, where N is the number of equal parts;

[0023] The phase shift amount of the high frequency linear frequency modulation signal in each time slot is determined according to the coding of each bit of the N-bit coding sequence.

[0024] In a possible implementation, the time slots after the time slot division are: Wherein, T0 is the time slot after the time slot division, T is the time width of the high-frequency linear frequency modulation signal, and N is the number of equal parts.

[0025] In a possible implementation, each time slot corresponds to a phase shift amount, and the phase shifting of the high-frequency linear frequency modulation signal after the time slot division based on the phase shift amount includes:

[0026] The high-frequency linear frequency modulation signal of each time slot is phase-shifted based on the phase shift amount corresponding to each time slot.

[0027] In a second aspect, an embodiment of the present application provides a radar signal processing device, including:

[0028] A data acquisition module, configured to acquire a preset number of equal parts and a preset phase shift amount after generating a high-frequency linear frequency modulation signal;

[0029] a first signal processing module, configured to divide the high-frequency linear frequency modulation signal into time slots based on the number of equal divisions, and perform phase shifting on the high-frequency linear frequency modulation signal after the time slot division based on the phase shift amount;

[0030] The signal transceiver module is used to transmit the phase-shifted high-frequency linear frequency modulation signal and receive the corresponding echo signal;

[0031] The second signal processing module is configured to perform time slot division and phase compensation on the corresponding echo signal based on the phase shift amount to obtain a target echo signal.

[0032] In a third aspect, an embodiment of the present application provides a radar, comprising a processing terminal, the processing terminal comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the method described in the first aspect or any possible implementation of the first aspect are implemented.

[0033] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the steps of the method described in the first aspect or any possible implementation of the first aspect.

[0034] The radar signal processing method and device, radar, and storage medium provided by the embodiments of the present application have the following beneficial effects:

[0035] In an embodiment of the present application, unlike the solution of avoiding radar cross-interference through V2X technology, the embodiment of the present application divides the high-frequency linear frequency modulation signal into time slots by dividing it into equal parts, and shifts the phase of the high-frequency linear frequency modulation signal in each time slot by the phase shift amount, which is equivalent to performing a certain personalized encoding on the high-frequency linear frequency modulation signal to be transmitted, thereby effectively increasing the signal distinction between this radar and other radars in the adjacent area. On this basis, after obtaining the corresponding echo signal, it is only necessary to phase compensate the corresponding echo signal according to the phase shift amount (that is, decode the corresponding echo signal) to obtain an undistorted target echo signal exclusive to the local radar. Among them, the aforementioned encoding can be implemented by the existing phase shifter in the radar, and the aforementioned decoding can be implemented by the existing signal processing circuit in the radar. That is to say, the present application does not require additional equipment or the use of optimization theory to adaptively switch the effective operating frequency points for multiple radars to avoid cross-interference between radars, and the cost is low, thereby effectively solving the problems of the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. 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 any creative work.

[0037] Figure 1 1 is a flow chart of a radar signal processing method provided in an embodiment of the present application;

[0038] Figure 2 Schematic diagram of the structure of the FMCW radar system provided in an embodiment of the present application;

[0039] Figure 3 This is a schematic diagram of the relationship between the FMCW radar echo signal and the target distance provided by an embodiment of the present application;

[0040] Figure 4 This is a schematic diagram of long-coded phase shift provided by an embodiment of the present application;

[0041] Figure 5 is a schematic diagram of an echo signal before envelope alignment provided in an embodiment of the present application;

[0042] Figure 6 is a schematic diagram of an echo signal after envelope alignment provided in an embodiment of the present application;

[0043] Figure 7 This is a schematic diagram of determining the phase shift amount provided in an embodiment of the present application;

[0044] Figure 8is a schematic diagram of a target echo signal after phase compensation provided by an embodiment of the present application;

[0045] Figure 9 1 is a schematic structural diagram of a radar signal processing device provided in an embodiment of the present application;

[0046] Figure 10 Schematic diagram of a radar processing terminal according to an embodiment of the present application. DETAILED DESCRIPTION

[0047] In the following description, specific details such as specific system structures and techniques are provided for purposes of illustration rather than limitation to facilitate a thorough understanding of the embodiments of the present application. However, it will be apparent to those skilled in the art that the present application may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid obscuring the description of the present application with unnecessary detail.

[0048] In order to make the purpose, technical solutions and advantages of this application clearer, specific embodiments will be described below with reference to the accompanying drawings.

[0049] Figure 1 Schematic diagram of the flow of the radar signal processing method provided in the embodiment of the present application. Figure 1 As shown, the method includes:

[0050] S101: After generating a high-frequency linear frequency modulation signal, obtaining a preset number of equal parts and a preset phase shift amount.

[0051] In this embodiment, a high-frequency linear frequency modulation signal is emitted by a transmitter. The number of equal segments is pre-set and can be modified by the user as needed. For example, in a densely populated driving environment with vehicles or pedestrians, the user can increase the number of equal segments to improve the radar's anti-interference performance. After the number of equal segments is pre-set, a code sequence is obtained based on a preset encoding format, and the phase shift amount is determined based on the code sequence. The number of bits in the code sequence is equal to the number of equal segments.

[0052] S102: Divide the high-frequency linear frequency modulation signal into time slots based on the number of equal parts, and perform phase shifting on the high-frequency linear frequency modulation signal divided into time slots based on the phase shift amount.

[0053] In this field, the dimension corresponding to each pulse in the radar signal is usually called the fast time dimension. The time slot division in this embodiment is equivalent to dividing the high-frequency linear frequency modulation signal into N (equal parts). In the fast time dimension, the high-frequency linear frequency modulation signal after the time slot division is phase shifted based on the phase shift amount. The phase shift amount is less than the amount of change in the phase of the high-frequency linear frequency modulation signal within the time slot range. S102 can be implemented by a phase shifter. In this field, the phase shifter is usually used for phased array beam scanning. However, in this embodiment, the phase shifter is innovatively used to encode the high-frequency linear frequency modulation signal (encoding includes time slot division and phase shifting in S102). Based on the solution in the embodiment of the present application, there is no need to add additional encoding devices, which can effectively reduce costs.

[0054] S103: Transmitting the phase-shifted high-frequency linear frequency modulation signal and receiving the corresponding echo signal.

[0055] In this embodiment, the transmitting end transmits a phase-shifted high-frequency linear frequency modulation signal, and the receiving end receives a corresponding echo signal.

[0056] S104: performing time slot division and phase compensation on the corresponding echo signal based on the phase shift amount to obtain a target echo signal.

[0057] In this embodiment, first, the corresponding echo signal is divided into time slots based on the number of equal parts corresponding to the phase shift amount, and then, the corresponding echo signal is phase compensated based on the phase shift amount corresponding to each time slot. The present application takes into account that since the high-frequency linear frequency modulation signal is phase shifted in S102, the received echo signal carries the additional phase (phase shift amount) applied during the phase shift. Therefore, after receiving the corresponding echo signal, the receiving end needs to perform envelope alignment and phase compensation on the corresponding echo signal, so that the additional phase applied at the transmitting end is eliminated, and the complete target echo signal can be obtained.

[0058] In this embodiment, taking FMCW (Frequency Modulated Continuous Wave) radar as an example, refer to Figure 2 The schematic diagram of the FMCW radar system structure is shown for explanation.

[0059] like Figure 2As shown in the figure, the transmitter generates a high-frequency linear frequency modulation (LFM) signal, which is sent via a power divider to a phase shifter. The phase shifter encodes the LFM signal and transmits it to the transmit antenna Tx via a power amplifier (PA). The transmit antenna radiates the radar signal into free space. Another branch of the power divider feeds the LFM signal into a mixer port for use as a local oscillator (LO). The radar transmit signal propagating in free space is reflected by a target at a distance r, forming a corresponding radar receive signal. This signal is then captured by the receive antenna Rx and, after an amplification chain, enters the other port of the mixer. One port of the mixer receives the local oscillator (LO) signal, while the other port receives the radar receive signal corresponding to the target at distance r. The mixer mixes (downconverts) the radar receive signal corresponding to the target at distance r with the LO signal to generate a sinusoidal signal. After the sinusoidal signal is sampled by the ADC, the corresponding echo signal undergoes signal processing to obtain the target echo signal. This signal processing can include envelope alignment, decoding, and pulse compression.

[0060] In an embodiment of the present application, unlike the solution of avoiding radar cross-interference through V2X technology, the embodiment of the present application divides the high-frequency linear frequency modulation signal into time slots by dividing it into equal parts, and shifts the phase of the high-frequency linear frequency modulation signal in each time slot by the phase shift amount, which is equivalent to performing a certain personalized encoding on the high-frequency linear frequency modulation signal to be transmitted, thereby effectively increasing the signal distinction between this radar and other radars in the adjacent area. On this basis, after obtaining the corresponding echo signal, it is only necessary to phase compensate the corresponding echo signal according to the phase shift amount (that is, decode the corresponding echo signal) to obtain an undistorted target echo signal exclusive to the local radar. Among them, the aforementioned encoding can be implemented by the existing phase shifter in the radar, and the aforementioned decoding can be implemented by the existing signal processing circuit in the radar. That is to say, the present application does not require additional equipment or the use of optimization theory to adaptively switch the effective operating frequency points for multiple radars to avoid cross-interference between radars, and the cost is low, thereby effectively solving the problems of the prior art.

[0061] In this embodiment, when the preset values ​​for the number of equal divisions and the phase shift amount differ between different radars or between the same radar, the different or same radars use different encoding sequences. This allows for distinguishing the received target echo signals and minimizing interference between the radars. For example, if radar A receives echo signals from radar A and radar B, where radar A's encoding sequence is A' and radar B's encoding sequence is B', radar A performs phase compensation on the echo signals from radars A and B using the same method as for compensating the phase shift amount corresponding to A'. This results in a weaker correlation between the target echo signals from radars A and B, thereby suppressing the signal from radar B.

[0062] In a possible implementation, before performing phase compensation on the corresponding echo signal based on the phase shift amount, the method further includes:

[0063] Obtain the maximum delay between the radar transmit signal and the radar receive signal. The radar transmit signal is a phase-shifted high-frequency linear frequency modulation signal, and the radar receive signal is the corresponding echo signal.

[0064] Determine whether the maximum delay time is less than T0 is the time slot after time slot division, and M is a preset value and is greater than 1.

[0065] If the maximum delay time is not less than Then the echo signal is envelope aligned.

[0066] In this embodiment, the radar transmission signal is the signal sent by the transmitter, that is, the high-frequency linear frequency modulation signal after phase shifting. The radar reception signal is the signal received by the receiver, that is, the corresponding echo signal. The delay time is the signal transmission and reception delay between the transmitter and the receiver. M is a preset value and is greater than 1. The maximum delay time τ max Less than It can be expressed as The maximum delay time τ is obtained through the radar's product design indicators max For example, the detection range of forward radar is generally 200-300 meters, and that of corner radar is 100-150 meters. max Indicates the envelope delay time generated by the maximum detection range. For a certain radar product, τ max It is a definite value.

[0067] refer to Figure 3 The schematic diagram of the relationship between the FMCW radar echo signal and the target distance shown in the figure shows that for targets at different distances, not only the echo frequency of the echo signal is different, but also the envelope delay is different. In conventional FMCW processing, this envelope delay is much smaller than the transmission signal time width, so it is often ignored in the signal processing link. For example, when the vehicle-mounted front radar detects the maximum range of 300m, the maximum envelope delay generated is 2us, but the transmission signal time width is generally around 20us or even higher, so the envelope delay can be ignored. For angular radars with a closer detection distance, it is easier to meet the requirement that the envelope delay is much smaller than the transmission signal time width. However, since the present application is encoded on the high-frequency linear frequency modulation signal time width T scale, the equivalent time width of the high-frequency linear frequency modulation signal corresponding to each time slot is reduced, resulting in the envelope delay being non-negligible in some cases. Based on the above considerations, in When this is no longer true, the present application can solve the problem that the envelope delay caused by S102 (encoding) cannot be ignored in some cases by aligning the envelope of the echo signal. When the number of equal parts N is large, the number of bits of the corresponding encoding sequence is large, and the encoding sequence is a long code, such as Figure 4 As shown, Figure 4 This is a schematic diagram of the long coded phase shift provided by the embodiment of the present application. Since the encoding is performed at the transmitting end, it cannot be directly decoded at the receiving end. Figure 3 Analysis shows that if the receiving end directly decodes, there will be envelope delay. Targets at different distances have different delays. Since the time is not aligned, direct decoding cannot be performed at the receiving end. Figure 5 As shown, Figure 5 This is a schematic diagram of the echo signal before envelope alignment provided by the embodiment of the present application, wherein the coding sequence is +1, -1, +1, +1, +1, -1, +1, -1. Time slot division and envelope alignment must be performed before decoding. After envelope alignment, the aligned signal envelope is obtained, such as Figure 6 As shown, Figure 6 This is a schematic diagram of the echo signal after envelope alignment provided in an embodiment of the present application. Envelope alignment can provide a prerequisite for subsequent unified decoding.

[0068] In this embodiment, if the maximum delay time is less than The echo signal does not need to be aligned with the envelope. If the maximum delay time generated by the maximum range is detected It always holds true, that is, when the envelope delay of the farthest target is much less than a phase modulation time length (time slot) T0, the influence of the envelope delay can be ignored, that is, envelope alignment can be omitted at this time. For example, when the maximum detection distance is 150m and T=20us, if N is not greater than 20, then the maximum delay time is less than There is no need to align the envelope at this time. For corner radars and some vehicle-mounted radars with shorter detection distances, the maximum delay time is less than This condition is relatively easy to meet. If the maximum delay time is less than The echo signal does not need to be envelope aligned, and this design can greatly simplify the complexity of the entire system.

[0069] In a possible implementation, performing envelope alignment on the echo signal includes:

[0070] The echo signal is envelope aligned using a group delay filter.

[0071] The group delay function satisfied by the group delay filter is:

[0072]

[0073] Among them, τg (f) is the group delay function, T is the time width of the high-frequency linear frequency modulation signal, B is the frequency band of the high-frequency linear frequency modulation signal, f max is the maximum frequency of the radar received signal, and f is the frequency of the sinusoidal signal generated by mixing the radar received signal and the local oscillator signal corresponding to the target at distance r.

[0074] In this embodiment, the envelope alignment of the received echo signal is performed by designing a group delay filter, wherein the core design parameter of the group delay filter is the "group delay" τ g (f), the group delay function can be used described.

[0075] The frequency of the sinusoidal signal is:

[0076]

[0077] Where T is the time width of the high-frequency linear frequency modulation signal, B is the frequency band of the high-frequency linear frequency modulation signal, c is the speed of light propagating in free space, and r is the distance between the radar transmitter and the target.

[0078] In a possible implementation, before performing phase compensation on the corresponding echo signal based on the phase shift amount, the method further includes:

[0079] Determine whether the number of equal parts is greater than a preset threshold.

[0080] If the number of equal parts is greater than a preset threshold, the echo signal is envelope aligned.

[0081] In this embodiment, the preset threshold value can be set according to actual needs and can be modified. For example, the maximum delay time can be set to not less than The present application considers that when the time width of the high-frequency linear frequency modulation signal is the same, the larger the number of equal parts and the smaller T0, the easier it is to meet the requirement. Therefore, the present application can also determine whether the echo signal needs to be envelope aligned by dividing it into equal parts, that is, the number of bits N of the coding sequence.

[0082] In this embodiment, envelope alignment can be achieved through a group delay filter. Specifically, the envelope alignment of the echo signal can be performed through a digital IIR filter after the ADC at the receiving end.

[0083] In one possible implementation, a method for determining a phase shift amount includes:

[0084] Generate an N-bit code sequence according to the preset code format, where N is the number of equal parts.

[0085] The phase shift amount of the high frequency linear frequency modulation signal in each time slot is determined according to the coding of each bit of the N-bit coding sequence.

[0086] In this embodiment, the preset encoding format can be pseudo-random phase encoding. The specific encoding format can be a binary code or a multi-phase code, such as Barker code, m-sequence, chaotic coding, P4 code, CAZAC (Constant Amplitude Zero Auto Correlation), etc. This embodiment does not limit the specific encoding format. In this embodiment, the phase shift corresponding to different code values ​​can be set voluntarily. An N-bit encoding sequence can obtain N phase shifts φ1, φ2, ...φ N ,like Figure 7 As shown, Figure 7 This is a schematic diagram of determining the phase shift provided by an embodiment of the present application. This embodiment controls the initial phase of the high-frequency linear frequency modulation signal within the time period by adjusting the phase shifter on the time slot T0. The phase value adjusted by the phase shifter is the phase shift amount corresponding to the code value. For example: N = 13, the encoding format is Barker code, +1 represents a phase shift amount of +180°, -1 represents a phase shift amount of 0°, and the 13-bit Barker code sequence is {+1, +1, +1, +1, +1, -1, -1, +1, +1, -1, +1, -1, +1}. N = 13, then the high-frequency linear frequency modulation signal is divided into 13 equal parts. The phase shift amounts of the high-frequency linear frequency modulation signal after the time slot division are +180°, +180°, +180°, +180°, +180°, 0°, 0°, +180°, +180°, 0°, +180°, 0°, +180°, 0°, +180°.

[0087] In this embodiment, after envelope alignment, the envelopes of targets at different distances received by the receiver have the same time base. For echo signals that do not require envelope alignment, the impact of envelope delay is negligible and they also have the same time base. The specific method for obtaining the target echo signal by time slot division and phase compensation based on the phase shift amount is as follows: If envelope alignment is not performed, starting from the starting position of the echo signal, within the time slot range, the phase shift amounts φ1, φ2, ...φ applied when phase shifting the high-frequency linear frequency modulation signal after time slot division are used. N Perform phase compensation. If envelope alignment is performed, the phase shift amount φ1, φ2, ...φ applied when phase shifting the high-frequency linear frequency modulation signal after time slot division is based on the echo signal envelope alignment position as the starting point within the time slot range. N Phase compensation is performed. The phase compensation method is: multiply the time interval corresponding to the echo signal sampled by the ADC by the following phase factor term In this embodiment, after such phase compensation (decoding), the extra phase applied at the transmitting end is eliminated, that is, the target echo signal is completely restored at the receiving end, such as Figure 8 As shown, Figure 8 This is a schematic diagram of a target echo signal after phase compensation, as provided in an embodiment of the present application. In this embodiment, the transmitter utilizes a chip's internal phase shifter to perform local waveform encoding during the transmission time. At the receiver, phase compensation is performed on echo signals from targets at different distances to recover the locally specific, undistorted target echo signal. By applying different local waveform coding sequences to different radars, the ability to suppress cross-interference between radars can be further improved.

[0088] In a possible implementation, the time slots after time slot division are: Wherein, T0 is the time slot after time slot division, T is the time width of the high-frequency linear frequency modulation signal, and N is the number of equal parts.

[0089] In this embodiment, when the time width of the high-frequency linear frequency modulation signal is the same, the larger the number of equally divided parts, the smaller the time slot. When the number of equally divided parts is larger, the more phase shift amounts need to be applied.

[0090] In a possible implementation, each time slot corresponds to a phase shift amount, and the phase of the high-frequency linear frequency modulation signal after the time slot is divided is shifted based on the phase shift amount, including:

[0091] The high-frequency linear frequency modulation signal of each time slot is phase-shifted based on the phase shift amount corresponding to each time slot.

[0092] In this embodiment, the phase shift amounts applied when the high-frequency linear frequency modulation signals of each time slot are phase shifted may be different. By applying different phase shift amounts, the complexity of the high-frequency linear frequency modulation signal waveform can be increased, the correlation between the local radar target echo signal and the interference radar target echo signal can be reduced, and the anti-interference capability can be effectively improved.

[0093] In the embodiments of this application, after envelope alignment and phase compensation, the target echo signal is well recovered at the receiver. Pulse compression can subsequently be achieved through matched filtering. Taking FMCW radar as an example, the most common pulse compression method is FFT. FFT processing can be used to obtain target distance information. A complete automotive radar processing flow requires subsequent speed and angle measurement. For this purpose, the classic FFT MTD and MIMO angle measurement methods can be used and will not be further described here.

[0094] Taking FMCW radar as an example, the processing flow of the present application solution can be expressed as follows: the FMCW signal with a time width of T is divided into N time slots; in each time slot, the phase shifter at the transmitting end shifts the phase of the FMCW signal; the receiving end down-converts the radar received signal and samples it with ADC to obtain the echo signal; if the condition is satisfied, Then the phase compensation of the echo signal is performed according to the phase shift amount applied by the transmitter (if it does not meet the The echo signal is envelope-aligned using a group delay filter; the signal after envelope alignment is phase-compensated according to the phase shift applied by the transmitter; the target distance is acquired within a single cycle using FFT; and speed and angle measurements and subsequent processing are performed.

[0095] This application takes into account the problem that existing ordinary radar transmitters and receivers are unable to apply complex anti-interference technologies. Therefore, the inventors of this application have designed a radar signal processing method that can be widely applied to existing ordinary radar transmitters and receivers to solve the above problem.

[0096] In the embodiments of the present application, complex waveforms are an effective means of radar anti-interference. In dense driving environments, mutual interference between multiple vehicles is particularly serious. Taking FMCW radar as an example, traditional FMCW waveforms have low degrees of freedom, making it difficult to form effective anti-interference. However, the solution based on the present application can increase the complexity of waveform design by encoding the FMCW waveform at the transmitting end. Furthermore, by assigning a set of coding sequences with different N value lengths to different radar terminals, the local radar target echo signal and the interfering radar target echo signal can be decorrelated. In this way, at the local radar receiving end, the echo generated by the local radar will receive ideal coherent processing, achieving processing gain. The interfering radar signal, due to its mismatch with the local coding, will be greatly suppressed at the receiving end, thereby improving anti-interference performance.

[0097] This application considers that while PMCW offers advantages in complex waveforms, PMCW chip technology is currently immature and relatively expensive. Consequently, the current mainstream application is still the relatively low-cost FMCW radar. Therefore, this application's solution is designed based on FMCW radar. This proposed solution is entirely based on the existing FMCW platform, requiring no additional hardware modules, effectively reducing costs and thus possessing significant practical value.

[0098] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0099] The following are device embodiments of the present application. For details not fully described therein, please refer to the corresponding method embodiments described above.

[0100] Figure 9 A schematic diagram of the structure of a radar signal processing device provided in an embodiment of the present application is shown. For ease of explanation, only the parts related to the embodiment of the present application are shown, which are detailed as follows:

[0101] like Figure 9 As shown, the radar signal processing device 90 includes:

[0102] The data acquisition module 91 is used to acquire a preset number of equal parts and a preset phase shift amount after generating the high-frequency linear frequency modulation signal.

[0103] The first signal processing module 92 is configured to divide the high-frequency linear frequency modulation signal into time slots based on an equal number of parts, and perform phase shifting on the high-frequency linear frequency modulation signal after the time slot division based on a phase shift amount.

[0104] The signal transceiver module 93 is used to transmit the phase-shifted high-frequency linear frequency modulation signal and receive the corresponding echo signal.

[0105] The second signal processing module 94 is configured to perform time slot division and phase compensation on the corresponding echo signal based on the phase shift amount to obtain a target echo signal.

[0106] In one possible implementation, the second signal processing module 94 is configured to obtain a maximum delay between a radar transmit signal and a radar receive signal before performing phase compensation on the corresponding echo signal based on the phase shift amount. The radar transmit signal is a phase-shifted high-frequency linear frequency modulation signal, and the radar receive signal is the corresponding echo signal.

[0107] Determine whether the maximum delay time is less than Wherein, T0 is the time slot, and M is a preset value and is greater than 1.

[0108] If the maximum delay time is not less than Then the echo signal is envelope aligned.

[0109] In a possible implementation, the second signal processing module 94 is configured to determine a group delay function.

[0110] Perform envelope alignment on the echo signal, including:

[0111] The echo signal is envelope aligned using a group delay filter.

[0112] The group delay function satisfied by the group delay filter is:

[0113]

[0114] Among them, τ g(f) is the group delay function, T is the time width of the high-frequency linear frequency modulation signal, B is the frequency band of the high-frequency linear frequency modulation signal, f max is the maximum frequency of the radar received signal, and f is the frequency of the sinusoidal signal generated by mixing the radar received signal and the local oscillator signal corresponding to the target at distance r.

[0115] In a possible implementation, the second signal processing module 94 is configured to determine whether the number of equal divisions is greater than a preset threshold before performing phase compensation on the corresponding echo signal based on the phase shift amount.

[0116] If the number of equal parts is greater than a preset threshold, the echo signal is envelope aligned.

[0117] In a possible implementation, the data acquisition module 91 is configured to determine a phase shift amount.

[0118] Generate an N-bit code sequence according to the preset code format, where N is the number of equal parts.

[0119] The phase shift amount of the high frequency linear frequency modulation signal in each time slot is determined according to the coding of each bit of the N-bit coding sequence.

[0120] In a possible implementation, the first signal processing module 92 is configured to calculate a time slot.

[0121] The time slots after time slot division are: Wherein, T0 is the time slot, T is the time width of the high-frequency linear frequency modulation signal, and N is the number of equal parts.

[0122] In a possible implementation, the first signal processing module 92 is configured to perform phase shift on the high-frequency linear frequency modulation signal after time slot division based on a phase shift amount.

[0123] Each time slot corresponds to a phase shift amount, and the high-frequency linear frequency modulation signal divided by the time slot is phase shifted based on the phase shift amount, including:

[0124] The high-frequency linear frequency modulation signal of each time slot is phase-shifted based on the phase shift amount corresponding to each time slot.

[0125] The embodiment of the present application further provides a radar, which includes a processing terminal, see Figure 10 , Figure 10 Schematic diagram of the processing terminal of the radar provided in the embodiment of the present application. Figure 10 As shown, the processing terminal 20 of this embodiment includes: a processor 21, a memory 22, and a computer program 23 stored in the memory 22 and executable on the processor 21. When the processor 21 executes the computer program 23, the steps in the above-mentioned various radar signal processing method embodiments are implemented, such as Figure 1Alternatively, when the processor 21 executes the computer program 23, the functions of the modules in the above-mentioned device embodiments are realized, for example, Figure 9 The functions of modules 91 to 94 are shown.

[0126] For example, the computer program 23 may be divided into one or more modules, one or more modules being stored in the memory 22 and executed by the processor 21 to complete the present application. One or more modules may be a series of computer program instruction segments capable of completing specific functions, and the instruction segments are used to describe the execution process of the computer program 23 in the processing terminal 20. For example, the computer program 23 may be divided into Figure 9 Modules 91 to 94 are shown.

[0127] The processing terminal 20 can be a computing device such as a desktop computer, a notebook, a PDA, or a cloud server. The processing terminal 20 can include, but is not limited to, a processor 21 and a memory 22. It will be understood by those skilled in the art that Figure 10 This is merely an example of the processing terminal 20 and does not constitute a limitation on the processing terminal 20 . The processing terminal 20 may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the terminal may also include input and output devices, network access devices, buses, etc.

[0128] The processor 21 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0129] The memory 22 can be an internal storage unit of the processing terminal 20, such as the hard disk or memory of the processing terminal 20. The memory 22 can also be an external storage device of the processing terminal 20, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) card, a flash memory card, etc. equipped with the processing terminal 20. Furthermore, the memory 22 can include both the internal storage unit of the processing terminal 20 and an external storage device. The memory 22 is used to store computer programs and other programs and data required by the terminal. The memory 22 can also be used to temporarily store data that has been output or is about to be output.

[0130] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0131] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0132] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0133] In the embodiments provided in this application, it should be understood that the disclosed devices / terminals and methods can be implemented in other ways. For example, the device / terminal embodiments described above are merely illustrative. For example, the division of modules or units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0134] Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0135] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0136] If the integrated module / unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application can implement all or part of the processes in the above-mentioned method embodiments by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When executed by a processor, the computer program can implement the steps of each of the above-mentioned radar signal processing method embodiments. The computer program includes computer program code, which can be in source code form, object code form, executable file, or some intermediate form. Computer-readable media can include: any entity or device capable of carrying computer program code, recording media, USB flash drives, mobile hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signals, telecommunications signals, and software distribution media. It should be noted that the content included in the computer-readable medium can be appropriately increased or decreased based on the requirements of legislation and patent practice in a jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media does not include electric carrier signals and telecommunications signals.

[0137] The above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should be included in the scope of protection of the present application.

Claims

1. A radar signal processing method, characterized in that: include: After generating the high-frequency linear frequency modulation signal, obtaining a preset number of equal parts and a preset phase shift amount; Dividing the high-frequency linear frequency modulation signal into time slots based on the number of equal parts, and performing phase shifting on the high-frequency linear frequency modulation signal after the time slot division based on the phase shift amount; Transmitting a phase-shifted high-frequency linear frequency modulation signal and receiving the corresponding echo signal; The corresponding echo signal is time-slot divided and phase compensated based on the phase shift amount to obtain a target echo signal.

2. The method according to claim 1, characterized in that Before performing phase compensation on the corresponding echo signal based on the phase shift amount, the method further includes: Obtaining a maximum delay time between a radar transmit signal and a radar receive signal; wherein the radar transmit signal is a phase-shifted high-frequency linear frequency modulation signal, and the radar receive signal is a corresponding echo signal; Determine whether the maximum delay time is less than Wherein, T0 is the time slot after the time slot division, and M is a preset value and is greater than 1; If the maximum delay time is not less than Then, envelope alignment is performed on the echo signal.

3. The method according to claim 2, characterized in that The performing envelope alignment on the echo signal includes: performing envelope alignment on the echo signal through a group delay filter; The group delay function satisfied by the group delay filter is: Among them, τ g (f) is the group delay function, T is the time width of the high-frequency linear frequency modulation signal, B is the frequency band of the high-frequency linear frequency modulation signal, f max is the maximum frequency of the radar received signal, and f is the frequency of the sinusoidal signal generated by mixing the radar received signal and the local oscillator signal corresponding to the target at distance r.

4. The method according to claim 1, wherein Before performing phase compensation on the corresponding echo signal based on the phase shift amount, the method further includes: Determining whether the number of equal parts is greater than a preset threshold; If the number of equal parts is greater than the preset threshold, envelope alignment is performed on the echo signal.

5. The method according to claim 1, characterized in that The method for determining the phase shift amount includes: Generate an N-bit code sequence according to a preset code format, where N is the number of equal parts; The phase shift amount of the high frequency linear frequency modulation signal in each time slot is determined according to the coding of each bit of the N-bit coding sequence.

6. The method according to claim 1, wherein The time slots after the time slot division are: Wherein, T0 is the time slot after the time slot division, T is the time width of the high-frequency linear frequency modulation signal, and N is the number of equal parts.

7. The method according to claim 1, characterized in that Each time slot corresponds to a phase shift amount, and the phase shifting of the high-frequency linear frequency modulation signal after the time slot division based on the phase shift amount includes: The high-frequency linear frequency modulation signal of each time slot is phase-shifted based on the phase shift amount corresponding to each time slot.

8. A radar signal processing device, characterized in that: include: A data acquisition module, configured to acquire a preset number of equal parts and a preset phase shift amount after generating a high-frequency linear frequency modulation signal; a first signal processing module, configured to divide the high-frequency linear frequency modulation signal into time slots based on the number of equal divisions, and perform phase shifting on the high-frequency linear frequency modulation signal after the time slot division based on the phase shift amount; The signal transceiver module is used to transmit the phase-shifted high-frequency linear frequency modulation signal and receive the corresponding echo signal; The second signal processing module is configured to perform time slot division and phase compensation on the corresponding echo signal based on the phase shift amount to obtain a target echo signal.

9. A radar comprising a processing terminal, wherein the processing terminal comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

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

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