Low-cost lightweight single-bit multiplexing array radar signal processing method and system

Abstract

A low-cost lightweight single-bit multiplexing array radar signal processing method and system. The method comprises: on the basis of a radio frequency multiplexer, acquiring an array echo signal, and preprocessing the array echo signal to obtain a first zero-intermediate-frequency signal and a second zero-intermediate-frequency signal (S100); performing single-bit synchronous sampling on the first zero-intermediate-frequency signal and the second zero-intermediate-frequency signal to obtain symbol data (S200); and on the basis of the symbol data, estimating an intermediate parameter, and on the basis of the estimation result of the intermediate parameter, calculating target information (S300). The problem of a traditional frequency-modulated continuous wave array radar using a plurality of receivers and a multi-bit analog-to-digital converter to acquire echo signals from a plurality of antennas, resulting in a complex hardware system, a large size, a heavy load and high power consumption, thus limiting the application of the radar in a low-cost and small-payload unmanned system is solved.

Description

Low-cost and lightweight single-bit multiplexing array radar signal processing method and system Technical Field

[0001] The present invention relates to the field of radar technology, and in particular to a low-cost and lightweight single-bit multiplexing array radar signal processing method, system, terminal and storage medium. Background Art

[0002] Currently, traditional frequency-modulated continuous-wave array radars obtain echo signals from multiple antennas by using multiple receivers and multi-bit analog-to-digital converters (ADCs). However, multiple receivers and multi-bit ADCs will undoubtedly lead to complex hardware systems, large size, heavy load and high power consumption. These problems limit the application of radar in low-cost and small-payload unmanned systems such as drones, unmanned ships and unmanned vehicles.

[0003] Therefore, the existing technology still needs to be improved and developed.

[0004] Summary of the Invention

[0005] The main purpose of the present invention is to provide a low-cost and lightweight single-bit multiplexing array radar signal processing method, system, terminal and storage medium. The purpose is to solve the problem in the prior art that traditional frequency-modulated continuous wave array radars obtain echo signals from multiple antennas by using multiple receivers and multi-bit analog-to-digital converters, resulting in complex hardware systems, large size, heavy load and high power consumption, thereby limiting the application of radar in low-cost and small-payload unmanned systems.

[0006] To achieve the above-mentioned object, the first aspect of the present invention provides a low-cost and lightweight single-bit multiplexing array radar signal processing method, wherein the low-cost and lightweight single-bit multiplexing array radar signal processing method includes:

[0007] Acquiring an array echo signal based on a radio frequency multiplexer, and preprocessing the array echo signal to obtain a first zero intermediate frequency signal and a second zero intermediate frequency signal;

[0008] Performing single-bit synchronous sampling on the first zero-IF signal and the second zero-IF signal to obtain symbol data;

[0009] According to the symbol data, intermediate parameters are estimated, and target information is calculated based on the estimation results of the intermediate parameters.

[0010] Optionally, the step of acquiring an array echo signal based on a radio frequency multiplexer and preprocessing the array echo signal to obtain a first zero intermediate frequency signal and a second zero intermediate frequency signal includes:

[0011] All receiving antennas are sequentially connected to a zero intermediate frequency receiver based on a radio frequency multiplexer, and the zero intermediate frequency receiver receives an array echo signal;

[0012] The array echo signal is preprocessed to obtain a first zero intermediate frequency signal and a second zero intermediate frequency signal that are orthogonal to each other, wherein the preprocessing includes limiting, low noise amplification, orthogonal demodulation and anti-aliasing filtering operations.

[0013] Optionally, the step of performing single-bit synchronous sampling on the first zero-IF signal and the second zero-IF signal to obtain symbol data includes:

[0014] Performing single-bit synchronous sampling on the first zero-intermediate frequency signal and the second zero-intermediate frequency signal based on a single-bit analog-to-digital converter, and extracting sign bits of the first zero-intermediate frequency signal and the second zero-intermediate frequency signal;

[0015] Sign data is generated according to the sign bit.

[0016] Optionally, the step of estimating intermediate parameters according to the symbol data, and calculating target information according to the estimation results of the intermediate parameters includes:

[0017] estimating the intermediate parameter according to the symbol data and a sampling frequency estimation algorithm to obtain the estimation result;

[0018] According to the estimation result, the target information is obtained using a target parameter calculation formula.

[0019] Optionally, the step of estimating the intermediate parameter according to the symbol data and a sampling frequency estimation algorithm to obtain the estimation result includes:

[0020] Set the intermediate parameters according to the preset intermediate parameter setting formula;

[0021] constructing a first two-dimensional frequency pair and a second two-dimensional frequency pair according to the intermediate parameters;

[0022] The first two-dimensional frequency pair and the second two-dimensional frequency pair are estimated according to the symbol data to obtain the estimation result.

[0023] Optionally, the step of estimating the first two-dimensional frequency pair and the second two-dimensional frequency pair according to the symbol data to obtain the estimation result includes:

[0024] Acquire a complex signal representation constructed from the symbolic data, and construct a signal model based on the symbolic data and the complex signal representation;

[0025] Calculating a covariance matrix according to the signal model, and obtaining a noise subspace according to the covariance matrix;

[0026] The estimation result is generated according to the noise subspace.

[0027] Optionally, the step of obtaining the target information by using a target parameter calculation formula according to the estimation result includes:

[0028] constructing a first two-dimensional target parameter pair and a second two-dimensional target parameter pair;

[0029] Solving the first two-dimensional target parameter pair and the second two-dimensional target parameter pair according to the estimation result and the target parameter calculation formula to obtain preset target information;

[0030] According to the minimum Mahalanobis distance pairing principle, three-dimensional target parameters are paired with the preset target information to obtain the target information.

[0031] A second aspect of the present invention provides a low-cost, lightweight, single-bit multiplexing array radar signal processing system, wherein the low-cost, lightweight, single-bit multiplexing array radar signal processing system comprises:

[0032] a signal preprocessing module, configured to obtain an array echo signal based on a radio frequency multiplexer, and preprocess the array echo signal to obtain a first zero intermediate frequency signal and a second zero intermediate frequency signal;

[0033] A symbol data acquisition module, configured to perform single-bit synchronous sampling on the first zero-IF signal and the second zero-IF signal to obtain symbol data;

[0034] The target information generating module is used to estimate the intermediate parameters according to the symbol data, and calculate the target information according to the estimation results of the intermediate parameters.

[0035] A third aspect of the present invention provides a terminal, comprising a memory, a processor, and a low-cost, lightweight single-bit multiplexed array radar signal processing program stored in the memory and executable on the processor. When the low-cost, lightweight single-bit multiplexed array radar signal processing program is executed by the processor, the terminal implements any one of the steps of the low-cost, lightweight single-bit multiplexed array radar signal processing method.

[0036] A fourth aspect of the present invention provides a computer-readable storage medium, on which is stored a low-cost, lightweight, single-bit multiplexed array radar signal processing program. When the low-cost, lightweight, single-bit multiplexed array radar signal processing program is executed by a processor, it implements any one of the steps of the low-cost, lightweight, single-bit multiplexed array radar signal processing method.

[0037] As can be seen from the above, in the solution of the present invention, an array echo signal is obtained based on a radio frequency multiplexer, and the array echo signal is preprocessed to obtain a first zero-intermediate frequency signal and a second zero-intermediate frequency signal; single-bit synchronous sampling is performed on the first and second zero-intermediate frequency signals to obtain symbol data; intermediate parameters are estimated based on the symbol data, and target information is calculated based on the estimated results of the intermediate parameters.

[0038] Compared with the existing technology, the conventional frequency modulated continuous wave array radar obtains echo signals from multiple antennas by using multiple receivers and multi-bit analog-to-digital converters, which results in a complex hardware system, large size, heavy load, and high power consumption, thereby limiting the application of radar in low-cost and small-load unmanned systems. The present invention obtains data of the received antenna array echo signal through a radio frequency multiplexer, making the system similar to the classic digital array radar, with a higher degree of freedom in signal processing and also capable of achieving super-resolution estimation of the target angle; at the same time, the present invention uses a multiplexer to receive the array echo signal. The array echo signal is obtained and the radar target parameters are estimated, thereby achieving better ranging and speed measurement performance. In addition, in the present invention, a multiplexer is used to receive the array echo signal, and the array echo signal is processed by the receiver. In order to ensure the data rate of the array echo signal, that is, the number of radar coverage range detections per minute, the pulse width of the radar signal is usually shortened, which is conducive to multiplexing of the zero intermediate frequency receiver and can greatly increase the number of receiver multiplexing. Therefore, the present invention achieves a low-cost and lightweight design, making it more convenient to apply in low-cost and small-payload unmanned systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0040] FIG1 is a schematic flow chart of a low-cost and lightweight single-bit multiplexing array radar signal processing method provided by an embodiment of the present invention;

[0041] FIG2 is a schematic diagram of the actual frequency of a transmitted signal in a low-cost and lightweight single-bit multiplexing array radar signal processing method provided by an embodiment of the present invention;

[0042] FIG3 is a schematic diagram of a system structure corresponding to a low-cost and lightweight single-bit multiplexing array radar signal processing method provided by an embodiment of the present invention;

[0043] FIG4 is a top view of a pseudo-spectrum in the slow-time-fast-time dimension in a low-cost and lightweight single-bit multiplexing array radar signal processing method provided by an embodiment of the present invention;

[0044] FIG5 is a top view of a pseudo-spectrum in the space-slow time dimension in a low-cost and lightweight single-bit multiplexing array radar signal processing method provided by an embodiment of the present invention;

[0045] FIG6 is a schematic diagram of a distance estimation performance curve of a low-cost and lightweight single-bit multiplexing array radar signal processing method provided by an embodiment of the present invention;

[0046] FIG7 is a schematic diagram of a speed estimation performance curve of a low-cost and lightweight single-bit multiplexing array radar signal processing method provided by an embodiment of the present invention;

[0047] FIG8 is a schematic diagram of an angle estimation performance curve of a low-cost and lightweight single-bit multiplexing array radar signal processing method provided by an embodiment of the present invention;

[0048] FIG9 is a schematic diagram of the components of a low-cost, lightweight, single-bit multiplexing array radar signal processing system according to an embodiment of the present invention;

[0049] FIG10 is a block diagram showing the internal structure of a terminal according to an embodiment of the present invention. DETAILED DESCRIPTION

[0050] In the following description, specific details such as particular system structures and techniques are provided for purposes of illustration and not limitation to facilitate a thorough understanding of the embodiments of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid obscuring the description of the present invention with unnecessary detail.

[0051] It will be understood that when used in this specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0052] It should also be understood that the terms used in the present specification are for the purpose of describing particular embodiments only and are not intended to limit the present invention. As used in the present specification and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0053] It should be further understood that the term "and / or" used in the present description and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0054] As used in this specification and the appended claims, the term "if" can be interpreted as meaning "when" or "upon" or "in response to determining" or "in response to being classified into," depending on the context. Similarly, the phrase "if it is determined" or "if it is classified into [described condition or event]" can be interpreted as meaning "upon determination" or "in response to determining" or "upon classification into [described condition or event]" or "in response to being classified into [described condition or event]," depending on the context.

[0055] The following is a clear and complete description of the technical solutions in the embodiments of the present invention, in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0056] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0057] At present, traditional frequency-modulated continuous wave array radars obtain echo signals from multiple antennas by using multiple receivers and multi-bit analog-to-digital converters. However, multiple receivers and multi-bit analog-to-digital converters will undoubtedly lead to problems such as complex hardware systems, large size, heavy load and high power consumption. These problems limit the application of radar in low-cost and small-payload unmanned systems such as drones, unmanned ships and unmanned vehicles.

[0058] To address at least one of the aforementioned problems, the present invention provides a low-cost, lightweight, single-bit multiplexed array radar signal processing method, system, terminal, and storage medium. Specifically, an array echo signal is acquired based on a radio frequency multiplexer, and the array echo signal is preprocessed to obtain a first zero-intermediate frequency signal and a second zero-intermediate frequency signal. Single-bit synchronous sampling is performed on the first and second zero-intermediate frequency signals to obtain symbol data. Intermediate parameters are estimated based on the symbol data, and target information is calculated based on the estimated intermediate parameters.

[0059] The present invention uses a radio frequency multiplexer to obtain data from the antenna array echo signal, making the system similar to a classic digital array radar, with a high degree of signal processing freedom and super-resolution estimation of target angles. Simultaneously, the present invention utilizes a multiplexer to receive the array echo signal, obtains the array echo signal, and estimates radar target parameters, thereby achieving better ranging and speed measurement performance. Furthermore, the present invention uses a multiplexer to receive the array echo signal and processes the array echo signal through a receiver. To ensure the data rate of the array echo signal, that is, the number of radar coverage area detections per minute, the pulse width of the radar signal is typically shortened, which facilitates multiplexing of the zero intermediate frequency receiver and greatly increases the number of receiver multiplexing times. This enables the present invention to achieve a low-cost and lightweight design, making it more convenient to apply in low-cost and small-payload unmanned systems.

[0060] Exemplary Methods

[0061] As shown in FIG1 , an embodiment of the present invention provides a low-cost, lightweight single-bit multiplexing array radar signal processing method. Specifically, the low-cost, lightweight single-bit multiplexing array radar signal processing method includes the following steps:

[0062] Step S100 : acquiring an array echo signal based on a radio frequency multiplexer, and preprocessing the array echo signal to obtain a first zero intermediate frequency signal and a second zero intermediate frequency signal.

[0063] It should be noted that in the present application, before receiving and acquiring the array echo signal, the present application controls the transmitter by the signal transceiver control unit to radiate M×P cycles of linear frequency modulated continuous wave (LFMCW) signals through the transmitting antenna, where M is the number of receiving antennas, the time taken to continuously transmit M cycles is the pulse repetition period, and P is the number of pulse repetition periods.

[0064] Based on the outward radiation of the linear frequency modulated continuous wave signal, the present application uses a signal transceiver control unit to obtain array echo signals through a radio frequency multiplexer within M×P cycles of transmitting the LFMCW signal. Each acquired array echo signal is preprocessed to obtain a first zero intermediate frequency signal and a second zero intermediate frequency signal corresponding to each array echo signal. In any one transmission cycle, only one of the antennas enters the receiver through the radio frequency multiplexer. The antenna unit or subarray antenna can be any form of antenna.

[0065] It should be noted that in the present application, when the transmitter is controlled by the signal transceiver control unit to radiate M×P cycles of linear frequency modulated continuous wave signals through the transmitting antenna, and at the same time, the RF multiplexer is controlled by the signal transceiver control unit, it is carried out through the timing shown in Figure 2. As shown in Figure 2, according to the timing of Figure 2, the RF multiplexer sequentially accesses the signal of the array antenna, wherein the array configuration of the receiving array antenna is a uniform linear array, wherein T1 is the pulse width of the transmitted LFMCW signal, T2 is the pulse period of the transmitted LFMCW signal, T3 is the pulse repetition period, and B is the RF bandwidth.

[0066] Furthermore, the step of acquiring the array echo signal based on the radio frequency multiplexer and preprocessing the array echo signal to obtain the first zero intermediate frequency signal and the second zero intermediate frequency signal includes:

[0067] All receiving antennas are sequentially connected to a zero intermediate frequency receiver based on a radio frequency multiplexer, and the zero intermediate frequency receiver receives an array echo signal;

[0068] The array echo signal is preprocessed to obtain a first zero intermediate frequency signal and a second zero intermediate frequency signal that are orthogonal to each other, wherein the preprocessing includes limiting, low noise amplification, orthogonal demodulation and anti-aliasing filtering operations.

[0069] Specifically, in the present application, during the M×P cycles of transmitting the LFMCW signal, the signal transceiver control unit, through the radio frequency multiplexer, selects the receiving antennas in a cyclic manner and sequentially selects the M antennas to be connected to the zero intermediate frequency receiver. The duration of each antenna accessing the receiver is the period of the transmitting signal, so the time spent on a single cyclic rotation is the period of the M transmitting signal, and a total of P cyclic rotations are performed for M×P periods. The zero intermediate frequency receiver obtains mutually orthogonal I and Q zero intermediate frequency signals by limiting, low-noise amplifying, orthogonal demodulating and anti-aliasing filtering the array echo signal that is selected for access. The first zero intermediate frequency signal is the I zero intermediate frequency signal, and the second zero intermediate frequency signal is the Q zero intermediate frequency signal.

[0070] Step S200 : performing single-bit synchronous sampling on the first zero-IF signal and the second zero-IF signal to obtain symbol data.

[0071] It should be noted that in the present application, a single-bit analog-to-digital converter (ADC), i.e., a single-bit ADC, implements single-bit synchronous sampling of the first zero-IF signal and the second zero-IF signal, i.e., extracts the signal sign bit, wherein the extraction of the signal sign bit can be any form that implements the function of the sign function sign(x), where x is used to represent the function variable.

[0072] Furthermore, the step of performing single-bit synchronous sampling on the first zero-IF signal and the second zero-IF signal to obtain symbol data includes:

[0073] Performing single-bit synchronous sampling on the first zero-intermediate frequency signal and the second zero-intermediate frequency signal based on a single-bit analog-to-digital converter, and extracting sign bits of the first zero-intermediate frequency signal and the second zero-intermediate frequency signal;

[0074] Sign data is generated according to the sign bit.

[0075] Specifically, in the present application, a single-bit analog-to-digital converter is used to synchronously sample the first zero-IF signal and the second zero-IF signal output by the zero-IF receiver, so that the sign bit of the radar echo zero-IF signal can be obtained. Symbol data can be generated based on the sign bits of the first zero-IF signal and the second zero-IF signal of the multiple array echo signals obtained by each antenna.

[0076] It should be noted that a single-bit ADC refers to an ADC with only one quantization bit. That is, sampling based on a single-bit ADC only obtains the sign bit of the signal. Mathematically, it can be represented by the sign function sign(x). When x ≥ 0, sign(x) = 1, and when x < 0, sign(x) = -1.

[0077] Step S300: estimating intermediate parameters according to the symbol data, and calculating target information according to the estimation results of the intermediate parameters.

[0078] It should be noted that in the present application, based on the symbol data obtained, a signal processor can be used to process the corresponding symbol data, that is, the intermediate parameters are estimated by the signal processor, and the target information is calculated based on the estimated results of the intermediate parameters, where the target information is the distance, speed and angle of the target.

[0079] The step of estimating intermediate parameters according to the symbol data, and calculating target information according to the estimation results of the intermediate parameters includes:

[0080] estimating the intermediate parameter according to the symbol data and a sampling frequency estimation algorithm to obtain the estimation result;

[0081] According to the estimation result, the target information is obtained using a target parameter calculation formula.

[0082] Specifically, in this application, after obtaining the symbol data, according to the LFMCW radar principle, the array echo signal of the mth receiving antenna passes through the zero intermediate frequency receiver and the single-bit ADC, and the obtained complex signal can be expressed by the following formula:

[0083] in, and Represent the real part and imaginary part operations respectively, is the imaginary unit, m=1,…,M, where M is the number of receiving antennas. m (l,p) is the signal of the lth sampling point in the p pulses received by the mth array element, p=1,…,P, l=1,…,L, L is the number of sampling points in a single pulse period; α i , γ i , β i , δ i and are respectively the reflection coefficient, frequency in the range dimension, spatial frequency in the azimuth dimension, Doppler frequency in the velocity dimension and initial phase of the i-th point target; where γ i =2r i B / T1c, beta i =dsin(θ i ) / λ,δ i =2v i / λ,r i ,θ i and v i are the distance, direction and speed of the i-th point target respectively; w m is the noise component in the array echo signal received by the zero intermediate frequency receiver of the mth antenna; T2 is the pulse period of the transmitted LFMCW signal, T3 is the pulse repetition period, T s is the sampling period of the single-bit ADC; i = 1,…,K, where K is the number of radar targets, i.e., the total number of sampling points; λ is the RF carrier wavelength.

[0084] It should be noted that, based on the symbol data, the intermediate parameters are estimated according to the symbol data and the sampling frequency estimation algorithm to obtain the estimation result, and based on the estimation result, the target information is obtained using the target parameter calculation formula.

[0085] Furthermore, the step of estimating the intermediate parameter according to the symbol data and the sampling frequency estimation algorithm to obtain the estimation result includes:

[0086] Set the intermediate parameters according to the preset intermediate parameter setting formula;

[0087] constructing a first two-dimensional frequency pair and a second two-dimensional frequency pair according to the intermediate parameters;

[0088] The first two-dimensional frequency pair and the second two-dimensional frequency pair are estimated according to the symbol data to obtain the estimation result.

[0089] Specifically, the intermediate parameter setting formula preset in this application is as follows:

[0090] Among them, b i 、g i and h i are intermediate parameters, which are the digital angular frequencies of the radar target echo signal in the fast time domain, spatial domain and slow time domain respectively.

[0091] Based on the introduction of intermediate parameters, y m (l,p) can be further expressed as:

[0092] In the parameter estimation process, first estimate b i 、g i and h i , and then the target distance r can be inversely solved through the target parameter calculation formula i 、Direction θ i and speed v i In the formula, use and Respectively represent b i 、g i 、h i 、r i ,θ i and v i The estimated amount.

[0093] Furthermore, in the present application, a first two-dimensional frequency pair and a second two-dimensional frequency pair are constructed according to the intermediate parameters, that is, and The first two-dimensional frequency pair and the second two-dimensional frequency pair are estimated according to the symbol data to obtain the estimation result.

[0094] Furthermore, the step of estimating the first two-dimensional frequency pair and the second two-dimensional frequency pair according to the symbol data to obtain the estimation result includes:

[0095] Acquire a complex signal representation constructed from the symbolic data, and construct a signal model based on the symbolic data and the complex signal representation;

[0096] Calculating a covariance matrix according to the signal model, and obtaining a noise subspace according to the covariance matrix;

[0097] The estimation result is generated according to the noise subspace.

[0098] It should be noted that and When estimating and Make an estimate, where and The estimation method is the same.

[0099] Specifically, first obtain the complex signal representation constructed by the symbolic data, which is expressed as:

[0100] According to the complex signal representation and the symbol data, the symbol data can be further arranged into the form of the following signal model, that is, the signal model is constructed:

[0101] Y=csign(AS+W);

[0102] in, is the source signal matrix, is the white noise matrix, M r is the dimension that is rearranged in fast or slow time or space, is a frequency matrix, whose i-th column is a(h i ) and a(b i ) are respectively expressed as a(h i )=[1,exp(jh i ),…,exp(j(M r -1)h i )] T , a(b i )=[1,exp(jb i ),…,exp(j(M r -1)b i )] T .

[0103] Y can be obtained through the following four steps:

[0104] First, the single-bit signal y received by the mth array element is m (l,p) are arranged into a matrix where Y m The rows represent the sampled data in the fast time domain within a single pulse cycle, and the columns represent the sampled data in the slow time domain within multiple pulse cycles; then, Y m The pth row in the matrix is ​​rearranged in a smooth manner to form a matrix The size of the sliding window is M r ,Right now Each column comes from Y m The consecutive M in the pth row of r data; Next, P Rearrange into PM by block smoothing r +1 sub-matrix, where the rth sub-matrix is That is, it is achieved by dividing the continuous M r indivual Finally, the M array elements are received and rearranged to obtain M (PM r +1) subarray Arrange them into a row and get the matrix

[0105] After obtaining Y, calculate the covariance matrix R of Y Y :

[0106] R Y Perform eigenvalue decomposition, i.e. R Y =UΛU H , where Λ and U are matrices composed of eigenvalue diagonal matrices and their corresponding eigenvectors. By taking the smallest The eigenvector corresponding to the eigenvalue can be used to obtain the noise subspace

[0107] A two-dimensional MUSIC (Multiple signal classification algorithm) pseudo-spectral function is constructed based on the noise subspace, as shown below:

[0108] in, b k1 and h k2 are the sampling points in [0,π] and [-π,π] respectively, k1=1,…,K1, k2=1,…,K2, K1 and K2 are the number of sampling points in parameter b dimension and parameter h dimension respectively.

[0109] By searching the largest K spectral peaks of the pseudo-spectral function, K two-dimensional frequency pairs can be obtained, that is, the first two-dimensional frequency pair is obtained. By using the same method and the two-dimensional MUSIC algorithm, we can also find K two-dimensional frequency pairs, that is, we can get the second two-dimensional frequency pair The estimated results.

[0110] Furthermore, the step of obtaining the target information by using a target parameter calculation formula according to the estimation result includes:

[0111] constructing a first two-dimensional target parameter pair and a second two-dimensional target parameter pair;

[0112] Solving the first two-dimensional target parameter pair and the second two-dimensional target parameter pair according to the estimation result and the target parameter calculation formula to obtain preset target information;

[0113] According to the minimum Mahalanobis distance pairing principle, three-dimensional target parameter pairing is performed on the preset target information to obtain the target information.

[0114] Specifically, when solving the target information, first construct two two-dimensional target parameter pairs and That is, the first two-dimensional target parameter pair and the second two-dimensional target parameter pair. Use the target parameter calculation formula to solve the two two-dimensional target parameter pairs respectively and That is, the preset target information is obtained, and finally the speed dimension is and According to the pairing principle of minimum Mahalanobis distance (i.e. the i-th Should be with indivual is the same goal, i is a new variable), complete the pairing of three-dimensional target parameters, and obtain the target parameter pair That The average of the two speeds for successful pairing.

[0115] The target parameter calculation formula is as follows:

[0116] Among them, T1 is the pulse width of the transmitted LFMCW signal, T2 is the pulse period of the transmitted LFMCW signal, T3 is the pulse repetition period, T s is the sampling period of the single-bit ADC, B is the RF bandwidth, d is the spacing of the receiving antenna array, λ is the RF carrier wavelength, and c is the speed of light. Operation [x] ±π It is given by the following formula, where x represents a variable:

[0117] Furthermore, in the present application, the above-mentioned low-cost and lightweight single-bit multiplexed array radar signal processing method is implemented by the system structure shown in Figure 3. Specifically, as shown in Figure 3, the linear frequency modulation continuous wave signal transmitter is controlled by the signal transceiver control unit, and the linear frequency modulation continuous wave signal is radiated outward through the transmitting antenna; the signal transceiver control unit connects the receiving array antenna to the radio frequency multiplexer in a cyclic manner through the radio frequency multiplexer to obtain the array echo signal, and connects the connected array echo signal to the zero intermediate frequency receiver. After limiting, low-noise amplification, orthogonal demodulation and anti-aliasing filtering, mutually orthogonal I and Q zero intermediate frequency signals, namely the first zero intermediate frequency signal and the second zero intermediate frequency signal, are obtained. Then, the I and Q zero intermediate frequency signals are synchronously sampled by the single-bit analog-to-digital converter to obtain symbol data, and the symbol data is input into the signal processor to obtain target information.

[0118] Furthermore, in one embodiment of the present application, the number of antennas is set to M = 16, the carrier frequency is 77 GHz, the spacing between the receiving antennas is half the carrier wavelength, the RF bandwidth is B = 100 MHz, the pulse repetition period is T3 = 97.4026 μs, the number of pulses P = 12, the pulse width T1 = 6.0877 μs, the pulse period of the transmitted LFMCW signal is T2 = T1, the sampling frequency of the ADC is 10.9511 MHz, and the number of sampling points in a single cycle is L = 66. The parameter M of the above estimation algorithm is r = 8. Set the number of targets to 2, and their target parameter pairs (range, speed, azimuth) to (22 m, 8 m / s, -20°) and (37 m, 5 m / s, 8°), respectively. Set the SNR of both targets to -10 dB.

[0119] As shown in Figures 4 and 5, which are top-views of the pseudo-spectra in the slow-time-fast-time dimension (hb dimension) and the space-time-slow-time dimension (gh dimension), respectively, the amplitude of the pseudo-spectra is presented in dB, with the brightest point representing 0 dB. Two targets can be clearly seen in Figures 4 and 5. The two targets in the hb dimension can be searched as (2.3303, 1.5629) and (1.3994, 2.5064), and the two targets in the gh dimension are (1.5755, 0.6573) and (2.5064, -0.7453). According to the low-cost and lightweight single-bit multiplexing array radar signal processing method described in this application, the two estimated target parameter pairs can be obtained as (22.1975m, 7.9780m / s, -19.6919°) and (37.0404m, 4.9950m / s, 8.4254°). This result is very close to the actual target parameter pair, which demonstrates the correctness of the target acquisition principle of the present invention.

[0120] Then, as shown in Figures 6, 7, and 8, the root mean square error (RMSE) curves of parameter estimation using Monte Carlo numerical simulation are plotted. As shown in Figures 6, 7, and 8, the curves where the best performance of the inventive system in Figures 6, 7, and 8 is located are plotted using data obtained using the low-cost, lightweight single-bit multiplexing array radar signal processing method described in this application, and are given by the Cramer-Rao bound of the target parameter estimation of the transmitting system. The RMSE of the distance estimation is:

[0121] Among them, L s The number of Monte Carlo simulations is set to 1000 in this embodiment. is the estimated distance value of the kth simulation. The RMSE of speed or angle estimation can be replaced by the estimated value and the true value respectively. and r iget.

[0122] As shown in Figures 6, 7, and 8, for distance estimation, velocity estimation, and angle estimation, respectively, their corresponding optimal performance curves are less than 0.7 m, 0.11 m / s, and 0.5° when the SNR (Signal to Interference plus Noise Ratio) is -20 dB. This demonstrates that the present invention can achieve good distance, velocity, and angle estimation accuracy even with only a single receiver.

[0123] As the SNR increases, the RMSE of the target information obtained gradually approaches the optimal performance curve. In particular, when the SNR for the velocity and angle dimensions is greater than -10dB, the numerical verification results almost completely coincide with the optimal performance curve of the invented system, which indicates that the present invention can achieve better ranging and speed measurement performance.

[0124] As can be seen from the above, compared with the existing technology, the current traditional frequency modulated continuous wave array radar uses multiple receivers and multi-bit analog-to-digital converters to obtain echo signals from multiple antennas, resulting in a complex hardware system, large size, heavy load, and high power consumption, thereby limiting the application of radar in low-cost and small-load unmanned systems. The present invention uses a radio frequency multiplexer to obtain data on the echo signals of the receiving antenna array, making the system similar to the classic digital array radar, with a higher degree of freedom in signal processing, and can also achieve super-resolution estimation of the target angle; at the same time, in the present invention, the array echo signal is received by using a multiplexer. In this way, array echo signals are obtained and radar target parameters are estimated, thereby achieving better ranging and speed measurement performance. In addition, in the present invention, a multiplexer is used to receive the array echo signals, and the array echo signals are processed by the receiver. In order to ensure the data rate of the array echo signals, that is, the number of radar coverage range detections per minute, the pulse width of the radar signal is usually shortened, which is conducive to multiplexing of the zero intermediate frequency receiver and can greatly increase the number of receiver multiplexing times. Therefore, the present invention achieves a low-cost and lightweight design, making it more convenient to apply in low-cost and small-payload unmanned systems.

[0125] Exemplary devices

[0126] As shown in FIG9 , corresponding to the low-cost and lightweight single-bit multiplexing array radar signal processing method, an embodiment of the present invention further provides a low-cost and lightweight single-bit multiplexing array radar signal processing system. The low-cost and lightweight single-bit multiplexing array radar signal processing system includes:

[0127] A signal preprocessing module 91 is configured to obtain an array echo signal based on a radio frequency multiplexer, and preprocess the array echo signal to obtain a first zero intermediate frequency signal and a second zero intermediate frequency signal;

[0128] A symbol data acquisition module 92 is configured to perform single-bit synchronous sampling on the first zero-IF signal and the second zero-IF signal to obtain symbol data;

[0129] The target information generating module 93 is configured to estimate intermediate parameters according to the symbol data, and calculate target information according to the estimation results of the intermediate parameters.

[0130] It should be noted that the specific structure and implementation of the low-cost, lightweight single-bit multiplexing array radar signal processing system and its various modules or units can refer to the corresponding description in the method embodiment and will not be repeated here.

[0131] It should be noted that the division method of each module of the low-cost and lightweight single-bit multiplexing array radar signal processing system is not unique and is not specifically limited here.

[0132] Based on the above embodiment, the present invention further provides a terminal, the functional block diagram of which can be shown in FIG10 . The terminal includes a processor 10, a memory 20, a network interface, and a display 30 connected via a system bus. In one embodiment, when the processor 10 executes a low-cost, lightweight, single-bit multiplexed array radar signal processing program 40 stored in the memory 20, the following steps are implemented:

[0133] Acquiring an array echo signal based on a radio frequency multiplexer, and preprocessing the array echo signal to obtain a first zero intermediate frequency signal and a second zero intermediate frequency signal;

[0134] Performing single-bit synchronous sampling on the first zero-IF signal and the second zero-IF signal to obtain symbol data;

[0135] According to the symbol data, intermediate parameters are estimated, and target information is calculated based on the estimation results of the intermediate parameters.

[0136] Optionally, the step of acquiring an array echo signal based on a radio frequency multiplexer and preprocessing the array echo signal to obtain a first zero intermediate frequency signal and a second zero intermediate frequency signal includes:

[0137] All receiving antennas are sequentially connected to a zero intermediate frequency receiver based on a radio frequency multiplexer, and the zero intermediate frequency receiver receives an array echo signal;

[0138] The array echo signal is preprocessed to obtain a first zero intermediate frequency signal and a second zero intermediate frequency signal that are orthogonal to each other, wherein the preprocessing includes limiting, low noise amplification, orthogonal demodulation and anti-aliasing filtering operations.

[0139] Optionally, the step of performing single-bit synchronous sampling on the first zero-IF signal and the second zero-IF signal to obtain symbol data includes:

[0140] Performing single-bit synchronous sampling on the first zero-intermediate frequency signal and the second zero-intermediate frequency signal based on a single-bit analog-to-digital converter, and extracting sign bits of the first zero-intermediate frequency signal and the second zero-intermediate frequency signal;

[0141] Sign data is generated according to the sign bit.

[0142] Optionally, the step of estimating intermediate parameters according to the symbol data, and calculating target information according to the estimation results of the intermediate parameters includes:

[0143] estimating the intermediate parameter according to the symbol data and a sampling frequency estimation algorithm to obtain the estimation result;

[0144] According to the estimation result, the target information is obtained using a target parameter calculation formula.

[0145] Optionally, the step of estimating the intermediate parameter according to the symbol data and a sampling frequency estimation algorithm to obtain the estimation result includes:

[0146] Set the intermediate parameters according to the preset intermediate parameter setting formula;

[0147] constructing a first two-dimensional frequency pair and a second two-dimensional frequency pair according to the intermediate parameters;

[0148] The first two-dimensional frequency pair and the second two-dimensional frequency pair are estimated according to the symbol data to obtain the estimation result.

[0149] Optionally, the step of estimating the first two-dimensional frequency pair and the second two-dimensional frequency pair according to the symbol data to obtain the estimation result includes:

[0150] Acquire a complex signal representation constructed from the symbolic data, and construct a signal model based on the symbolic data and the complex signal representation;

[0151] Calculating a covariance matrix according to the signal model, and obtaining a noise subspace according to the covariance matrix;

[0152] The estimation result is generated according to the noise subspace.

[0153] Optionally, the step of obtaining the target information by using a target parameter calculation formula according to the estimation result includes:

[0154] constructing a first two-dimensional target parameter pair and a second two-dimensional target parameter pair;

[0155] Solving the first two-dimensional target parameter pair and the second two-dimensional target parameter pair according to the estimation result and the target parameter calculation formula to obtain preset target information;

[0156] According to the minimum Mahalanobis distance pairing principle, three-dimensional target parameter pairing is performed on the preset target information to obtain the target information.

[0157] The terminal's processor is used to provide computing and control capabilities. The terminal's memory includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a low-cost, lightweight single-bit multiplexed array radar signal processing program. The internal memory provides an environment for the operation of the operating system and the low-cost, lightweight single-bit multiplexed array radar signal processing program in the non-volatile storage medium. The terminal's network interface is used to communicate with external terminals via a network connection. When executed by the processor, the low-cost, lightweight single-bit multiplexed array radar signal processing program implements the steps of any one of the described low-cost, lightweight single-bit multiplexed array radar signal processing methods. The terminal's display screen may be a liquid crystal display or an electronic ink display screen.

[0158] Those skilled in the art will understand that the principle block diagram shown in Figure 10 is only a block diagram of a partial structure related to the solution of the present invention, and does not constitute a limitation on the terminal to which the solution of the present invention is applied. The specific terminal may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0159] In one embodiment, a terminal is provided, comprising a memory, a processor, and a low-cost, lightweight single-bit multiplexed array radar signal processing program stored in the memory and executable on the processor. When executed by the processor, the low-cost, lightweight single-bit multiplexed array radar signal processing program implements the steps of any one of the low-cost, lightweight single-bit multiplexed array radar signal processing methods provided in the embodiments of the present invention.

[0160] An embodiment of the present invention further provides a computer-readable storage medium, on which is stored a low-cost, lightweight, single-bit multiplexed array radar signal processing program. When the low-cost, lightweight, single-bit multiplexed array radar signal processing program is executed by a processor, the steps of any one of the low-cost, lightweight, single-bit multiplexed array radar signal processing methods provided in the embodiments of the present invention are implemented.

[0161] It should be understood that the sequence numbers of the steps in the embodiment do not imply a specific order of execution; the order of execution of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0162] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the functional units and modules is used as an example for illustration. In actual applications, the functional distribution can be 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 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 the present invention. The specific working process of the units and modules in the device can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0163] In the 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 descriptions of other embodiments.

[0164] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present invention.

[0165] In the embodiments provided herein, it should be understood that the disclosed systems / terminal devices and methods may be implemented in other ways. For example, the system / terminal device embodiments described above are merely illustrative. For example, the division of modules or units is merely a logical functional division. In actual implementation, other division methods may be used, such as combining or integrating multiple units or components into another system, or omitting or not implementing certain features.

[0166] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the process in the embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and when the computer program is executed by the processor, it can implement the steps of the various method embodiments. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device that can carry the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium, etc.

[0167] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, it should be understood by those skilled in the art that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the scope of protection of the present invention.

Claims

1. A low-cost and lightweight single-bit multiplexing array radar signal processing method, characterized in that: The low-cost and lightweight single-bit multiplexing array radar signal processing method includes: Acquiring an array echo signal based on a radio frequency multiplexer, and preprocessing the array echo signal to obtain a first zero intermediate frequency signal and a second zero intermediate frequency signal; Performing single-bit synchronous sampling on the first zero-IF signal and the second zero-IF signal to obtain symbol data; According to the symbol data, intermediate parameters are estimated, and target information is calculated based on the estimation results of the intermediate parameters.

2. The low-cost and lightweight single-bit multiplexing array radar signal processing method according to claim 1, characterized in that: The steps of acquiring an array echo signal based on a radio frequency multiplexer and preprocessing the array echo signal to obtain a first zero intermediate frequency signal and a second zero intermediate frequency signal include: All receiving antennas are sequentially connected to a zero intermediate frequency receiver based on a radio frequency multiplexer, and the zero intermediate frequency receiver receives an array echo signal; The array echo signal is preprocessed to obtain a first zero intermediate frequency signal and a second zero intermediate frequency signal that are orthogonal to each other, wherein the preprocessing includes limiting, low noise amplification, orthogonal demodulation and anti-aliasing filtering operations.

3. The low-cost and lightweight single-bit multiplexing array radar signal processing method according to claim 1, characterized in that: The step of performing single-bit synchronous sampling on the first zero-IF signal and the second zero-IF signal to obtain symbol data includes: Performing single-bit synchronous sampling on the first zero-intermediate frequency signal and the second zero-intermediate frequency signal based on a single-bit analog-to-digital converter, and extracting sign bits of the first zero-intermediate frequency signal and the second zero-intermediate frequency signal; Sign data is generated according to the sign bit.

4. The low-cost and lightweight single-bit multiplexing array radar signal processing method according to claim 1, characterized in that: The step of estimating intermediate parameters according to the symbol data, and calculating target information according to the estimation results of the intermediate parameters includes: estimating the intermediate parameter according to the symbol data and a sampling frequency estimation algorithm to obtain the estimation result; According to the estimation result, the target information is obtained using a target parameter calculation formula.

5. The low-cost and lightweight single-bit multiplexing array radar signal processing method according to claim 4, characterized in that: The step of estimating the intermediate parameter according to the symbol data and the sampling frequency estimation algorithm to obtain the estimation result comprises: Set the intermediate parameters according to the preset intermediate parameter setting formula; constructing a first two-dimensional frequency pair and a second two-dimensional frequency pair according to the intermediate parameters; The first two-dimensional frequency pair and the second two-dimensional frequency pair are estimated according to the symbol data to obtain the estimation result.

6. The low-cost and lightweight single-bit multiplexing array radar signal processing method according to claim 5, characterized in that: The step of estimating the first two-dimensional frequency pair and the second two-dimensional frequency pair according to the symbol data to obtain the estimation result comprises: Acquire a complex signal representation constructed from the symbolic data, and construct a signal model based on the symbolic data and the complex signal representation; Calculating a covariance matrix according to the signal model, and obtaining a noise subspace according to the covariance matrix; The estimation result is generated according to the noise subspace.

7. The low-cost and lightweight single-bit multiplexing array radar signal processing method according to claim 4, characterized in that: The step of obtaining the target information by using a target parameter calculation formula according to the estimation result includes: constructing a first two-dimensional target parameter pair and a second two-dimensional target parameter pair; Solving the first two-dimensional target parameter pair and the second two-dimensional target parameter pair according to the estimation result and the target parameter calculation formula to obtain preset target information; According to the minimum Mahalanobis distance pairing principle, three-dimensional target parameter pairing is performed on the preset target information to obtain the target information.

8. A low-cost, lightweight, single-bit multiplexing array radar signal processing system, characterized in that: The low-cost and lightweight single-bit multiplexing array radar signal processing system includes: a signal preprocessing module, configured to obtain an array echo signal based on a radio frequency multiplexer, and preprocess the array echo signal to obtain a first zero intermediate frequency signal and a second zero intermediate frequency signal; A symbol data acquisition module, configured to perform single-bit synchronous sampling on the first zero-IF signal and the second zero-IF signal to obtain symbol data; The target information generating module is used to estimate the intermediate parameters according to the symbol data, and calculate the target information according to the estimation results of the intermediate parameters.

9. A terminal, characterized in that: The terminal includes a memory, a processor, and a low-cost, lightweight single-bit multiplexed array radar signal processing program stored in the memory and executable on the processor. When the low-cost, lightweight single-bit multiplexed array radar signal processing program is executed by the processor, the low-cost, lightweight single-bit multiplexed array radar signal processing program implements the steps of the low-cost, lightweight single-bit multiplexed array radar signal processing method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a low-cost, lightweight, single-bit multiplexed array radar signal processing program. When the low-cost, lightweight, single-bit multiplexed array radar signal processing program is executed by a processor, the steps of the low-cost, lightweight, single-bit multiplexed array radar signal processing method according to any one of claims 1 to 7 are implemented.

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