Target DOA estimation method and system based on MIMO radar co-prime array

Abstract

The invention relates to a target DOA estimation method and system based on an MIMO radar co-prime array. The method comprises the following steps: acquiring multiple groups of first arrays with uniform azimuth array element spacing, wherein the azimuth array element spacing of each group of first arrays is relatively prime pairwise; performing pitching position completion on each group of first arrays to obtain a second array; for an array element consistent with the original array element in position in the second linear array, retaining a corresponding array element complex signal, and for an array element inconsistent with the original array element in position, performing phase compensation based on a pitch array element spacing difference and a pitch angle to obtain a new array element complex signal; dOA estimation is carried out on each group of third arrays, and an angle value is selected from the angle set and combined to form an angle subset; performing difference value elimination processing on the angle subset, and calculating a first matching degree based on a constructed cost function; and determining a target angle estimation value based on the angle subset of which the matching degree exceeds a set first matching degree threshold value. The method can greatly reduce the generation probability of false alarms.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of intelligent driving and the field of array signal technology, in particular to a target DOA (Direction of Arrival) estimation method and system based on a MIMO (Multiple Input Multiple Output) radar array. BACKGROUND

[0002] As one of the core sensors of intelligent driving, the millimeter wave radar has high ranging, speed and angle measurement performance, and can better meet the needs of vehicle application scenarios. Using a MIMO radar sparse array can effectively increase the antenna aperture and improve the angle resolution of the radar. However, the sparse array can cause high grating lobes and false alarms, thereby affecting the normal driving of the vehicle in the intelligent driving mode, and even causing traffic accidents.

[0003] Currently, there are two main categories of methods for measuring the angle of a target based on a MIMO radar sparse array: More methods directly use digital beam forming (DBF) or interpolation zero padding FFT (Fast Fourier Transform) to calculate the target angle. However, such methods cannot suppress grating lobes and are prone to false alarms; A few methods use deterministic maximum likelihood (DML) or multiple signal classification (MUSIC) super-resolution algorithms to calculate the target angle. However, such methods require a large amount of computing power (more than 10 times the computing power of the DBF algorithm), and in the case of a cost-limited radar processor, only a small number of screened point clouds are processed using super-resolution algorithms to solve their angles while ensuring real-time performance and improving some performance. SUMMARY

[0004] Therefore, the present application provides a target DOA estimation method and system based on a MIMO radar array, which can greatly reduce the probability of false alarm, improve the accuracy of DOA angle measurement, and improve the accuracy of target detection and recognition, thereby ensuring the safety of vehicle driving.

[0005] To solve the above technical problems, the present application provides a target DOA estimation method based on a MIMO radar array, comprising: Based on the MIMO sparse array arranged in sequence according to the azimuth dimension spacing, a plurality of groups of first arrays with uniform azimuth element spacing are obtained; wherein the azimuth element spacings of each group of the first arrays are pairwise coprime; Based on the original element position of the MIMO sparse array, the elevation position of each group of the first array is completed to obtain a second array including azimuth element spacing and elevation element spacing; The element reconstruction is performed on each group of the second array to obtain a third array; wherein for the elements in the second linear array consistent with the original element position, the corresponding element complex signal is retained, and for the elements inconsistent with the original element position, phase compensation is performed based on the elevation element spacing difference and the elevation angle to obtain a new element complex signal, so that the elevation element spacing in the second linear array remains consistent; The DOA estimation is performed on each group of the third array to obtain a corresponding angle set, and an angle value is selected from each of the angle sets and combined to form an angle subset; The angle subset is subjected to a difference value processing, and a first matching degree is calculated based on a constructed cost function; Based on the angle subset with the first matching degree exceeding a set first matching degree threshold, a target angle estimation value is determined.

[0006] In an embodiment of the present application, the phase compensation based on the elevation element spacing difference and the elevation angle to obtain a new element complex signal comprises: calculating the new element complex signal by using the following formula: New_IQ , Wherein, Amp is the modulus value of the complex signal; is the wavelength of the incident signal; D and are the elevation element spacing difference and the elevation angle, respectively; is the element phase; is the imaginary unit.

[0007] In an embodiment of the present application, the DOA estimation is performed on each group of the third array to obtain a corresponding angle set, comprising: The DOA estimation is performed on each group of the third array by using a DBF included angle measurement algorithm.

[0008] In an embodiment of the present application, further comprising: The DOA estimation is performed on each group of the third array by using a DBF included angle measurement algorithm to obtain a beam pattern; The local peak angle in the beam pattern is screened to retain the angle greater than a set signal intensity threshold.

[0009] In an embodiment of the present application, the angle subset is subjected to a rejection difference value processing, which comprises: The difference value between any two angle values is calculated, and if the difference value exceeds a set angle threshold value, the angle subset is rejected.

[0010] In an embodiment of the present application, the cost function is as follows: , Wherein, is the first matching degree; is a factor coefficient, and the sum of the coefficients is 1: is designed as a fixed value or a floating value according to data statistical analysis; is the mth angle value output by the first third array; is the nth angle value output by the second third array; is the kth angle value output by the third third array; is the jth angle value output by the ith third array.

[0011] In an embodiment of the present application, based on the angle subset in which the first matching degree exceeds a set first matching degree threshold value, a target angle estimation value is determined, which comprises: The multiple angle values in the angle subset in which the first matching degree exceeds the set first matching degree threshold value are subjected to statistical calculation, and the average value is obtained to obtain a first angle value set; A second angle value set is obtained through angle measurement algorithm detection of the MIMO sparse array; The respective angle values in the first angle value set and the second angle value set are subjected to two-by-two calculation of a second matching degree; If the second matching degree is higher than a set second matching degree threshold value, it is considered that the target angle matching check is successful, and the angle in the second angle value set that passes the check is finally output, and the second matching degree is synchronously output as an evaluation index of the angle for downstream adaptation.

[0012] In an embodiment of the present application, the second matching degree is calculated as follows: , Wherein, is a coefficient factor; is an angle value in the first angle value set; is an angle value in the second angle value set.

[0013] The present application also provides a target DOA estimation system based on a MIMO radar coprime array, which comprises: The first array forming module is configured to obtain a plurality of first arrays with uniform azimuth element spacing based on a MIMO sparse array arranged in sequence according to azimuth dimension spacing. The second array forming module is configured to complete the elevation position of each of the first arrays based on the original element position of the MIMO sparse array to obtain a second array including azimuth element spacing and elevation element spacing. The third array forming module is configured to reconstruct the elements of each of the second arrays to obtain a third array. The angle measurement processing module is configured to perform DOA estimation on each of the third arrays to obtain a corresponding angle set, and select an angle value from each of the angle sets and combine the angle values to form an angle subset. The matching module is configured to perform a difference value elimination process on the angle subset and calculate a first matching degree based on a constructed cost function. The target angle estimation value calculation module is configured to determine a target angle estimation value based on the angle subset with the first matching degree exceeding a set first matching degree threshold.

[0014] The above technical solution of the present application has the following advantages compared with the prior art: The target DOA estimation method and system based on the MIMO radar coprime array can greatly reduce the probability of false alarm, improve the DOA angle measurement precision and accuracy, improve the accuracy of target detection and recognition, and is beneficial to ensuring the driving safety of the vehicle, and is applicable to 3D radar or 4D radar. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to make the content of the present application more easily understood, the present application will be further described in detail below according to specific embodiments of the present application and in conjunction with the accompanying drawings.

[0016] Figure 1 is a flowchart of the target DOA estimation method based on the MIMO radar coprime array in embodiment 1 of the present application.

[0017] Figure 2 is a DOA estimation beam diagram (horizontal coordinate: angle; vertical coordinate: energy normalization) in embodiment 2 of the present application. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0019] In this invention, when directions (up, down, left, right, front, and back) are described, it is only for the convenience of describing the technical solution of this invention, and does not indicate or imply that the technical features referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0020] In this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," "exceeding," etc., are understood to exclude the stated number; "above," "below," "within," etc., are understood to include the stated number. In the description of this invention, the terms "first" and "second" are used only to distinguish technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0021] In this invention, unless otherwise explicitly defined, the terms "setting," "installing," and "connecting" should be interpreted broadly. For example, they can refer to a direct connection or an indirect connection through an intermediate medium; a fixed connection, a detachable connection, or an integrally formed connection; a mechanical connection, an electrical connection, or a connection capable of mutual communication; or the internal connection of two components or the interaction between two components. Those skilled in the art can reasonably determine the specific meaning of the above terms in this invention based on the specific content of the technical solution.

[0022] Example 1 Reference Figure 1 As shown in this embodiment, a target DOA estimation method based on a MIMO radar coprime array includes: S1. Based on a MIMO sparse array arranged in order of azimuth dimension spacing of array elements, obtain multiple sets of first arrays with uniform azimuth element spacing; wherein, the azimuth element spacing of each set of first arrays is pairwise coprime; it should be noted that coprime arrays refer to two sets of uniform linear arrays ULA (Uniform Linear Array), where the spacing M of uniform linear array L1 and the spacing N of uniform linear array L2 are coprime numbers, then uniform linear array L1 and uniform linear array L2 are coprime arrays. S2. Based on the original array element positions of the MIMO sparse array, the elevation positions of each group of the first array are completed to obtain a second array including the azimuth element spacing and the elevation element spacing. S3, reconstructing array elements of each group of the second array to obtain a third array; wherein for an array element in the second linear array consistent with the original array element position, the corresponding array element complex signal is retained, and for an array element not consistent with the original array element position, a new array element complex signal is obtained through phase compensation based on the difference in elevation array element spacing and the elevation angle, so that the elevation array element spacing in the second linear array remains consistent; S4, performing DOA estimation on each group of the third array to obtain a corresponding angle set, respectively selecting an angle value from each of the angle sets and merging to form an angle subset; S5, performing a difference value elimination process on the angle subset, and calculating a first matching degree based on a constructed cost function; S6, determining a target angle estimation value based on the angle subset whose first matching degree exceeds a set first matching degree threshold.

[0023] Specifically, the phase compensation based on the difference in elevation array element spacing and the elevation angle to obtain a new array element complex signal includes: calculating a new array element complex signal using the following formula: New_IQ , Wherein, Amp is the modulus value of the complex signal; is the wavelength of the incident signal; D and are the difference in elevation array element spacing and the elevation angle, respectively; is the array element phase; is the imaginary unit.

[0024] Specifically, performing DOA estimation on each group of the third array to obtain a corresponding angle set includes: using a DBF included angle estimation algorithm to perform DOA estimation on each group of the third array to obtain a beam pattern; screening the local peak angle in the beam pattern to retain angles greater than a set signal intensity threshold. For example, 80% of the maximum value is used as the threshold for screening.

[0025] It should be noted that DBF (Digital Beam Forming) is an angle measurement algorithm; by weighting and superimposing the signals received by multiple array elements, a directional beam is synthesized; each beam direction corresponds to a signal intensity value, and all directions are combined to form a beam pattern.

[0026] Specifically, performing a difference value elimination process on the angle subset includes: performing pairwise difference value calculation on each angle value in the angle subset, and if the difference between any two angle values exceeds a set angle threshold, the angle subset is eliminated.

[0027] Specifically, the cost function is as follows: wherein, is the first matching degree; is a factor coefficient, the sum of the coefficients and is 1: , is designed to be a fixed value or a floating value according to data statistical analysis; is the mth angle value output by the first third array; is the nth angle value output by the second third array; is the kth angle value output by the third third array; is the jth angle value output by the ith third array.

[0028] Specifically, based on the angle subset whose first matching degree exceeds the set first matching degree threshold, the target angle estimation value is determined, comprising: statistical calculation is performed on the multiple angle values in the angle subset whose first matching degree exceeds the set first matching degree threshold, and a first angle value set is obtained after averaging; a second angle value set is obtained after the MIMO sparse array is detected by the angle measurement algorithm; second matching degrees are calculated by pairwise calculation of the respective angle values in the first angle value set and the second angle value set; if the second matching degree is higher than the set second matching degree threshold, it is considered that the target angle matching check is successful; the second angle value set in which the check is successful is finally output, and the second matching degree is synchronously output as the evaluation index of the angle for downstream adaptation.

[0029] Specifically, the second matching degree is calculated as follows: wherein, is a coefficient factor; is an angle value in the first angle value set; is an angle value in the second angle value set.

[0030] Through the above method, based on the MIMO sparse array, a coprime array is found therein, DOA estimation is performed on one or more groups of coprime arrays respectively, and then the detected angles are matched and statistically analyzed to finally obtain the target angle. The present application can greatly reduce the probability of false alarm, improve the DOA angle measurement precision and accuracy, improve the accuracy of target detection and recognition, and is conducive to ensuring the driving safety of the vehicle.

[0031] Embodiment 2 ​​This embodiment takes 4D radar MIMO sparse array as an example. The target DOA estimation method based on MIMO radar coprime array includes the following steps:

[0032] Step S1: find the coprime array.

[0033] S11, sequentially arrange the MIMO sparse array, Neglecting different elevation positions, sequentially arrange the MIMO sparse array according to the spacing of the azimuth dimension of the array elements, and the array can be obtained:

[0034] A={0,5,7,8,12,13,15,18,19,21,23,25,26,30}, the spacing is an integer multiple of half the wavelength of the incident signal.

[0035] S12, find the uniform linear array among them, and multiple results can be obtained, as follows: B1={5,12,19,26}, the spacing is 7; B2={7,13,19,25}, the spacing is 6; B3={8,13,18,23}, the spacing is 5; S13, find the coprime array according to the spacing of the multiple uniform linear arrays. Since the spacing of the three uniform linear arrays is coprime, the combination of the uniform linear arrays B1, B2 and B3 is a coprime array.

[0036] Step S2: array element reconstruction of the coprime array.

[0037] S21, combine the layout of the original MIMO sparse array to perfect the elevation position of the uniform linear array. The three uniform arrays are updated as follows according to (azimuth element spacing, elevation element spacing):

[0038] , , , S22, array element reconstruction and corresponding complex signal calculation.

[0039] S221, if the array element positions of the three uniform linear arrays are consistent with the array element positions of the original MIMO sparse array, the corresponding array element complex signals are retained; S222, if not, perform array element reconstruction to make the elevation positions consistent, combine the array element spacing difference D and the elevation angle of the elevation position, and perform phase compensation to obtain the complex signal New_IQ of the new array element.

[0040] Take the fourth array element (26,-3) of B1 whose complex signal is as an example, the following is described: The calculation formula of the complex signal New_IQ of the new element (26, 0) is as follows: New_IQ , Wherein, Amp is the modulus value of the complex signal; is the wavelength of the incident signal; D and are the difference between the elevation element spacing and the elevation angle, respectively; is the element phase; is the imaginary unit.

[0041] S23, obtain the coprime array and the corresponding complex signal update, After the reconstruction and complex signal calculation of the three groups of uniform linear arrays B1, B2 and B3, the coprime array is obtained, and the specific arrangement is as follows:

[0042] , , , Step S3: DOA estimation.

[0043] Take the DBF angle measurement algorithm as an example for illustration.

[0044] S31, adopt the DBF angle measurement algorithm to obtain the DOA estimation beam pattern as shown in Figure 2

[0045] S32, angle retrieval.

[0046] Set a suitable threshold to filter the angles, for example, take 80% of the maximum value as the threshold to filter, and the three ULAs will retrieve multiple angles, and the angle set is represented as: ULA1_angle = , m angle values, ULA2_angle = , n angle values, ULA3_angle = , k angle values.

[0047] S33, matching.

[0048] Match the multiple angle values in the angle set, and take one value from each of the three angle sets to merge into an angle subset A={ }.

[0049] S331, eliminate the difference value.

[0050] Calculate the difference value between the two numbers in the angle subset A, and if there is a large difference (exceeding the set angle threshold), the angle subset A will be directly eliminated.

[0051] ​S332, construct a cost function.

[0052] If three values in the angle subset A are close (within a set angle threshold), calculate the first matching degree by constructing a cost function, as follows: , wherein, is the first matching degree; is a factor coefficient, which is designed as a fixed value or a floating value after data statistical analysis; is the mth angle value output by the first third array; is the nth angle value output by the second third array; is the kth angle value output by the third third array.

[0053] S333, angle screening.

[0054] For the angle subset A whose matching degree cost1 exceeds the first matching degree threshold, it is considered to pass, and the angle values in the angle subset A will be used for statistical analysis.

[0055] S34, angle calculation.

[0056] For the three angle values in the angle subset A, statistical analysis is performed, and the angle value set X is obtained by taking the average.

[0057] S35, angle verification.

[0058] Based on the DBF angle measurement algorithm of the original MIMO sparse array, multiple angle sets Y are detected, and the angle value sets X obtained by the multiple groups of coprime arrays are matched and verified to further reduce the probability of false alarm angles. Specifically as follows:

[0059] S1, calculate the second matching degree between the angle values in the angle set X and the angle set Y, two by two : , wherein, is a coefficient factor; is the angle value of the first angle value set; is the angle value in the first angle value set.

[0060] S2, screen out those with a matching degree higher than the set second matching degree threshold, which is considered to be a successful target angle matching verification; S3, for the matching degree cost2 exceeding the second matching degree threshold, the successfully verified angle in the set Y is finally output, and the matching degree cost2 is output as the evaluation index of the angle, which is used for downstream adaptation.

[0061] Embodiment 3 Based on the same inventive concept, the embodiment provides a target DOA estimation system based on MIMO radar coprime array, which has similar problem solving principle as the target DOA estimation method based on MIMO radar coprime array, and the repeated parts will not be described herein.

[0062] The embodiment provides a target DOA estimation system based on MIMO radar coprime array, which comprises: A first array forming module is configured to obtain a plurality of first arrays with uniform azimuth element spacing based on a MIMO sparse array arranged in sequence according to azimuth dimension spacing; wherein the azimuth element spacing of each of the first arrays is coprime with each other. A second array forming module is configured to complete the elevation position of each of the first arrays based on the original element position of the MIMO sparse array, to obtain a second array comprising azimuth element spacing and elevation element spacing. A third array forming module is configured to reconstruct the element of each of the second arrays to obtain a third array; wherein for the element in the second linear array consistent with the original element position, the corresponding element complex signal is retained, and for the element not consistent with the original element position, the phase compensation is performed based on the elevation element spacing difference and the elevation angle to obtain a new element complex signal, so that the elevation element spacing in the second linear array remains consistent. An angle measurement processing module is configured to perform DOA estimation on each of the third arrays to obtain a corresponding angle set, and to select an angle value from each of the angle sets and combine to form an angle subset. A matching module is configured to perform difference value processing on the angle subset, and to calculate a first matching degree based on a constructed cost function. A target angle estimation value calculation module is configured to determine a target angle estimation value based on the angle subset with the first matching degree exceeding a set first matching degree threshold.

[0063] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer usable program code.

[0064] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flow or blocks Figure 1 means for functionally implementing the steps in one or more flow or blocks

[0065] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flow or blocks Figure 1 means for functionally implementing the steps in one or more flow or blocks

[0066] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flow or blocks Figure 1 means for functionally implementing the steps in one or more flow or blocks

[0067] Finally, it should be noted that the above detailed description is merely illustrative of the technical solutions of the present application and is not limiting, and although the present application has been described in detail with reference to examples, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application, and all should be covered in the scope of the claims of the present application.

Claims

1. A method for target DOA estimation based on MIMO radar coprime array, characterized in that, The method comprises the following steps: Based on the MIMO sparse array arranged in order according to the azimuth dimension spacing, a plurality of groups of first arrays with uniform azimuth element spacing are obtained; wherein the azimuth element spacings of each group of first arrays are pairwise relatively prime; Based on the original element position of the MIMO sparse array, the elevation position of each group of first arrays is completed to obtain a second array including azimuth element spacing and elevation element spacing; The element reconstruction is performed on each group of second arrays to obtain a third array; wherein for the elements in the second linear array consistent with the original element position, the corresponding element complex signal is retained, and for the elements not consistent with the original element position, phase compensation is performed based on the elevation element spacing difference and the elevation angle to obtain a new element complex signal, so that the elevation element spacing in the second linear array remains consistent; DOA estimation is performed on each group of third arrays to obtain a corresponding angle set, and an angle value is selected from each angle set and combined to form an angle subset; The angle subset is processed by eliminating the difference value, and a first matching degree is calculated based on the constructed cost function; Based on the angle subset with the first matching degree exceeding the set first matching degree threshold, a target angle estimation value is determined.

2. The method of claim 1, wherein, The phase compensation based on the elevation element spacing difference and the elevation angle to obtain a new element complex signal comprises: calculating the new element complex signal by using the following formula: New_IQ , wherein, Amp is the modulus of the complex signal; is the wavelength of the incident signal; D and are the difference of the elevation element spacing and the elevation angle, respectively; is the element phase; is the imaginary unit.

3. The method of claim 1, wherein, The DOA estimation of each group of third arrays to obtain a corresponding angle set comprises: The DOA estimation of each group of third arrays is performed by using the angle measurement algorithm including DBF to obtain a beam pattern.

4. The method of claim 3, wherein, Further comprising: The DOA estimation of each group of third arrays is performed by using the angle measurement algorithm including DBF to obtain a beam pattern. The local peak angle in the beam pattern is screened, and the angle greater than the set signal intensity threshold is retained.

5. The method of claim 1, wherein, The angle subset is processed by eliminating the difference value, comprising: The difference value between each angle value in the angle subset is calculated, and if the difference value between any two angle values exceeds the set angle threshold, the angle subset is eliminated.

6. The method of claim 1, wherein, The formula of the cost function is as follows: ， Wherein, 1 is the first matching degree; is a factor coefficient, the coefficient and is 1: , according to the data statistical analysis and design into a fixed value or is a floating change value; is the mth angle value output by the first third array; is the nth angle value output by the second third array; is the kth angle value output by the third third array; is the jth angle value output by the ith third array.

7. The method of claim 1, wherein, Based on the angle subset with the first matching degree exceeding the set first matching degree threshold, a target angle estimation value is determined, comprising: Statistical calculation is performed on the plurality of angle values in the angle subset with the first matching degree exceeding the set first matching degree threshold, and the average value is obtained to obtain a first angle value set; After the MIMO sparse array is detected by the angle measurement algorithm, a second angle value set is obtained; The second matching degree is calculated by pairwise calculation of the angle values in the first angle value set and the second angle value set; If the second matching degree is higher than the set second matching degree threshold, it is considered that the target angle matching check is successful; finally, the angle in the second angle value set that passes the check is output, and the second matching degree is output as the evaluation index of the angle for downstream adaptation.

8. The method of claim 7, wherein, The second matching degree is calculated as follows: ， wherein is a coefficient factor; is an angle value of the first set of angle values; is an angle value of the second set of angle values. 9.A target DOA estimation system based on MIMO radar mutually prime array, characterized in that, Comprising: The first array forming module is configured to obtain a plurality of first arrays with uniform azimuth element spacing based on the MIMO sparse array arranged in sequence according to the azimuth dimension spacing; wherein the azimuth element spacing of each of the first arrays is relatively prime to each other; The second array forming module is configured to complete the elevation position of each of the first arrays based on the original element position of the MIMO sparse array to obtain a second array including azimuth element spacing and elevation element spacing; The third array forming module is configured to reconstruct the element of each of the second arrays to obtain a third array; wherein for the element consistent with the original element position in the second linear array, the corresponding element complex signal is retained, and for the element inconsistent with the original element position, the phase compensation is performed based on the elevation element spacing difference and the elevation angle to obtain a new element complex signal, so that the elevation element spacing in the second linear array remains consistent; The angle measurement processing module is configured to perform DOA estimation on each of the third arrays to obtain a corresponding angle set, and to select an angle value from each of the angle sets and combine to form an angle subset; The matching module is configured to perform a difference value processing on the angle subset, and to calculate a first matching degree based on a constructed cost function; The target angle estimation value calculation module is configured to determine a target angle estimation value based on the angle subset with the first matching degree exceeding a set first matching degree threshold.

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