A constant false alarm rate (CFAR) detection method, apparatus, equipment, and storage medium

Abstract

This invention discloses a constant false alarm rate (CFAR) detection method, apparatus, device, and storage medium, comprising: processing the raw signal acquired by a millimeter-wave radar to obtain a range-Doppler spectrum (RDM) matrix of the acquisition environment of the millimeter-wave radar; determining the window geometry corresponding to the measured element in the RDM, and forming a reference window region and a guard window region with the window geometry relative to the measured element, wherein the measured element is a matrix element in the RDM matrix; determining the CFAR detection threshold of the measured element based on the element values ​​of the matrix elements contained in the reference window region and the guard window region; and determining the CFAR detection result of the measured element based on the CFAR detection threshold. The above technical solution reduces the computational load of CFAR detection, reduces the interference of noise and clutter on radar detection, ensures the accuracy of CFAR detection, and improves the performance of radar detection.

Description

Technical Field

[0001] This invention relates to the field of millimeter-wave radar technology, and in particular to a constant false alarm rate (CFAR) detection method, apparatus, device, and storage medium. Background Technology

[0002] With the continuous development and progress of electronic technology, radar detection technology has made significant progress. Constant False Alarm Rate (CFAR) technology is a technique used by radar systems to distinguish between the signal and noise output by the receiver while maintaining a constant false alarm probability to determine the presence of a target signal.

[0003] Currently, this technology has been widely applied in various systems such as detection and early warning, target search, target tracking, and target imaging. However, when faced with noise generated by various environments, such as weather, terrain, and electromagnetic interference, using a fixed threshold for target detection will produce certain false alarms. When the clutter background fluctuates, it is not possible to effectively suppress radar noise, resulting in residual clutter in the acquired signal, which seriously affects radar performance and fails to achieve good radar detection results. Summary of the Invention

[0004] This invention provides a constant false alarm rate (CFAR) detection method, apparatus, device, and storage medium, which can efficiently determine whether a target signal exists in the raw signal acquired by radar under various background noise and environmental clutter conditions, reduce the computational load of CFAR detection, and improve the performance of radar detection.

[0005] In a first aspect, embodiments of this disclosure provide a constant false alarm rate (CFAR) detection method, including:

[0006] The raw signals acquired by the millimeter-wave radar are processed to obtain the range-Doppler spectrum RDM matrix of the acquisition environment of the millimeter-wave radar.

[0007] The window geometry corresponding to the unit under test in the RDM is determined, and a reference window area and a protection window area with the window geometry are formed relative to the unit under test. The unit under test is a matrix element in the RDM matrix.

[0008] The constant false alarm detection threshold of the unit under test is determined based on the element values ​​of the matrix elements contained in the reference window area and the protection window area.

[0009] The constant false alarm rate (CFAR) detection result of the tested unit is determined based on the CFAR detection threshold.

[0010] Secondly, embodiments of this disclosure provide a constant false alarm rate (CFAR) detection device, comprising:

[0011] The raw signal processing module is used to process the raw signals acquired by the millimeter-wave radar to obtain the range Doppler spectrum RDM matrix of the acquisition environment of the millimeter-wave radar.

[0012] The window area forming module is used to determine the window geometry corresponding to the unit under test in the RDM, and to form a reference window area and a protective window area with the window geometry relative to the unit under test, wherein the unit under test is a matrix element in the RDM matrix;

[0013] The detection threshold determination module is used to determine the constant false alarm detection threshold of the unit under test based on the element values ​​of the matrix elements contained in the reference window area and the protection window area.

[0014] The detection result determination module is used to determine the constant false alarm rate (CFAR) detection result of the tested unit based on the CFAR detection threshold.

[0015] Thirdly, embodiments of this disclosure provide an electronic device, including:

[0016] At least one processor; and

[0017] A memory that is communicatively connected to at least one processor; wherein,

[0018] The memory stores a computer program that can be executed by at least one processor, such that the at least one processor is able to perform the constant false alarm rate (CFAR) detection method provided in the first aspect embodiment described above.

[0019] Fourthly, embodiments of this disclosure provide a computer-readable storage medium storing computer instructions that, when executed by a processor, implement the constant false alarm rate (CFAR) detection method provided in the first aspect of the embodiments described above.

[0020] The constant false alarm rate (CFAR) detection method, apparatus, device, and storage medium of this invention process the raw signal acquired by millimeter-wave radar to obtain the range-Doppler spectrum (RDM) matrix of the acquisition environment of the millimeter-wave radar; determine the window geometry corresponding to the measured unit in the RDM, and form a reference window area and a protection window area with the window geometry relative to the measured unit, wherein the measured unit is a matrix element in the RDM matrix; determine the CFAR detection threshold of the measured unit based on the element values ​​of the matrix elements contained in the reference window area and the protection window area; and determine the CFAR detection result of the measured unit based on the CFAR detection threshold. The above technical solution can form reference window areas and protection window areas with various window geometries. The window geometry of the reference and protection window areas of the measured unit in this solution differs from the single rectangular shape of traditional constant false alarm rate (CFAR) detection methods, effectively reducing the number of units participating in the CFAR detection calculation process and lowering the computational load. Compared to the rectangular shape, using the window geometry provided in this solution for CFAR detection effectively reduces interference from low-correlation units in the four corner regions of the RDM matrix, ensuring the accuracy of CFAR detection and lowering the false alarm rate. By adopting this technical solution, the computational load of CFAR detection is reduced, the interference of noise and clutter on radar detection is decreased, the accuracy of CFAR detection is guaranteed, and the performance of radar detection is improved.

[0021] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a flowchart of a constant false alarm rate (CFAR) detection method provided in Embodiment 1 of the present invention;

[0024] Figure 2A This is a 2D-CFAR image with a rectangular window geometry involved in a constant false alarm rate (CFAR) detection method provided in Embodiment 1 of the present invention.

[0025] Figure 2B This is a 2D-CFAR image with a rhomboid window geometry involved in a constant false alarm rate (CFAR) detection method provided in Embodiment 1 of the present invention.

[0026] Figure 3This is a flowchart of a constant false alarm rate (CFAR) detection method provided in Embodiment 2 of the present invention;

[0027] Figure 4 This is an example illustration of the sliding window area involved in a constant false alarm rate (CFAR) detection method provided in Embodiment 2 of the present invention;

[0028] Figure 5A This is an example illustration of an incompletely covered sliding window area involved in a constant false alarm rate (CFAR) detection method provided in Embodiment 2 of the present invention;

[0029] Figure 5B This is another example illustration of the sliding window area not being completely covered in the constant false alarm rate detection method provided in Embodiment 2 of the present invention;

[0030] Figure 5C This is another example of the sliding window area not being fully covered in the constant false alarm rate detection method provided in Embodiment 2 of the present invention;

[0031] Figure 5D This is another example of the sliding window area not being fully covered in the constant false alarm detection method provided in Embodiment 2 of the present invention;

[0032] Figure 5E This is an example illustration of a constant false alarm rate (CFAR) detection method provided in Embodiment 2 of the present invention, in which the sliding window area is completely covered.

[0033] Figure 6 This is an example illustration of the extended RDM matrix involved in a constant false alarm rate (CFAR) detection method provided in Embodiment 2 of the present invention;

[0034] Figure 7 This is a 2D-CFAR diagram in the extended RDM matrix involved in a constant false alarm rate (CFAR) detection method provided in Embodiment 2 of the present invention;

[0035] Figure 8 This is a schematic diagram of the structure of a constant false alarm detection device provided in Embodiment 3 of the present invention;

[0036] Figure 9 This is a schematic diagram of the structure of an electronic device provided in Embodiment 4 of the present invention. Detailed Implementation

[0037] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0038] It should be noted that the terms "first," "second," and "target," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0039] Example 1

[0040] Figure 1 This is a flowchart of a constant false alarm rate (CFAR) detection method provided in Embodiment 1 of the present invention. This embodiment is applicable to the situation of determining target signals in signals acquired by millimeter-wave radar. The method can be executed by a CFAR detection device, which can be implemented in hardware and / or software.

[0041] In this embodiment, the millimeter-wave radar emits radar signals. While the echo signal is received by the receiver, some interference signals are also received along with the echo signal. To determine whether the target signal exists in the received echo, the radar signal processor needs to make a judgment on the presence or absence of target information in the echo signal. This is achieved by using the Constant False Alarm Rate (CFAR) method for radar detection to determine the target signal of the target being measured.

[0042] Among them, constant false alarm rate (CFAR) detection is a target detection method based on millimeter-wave radar. Specifically, it can be understood as a technical method that maximizes the target detection probability while keeping the false alarm rate constant by setting a window area to estimate the parameters and probabilistically model the signals collected by the radar, dynamically adjusting the detection threshold according to radar clutter data.

[0043] In this embodiment, two-dimensional constant false alarm rate (CFAR) detection technology is used to determine the target signal.

[0044] like Figure 1 As shown, the method includes:

[0045] S101. Process the raw signals acquired by the millimeter-wave radar to obtain the range-Doppler spectrum RDM matrix of the acquisition environment of the millimeter-wave radar.

[0046] In this embodiment, the original signal can be the echo signal of the electromagnetic wave signal transmitted by the millimeter-wave radar in the acquisition environment; specifically, it can be understood as the unprocessed signal acquired by the millimeter-wave radar. The Range-Doppler map (RDM) matrix can be understood as an M*N matrix, such as 512*256, of the Range-Doppler spectrum RDM. The Range-Doppler spectrum RDM can be understood as the range-Doppler spectrum obtained by processing the multiple-cycle pulse sequence transmitted by the radar and the echo information in both fast and slow time dimensions.

[0047] In RDM (Radar Dynamics Detection and Ranging), a variety of acoustic signals can be included, such as background noise, environmental clutter, and target information. Background noise can be understood as ground clutter, other electromagnetic signals, and background noise from circuit components; environmental clutter can be understood as scattered echo signals generated by natural environments such as clouds, rain, snow, fog, and hail. Target information can be understood as the echo signal of the target being measured, acquired by the millimeter-wave radar.

[0048] Specifically, the raw signals acquired by the millimeter-wave radar are mixed to obtain mixed signals; the mixed signals are then processed by a two-dimensional fast fourier transform (2D-FFT) to obtain range and velocity data values, and the range-Doppler spectrum RDM matrix of the acquisition environment of the millimeter-wave radar is determined.

[0049] For example, a millimeter-wave radar is installed on a vehicle traveling on a road. The target being measured can be, for example, a vehicle in front. The millimeter-wave radar collects the raw signal, performs frequency mixing and two-dimensional fast Fourier transform on the raw signal, and obtains an RDM matrix of the vehicle in the road environment, including the speed and distance data of the vehicle in front. The RDM matrix also includes background noise and environmental clutter interference signals.

[0050] S102. Determine the window geometry corresponding to the unit under test in the RDM, and form a reference window area and a protection window area with the window geometry relative to the unit under test.

[0051] In this embodiment, the Cell Under Test (CUT) is a matrix element in the Range Doppler Spectrum (RDM) matrix. The RDM matrix can include M*N matrix elements, each corresponding to a cell. Correspondingly, the RDM includes multiple cells. The CUT is also a cell in the RDM, and the echo signal of the target exists in the RDM matrix in the form of the CUT. Each CUT may be identified as the target signal of the target.

[0052] Window geometry can be understood as the shape of a window area formed by multiple elements. It can be a non-rectangular polygon, such as a rhombus, triangle, quadrilateral, or pentagon. The reference window area can be understood as a reference window region formed by multiple elements in the RDM based on the window geometry. The protection window area can be understood as a protection window region formed by multiple elements in the RDM based on the window geometry. Both the reference window area and the protection window area are formed by defining the matrix elements according to the window geometry, using a set number of elements as the window width. It is understood that the reference window area and the protection window area have the same window geometry.

[0053] Specifically, the window geometry corresponding to the unit under test is predetermined. Based on the predetermined window geometry, corresponding matrix elements are delineated around the unit under test to form a reference window area and a protection window area relative to the unit under test.

[0054] Currently, constant false alarm rate (CFAR) detection methods are generally based on delineating multiple units in a rectangular shape to form a reference window area and a protection window area. Figure 2A This is a 2D-CFAR image with a rectangular window geometry involved in the constant false alarm rate (CFAR) detection method provided in Embodiment 1 of the present invention, as shown in the example. Figure 2A As shown, in the RDM matrix, a 2D-CFAR is formed in a rectangular shape relative to the unit under test 11: according to the set window width, the corresponding matrix elements are delineated to form a rectangular protective window area 12 and a reference window area 13.

[0055] In this embodiment, a reference window area and a protection window area can be formed based on various window geometries. Figure 2B This is a 2D-CFAR image with a rhomboid window geometry involved in the constant false alarm rate (CFAR) detection method provided in Embodiment 1 of the present invention, as shown in the example. Figure 2B As shown, in the RDM matrix, a 2D-CFAR with a diamond shape relative to the unit under test 14 is formed: according to the set window width, the corresponding matrix elements are delineated to form a diamond-shaped protection window area 15 and a reference window area 16.

[0056] In the RDM matrix, the rectangular 2D-CFAR has a lot of information that is not highly correlated with the measured unit. Using the rectangular 2D-CFAR for constant false alarm rate (CFAR) detection results in a certain false alarm rate, leading to low radar detection performance. Furthermore, using a rectangular window for CFAR detection also results in a high computational load due to multiple computational units, which has a certain impact on the radar's real-time performance.

[0057] For example, such as Figure 2A and Figure 2B As shown, the number of units required to form the reference window area and the protection window area based on the same window width varies under different window geometries. For the same window width, the number of units (matrix elements) required for a rectangular 2D-CFAR is twice that of a rhomboid 2D-CFAR.

[0058] By employing various window geometries in this embodiment to determine the reference window area and protection window area of ​​the unit under test, the number of units that need to be calculated during constant false alarm rate (CFAR) detection is effectively reduced, thus lowering the computational load of CFAR detection and improving radar detection speed and efficiency.

[0059] S103. Determine the constant false alarm detection threshold of the unit under test based on the element values ​​of the matrix elements contained in the reference window area and the protection window area.

[0060] In this embodiment, the element value of the matrix element can be understood as the power amplitude corresponding to each matrix element in the RDM matrix. The constant false alarm rate (CFAR) detection threshold can be understood as a critical value used to determine whether the echo signal of the unit under test is the target signal.

[0061] Specifically, based on the power amplitude of each matrix element forming the reference window area, the element values ​​of the matrix elements contained in the reference window area are determined; based on the power amplitude of each matrix element forming the protection window area, the element values ​​of the matrix elements contained in the protection window area are determined. Combining the element values ​​of the matrix elements contained in the reference window area and the protection window area, corresponding calculations are performed to determine the constant false alarm rate (CFAR) detection threshold of the unit under test.

[0062] S104. Determine the constant false alarm rate (CFAR) detection result of the tested unit based on the CFAR detection threshold.

[0063] In this embodiment, the constant false alarm rate (CFAR) detection result can be understood as whether the echo signal of the unit under test is the target signal, that is, whether the unit under test is the target unit.

[0064] Specifically, the constant false alarm rate (CFAR) detection threshold is compared with the element values ​​of the unit under test, and the CFAR detection result of the unit under test is determined based on the comparison result.

[0065] In this embodiment, the range-Doppler spectrum (RDM) matrix of the acquisition environment of the millimeter-wave radar is obtained by processing the raw signal acquired by the millimeter-wave radar. The window geometry corresponding to the measured unit in the RDM is determined, and a reference window area and a protection window area with window geometry are formed relative to the measured unit. The measured unit is the matrix element in the RDM matrix. The constant false alarm rate (CFAR) detection threshold of the measured unit is determined according to the element values ​​of the matrix elements contained in the reference window area and the protection window area. The CFAR detection result of the measured unit is determined according to the CFAR detection threshold. The above technical solution can form reference window areas and protection window areas with various window geometry. The window geometry of the reference window area and protection window area of ​​the measured unit in this solution is different from the single rectangular shape of the traditional CFAR detection method, which effectively reduces the number of units participating in the CFAR detection calculation process and reduces the computational load of CFAR detection. Compared with the rectangular shape, the window geometry provided by this solution for CFAR detection effectively reduces the interference of low-correlation units in the four corner areas of the RDM matrix, ensures the accuracy of CFAR detection, and reduces the false alarm rate. By adopting the above technical solution, the computational load of constant false alarm rate (CFAR) detection is reduced, the interference of noise and clutter on radar detection is reduced, the accuracy of CFAR detection is guaranteed, and the performance of radar detection is improved.

[0066] As a first optional embodiment of the embodiments, based on the above embodiments, before determining the set geometric shape corresponding to the unit under test in the RDM, this first optional embodiment further includes: traversing each matrix element in the RDM matrix according to the element subscript order, and taking each traversed matrix element as the unit under test.

[0067] In this optional embodiment, each matrix element in the RDM matrix has a corresponding element subscript. The matrix elements in the RDM matrix are traversed sequentially according to the element subscript order. Each traversed matrix element can be used as a unit under test, thereby forming a reference window area and a protection window area relative to the window geometry of the unit under test.

[0068] For example, in the RDM matrix, the matrix elements are traversed according to their element indices (i, j), i.e., (1,1), (1,2)...(M,N) are traversed sequentially. Each matrix element can serve as the unit under test (UDT) H(i,j) in the RDM, forming a reference window area and a protection window area with corresponding window geometry. For example, if H1 is determined as the UDT, a reference window area and a protection window area are formed relative to H1. Based on the element values ​​of the matrix elements contained in the reference window area and the protection window area, the constant false alarm rate (CFAR) detection threshold of the UDT H1 is determined, and it is determined whether the echo signal of H1 is the target signal.

[0069] The above technical solution traverses the RDM matrix, and each element can be used as a unit under test. Correspondingly, each unit under test can have a reference window area and a protection window area with a window geometry relative to the unit under test, which ensures the comprehensiveness of constant false alarm detection of matrix elements in the RDM matrix and enhances the performance of millimeter-wave radar detection.

[0070] Example 2

[0071] Figure 3 This is a flowchart of a constant false alarm rate (CFAR) detection method provided in Embodiment 2 of the present invention. This embodiment is a further optimization of any of the above embodiments and can be applied to the situation of determining the target signal in the signal acquired by millimeter-wave radar. The method can be executed by a CFAR detection device, which can be implemented in hardware and / or software.

[0072] like Figure 3 As shown, the method includes:

[0073] S201. Process the raw signals acquired by the millimeter-wave radar to obtain the range-Doppler spectrum RDM matrix of the acquisition environment of the millimeter-wave radar.

[0074] S202. Use the set rhombus shape as the window geometry of the unit under test.

[0075] In this embodiment, the defined rhombus shape is a complete rhombus "◆". Regardless of the position of the measured unit in the RDM matrix, its corresponding window geometry is always a rhombus.

[0076] S203. Based on the given protection window width and reference window width, construct a sliding window area with a diamond shape.

[0077] The sliding window region includes a rhombus-shaped center point element, a protective sliding region, and a reference sliding region surrounding the protective sliding region. The sliding window region can be understood as the area capable of sliding within the RDM matrix in a complete rhombus shape. The rhombus-shaped center point element can be understood as the element located at the center of the rhombus-shaped sliding window region. The protective sliding region can be understood as the protective sliding region established around the rhombus-shaped center point element based on the width of the protective window. The reference sliding region can be understood as the reference sliding region established outside the protective sliding region based on the width of the reference window.

[0078] For example, Figure 4 This is an example illustration of the sliding window area involved in a constant false alarm rate (CFAR) detection method provided in Embodiment 2 of the present invention. Figure 4As shown, given a protection window width G=2 and a reference window width T=2, a rhombus-shaped sliding window area is constructed. Centered on the rhombus center point unit 21, a protection sliding area 22 is constructed around the rhombus center point unit 21 based on a protection window width of G=2. A reference sliding area 23 is constructed around the protection sliding area 22 based on a reference window width of T=2.

[0079] S204. Slide the sliding window area to make the center point of the rhombus coincide with the measured unit.

[0080] In this embodiment, the sliding window area is slid within the RDM matrix so that the center point of the rhombus in the sliding window area coincides with the unit under test.

[0081] S205. Determine the matrix elements in the RDM that fall within the protection sliding zone to form the protection window area of ​​the unit under test.

[0082] In this embodiment, while the rhomboid center point element of the sliding window area coincides with the unit under test, the protective sliding area of ​​the sliding window area also coincides with the RDM matrix. Based on the overlapping part, the matrix elements in the RDM matrix that fall into the protective sliding area are determined, and the protective window area of ​​the unit under test is constructed.

[0083] S206. Determine the matrix elements in the RDM that fall within the reference sliding area to form the reference window area of ​​the unit under test.

[0084] In this embodiment, while the rhomboid center point unit of the sliding window area coincides with the unit under test, the reference sliding area of ​​the sliding window area also coincides with the RDM matrix. Based on the overlapping part, the matrix elements in the RDM matrix that fall into the reference sliding area are determined, and the reference window area of ​​the unit under test is constructed.

[0085] It is understandable that when the center point of the rhombus in the sliding window area coincides with the measured element, the rhombus sliding window area may not have completely slid into the RDM matrix. By combining different protection window widths and reference window widths, protection window areas and reference window areas of different shapes can be constructed. These can be complete rhombus shapes "◆" or partial rhombus shapes, such as triangles, quadrilaterals, and pentagons. Among these, triangles can include isosceles triangles "◆". ▲、 "and right triangle"

[0086] For example, Figure 5A This is an example illustration of an incompletely covered sliding window area involved in a constant false alarm rate (CFAR) detection method provided in Embodiment 2 of the present invention. Figure 5AAs shown, the protective sliding area G=2 and the reference sliding area T=2 of the sliding window region. When the coordinates of the measured element are (1, 1), the overlapping part of the sliding window region and the RDM matrix is ​​a right triangle. Correspondingly, the reference window area and the protection window area are shaped like right-angled triangles.

[0087] Figure 5B This is another example illustration of the incomplete coverage of the sliding window area involved in a constant false alarm rate (CFAR) detection method provided in Embodiment 2 of the present invention. Figure 5B As shown, the protective sliding area G=2 and the reference sliding area T=2 in the sliding window region. When the coordinates of the measured element are (2, 1), the overlapping part of the sliding window region and the RDM matrix is ​​a quadrilateral. Correspondingly, the reference window region and the protective window region are both quadrilaterals.

[0088] Figure 5C This is another example of incomplete coverage of the sliding window area involved in the constant false alarm rate (CFAR) detection method provided in Embodiment 2 of the present invention. Figure 5C As shown, the protective sliding area G=2 and the reference sliding area T=2 in the sliding window region. When the coordinates of the measured unit are (5, 1), the overlapping part of the sliding window region and the RDM matrix is ​​an isosceles triangle "▲". Correspondingly, the reference window region and the protective window region are also isosceles triangles "▲".

[0089] Figure 5D This is another example illustration of incomplete coverage of the sliding window area involved in the constant false alarm rate (CFAR) detection method provided in Embodiment 2 of the present invention. For example... Figure 5D As shown, the protective sliding area G=2 and the reference sliding area T=2 in the sliding window region. When the coordinates of the measured element are (2, 2), the overlapping part of the sliding window region and the RDM matrix is ​​pentagonal. Correspondingly, the reference window region and the protective window region are both pentagonal in shape.

[0090] Figure 5E This is an example illustration showing that the sliding window area is completely covered in the constant false alarm rate (CFAR) detection method provided in Embodiment 2 of the present invention. Figure 5E As shown, the protective sliding area G=2 and the reference sliding area T=2 in the sliding window region. When the coordinates of the measured unit are (5, 5), the overlapping part of the sliding window region and the RDM matrix is ​​a rhombus "◆". Correspondingly, the reference window region and the protective window region are both rhombus "◆".

[0091] S207. Based on the element indices of the matrix elements contained in the reference window area and the protection window area, determine the reference matrix elements that are only in the reference window area.

[0092] In this embodiment, the reference matrix element can be understood as the matrix element that constructs the reference window area.

[0093] Specifically, the reference window area has a reference window width, and the protection window area also has a protection window width. Based on the matrix element indices of the unit under test, combined with the reference window width of the reference window area and the protection window width of the protection window area, the element indices of the matrix elements contained in the reference window area and the protection window area are determined. Based on the element indices of the matrix elements in the reference window area, the reference matrix elements that are only located in the reference window area are determined.

[0094] For example, G=2, T=2, the unit under test (DUT) is H(5,5), and the window geometry is rhomboid. Combining the matrix element indices of the DUT, the widths of the reference and protection windows, and the indices of the matrix elements constructing the reference and protection window areas, it can be determined that matrix element J1(5,6) is only located within the protection window area; matrix element J2(4,7) is only located within the reference window area. Therefore, matrix element J2(4,7) can be determined as a reference matrix element that is only located within the reference window area.

[0095] S208. Obtain the number of elements in the included reference matrix and the reference element value of each reference matrix element.

[0096] In this embodiment, the reference element value can be understood as the power amplitude of the reference matrix element.

[0097] Specifically, in the RDM matrix, the number of matrix elements that construct the unit under test, the guard window, and the reference window is as follows:

[0098] X = 2(T+G)(T+G+1)+1

[0099] Where X represents the total number of matrix elements used to construct the unit under test, the protection window region, and the reference window region; T represents the reference window width of the reference window region; and G represents the protection window width of the protection window region.

[0100] In the RDM matrix, the total number of matrix elements that construct the protection window area is as follows:

[0101] X G =2G 2 +2G

[0102] Among them, X G This represents the total number of matrix elements in the protected window area.

[0103] Therefore, in the RDM matrix, the total number of all reference matrix elements for the construction reference window area is as follows:

[0104] X T =XX G -1 = 2T 2 +4TG+2T

[0105] Among them, X T This indicates the total number of matrix elements in the reference window area, i.e., the total number of reference matrix elements.

[0106] Specifically, within the reference window area, each reference matrix element has its corresponding power amplitude, and the power amplitude of each reference matrix element is determined as the reference element value.

[0107] S209. Based on the number of elements and the values ​​of each reference element, determine the average noise power of the reference window area.

[0108] In this embodiment, the average noise power can be understood as the average power amplitude of all reference matrix elements in the reference window area. Combining the number of reference matrix elements and the reference element value of each reference matrix element, the average noise power of the 2D-CFAR reference window area is calculated as follows:

[0109]

[0110] Where P represents the average noise power of the 2D-CFAR reference window region, and RDM(i,j) represents the reference element value of each reference matrix element.

[0111] S210. Based on the average noise power and the given threshold relationship, obtain the constant false alarm detection threshold of the unit under test.

[0112] In this embodiment, the given threshold relationship can be understood as a relationship used to calculate the constant false alarm detection threshold based on the average noise power.

[0113] Specifically, based on the average noise power P and the given threshold relationship, the constant false alarm rate (CFAR) detection threshold Z of the unit under test is calculated, as shown in the following formula:

[0114] Z = P * a or Z = P + b

[0115] Where Z is the constant false alarm rate (CFAR) detection threshold, P is the average noise power of the reference window region, a is the threshold factor, and b is the bias. The threshold factor a and bias b are empirical values ​​and can be determined according to different needs; this embodiment does not impose any limitations on them.

[0116] S211. Obtain the matrix element values ​​of the unit under test from the RDM matrix.

[0117] In this embodiment, each matrix element in the RDM matrix has its corresponding element value, and the matrix element value corresponding to the unit under test is obtained.

[0118] S212. If the matrix element value is greater than or equal to the constant false alarm rate (CFAR) detection threshold, then the CFAR detection result is determined to be the target unit; otherwise, the CFAR detection result is determined to be the non-target unit.

[0119] In this embodiment, the matrix element values ​​of the unit under test are compared with the constant false alarm detection threshold. If the matrix element values ​​of the unit under test are greater than or equal to the constant false alarm detection threshold, the echo signal of the unit under test can be determined to be the target signal of the target under test, that is, the unit under test is the target unit. If the matrix element values ​​of the unit under test are less than the constant false alarm detection threshold, the echo signal of the unit under test can be determined to be not the target signal of the target under test, that is, the unit under test is not the target unit.

[0120] For example, as described in the following formula:

[0121]

[0122] Where CUT(i,j) can be understood as the unit under test in the (i,j) coordinate; i and j are the values ​​of the horizontal and vertical coordinates of the unit under test in RDM, where i∈M; j∈N; RDM(i,j) is the power amplitude of the echo signal of the unit under test in the (i,j) coordinate; Z is the constant false alarm detection threshold.

[0123] In this embodiment, the range-Doppler spectrum (RDM) matrix of the acquisition environment of the millimeter-wave radar is obtained by processing the raw signal acquired by the millimeter-wave radar; a set rhombus shape is used as the window geometry of the unit under test; a sliding window region with a rhombus shape is constructed based on a given guard window width and a reference window width; the sliding window region is slid so that the center point of the rhombus coincides with the unit under test; matrix elements in the RDM that fall within the guard sliding region are determined to form the guard window region of the unit under test; matrix elements in the RDM that fall within the reference sliding region are determined to form the reference window region of the unit under test; and the reference window region and the guard window region are used to form the reference window region of the unit under test. The index of the matrix elements contained in the matrix is ​​used to determine the reference matrix elements that are only in the reference window area; the number of elements in the contained reference matrix elements and the reference element value of each reference matrix element are obtained; based on the number of elements and the reference element value, the average noise power of the reference window area is determined; according to the average noise power and the given threshold relationship, the constant false alarm detection threshold of the unit under test is obtained; the matrix element value of the unit under test is obtained from the RDM matrix; if the matrix element value is greater than or equal to the constant false alarm detection threshold, the constant false alarm detection result is determined that the unit under test is the target unit; otherwise, the constant false alarm detection result is determined that the unit under test is a non-target unit. The above technical solution determines the shape of the protection window area and the reference window area by the overlapping part of the sliding window area and the RDM matrix. Compared with the traditional rectangular window area, it reduces the number of units involved in the constant false alarm rate (CFAR) detection calculation. This effectively reduces the computational load of CFAR detection without increasing the false alarm rate, improves the efficiency of CFAR detection, increases the speed of radar detection, and ensures the real-time performance of radar detection. By reducing the input of low-correlation units, the weight of each matrix element in the reference window area along the coordinate axis is enhanced, thereby improving the robustness and accuracy of detection.

[0124] As a first optional embodiment of the embodiments, based on the above embodiments, this first optional embodiment further optimizes and adds the step of determining the window geometry corresponding to the unit under test in the RDM matrix, and forming a reference window area and a protective window area with the window geometry relative to the unit under test, including:

[0125] a1) Use the set rhombus shape as the window geometry of the unit under test, and obtain the element subscript of the unit under test.

[0126] In this embodiment, the set rhombus shape is used as the window geometry of the unit under test H, and the element subscripts of the unit under test H are obtained as (i,j), where i∈M; j∈N. In the element subscripts of H(i,j), i and j can be determined according to actual needs, and this embodiment does not impose any restrictions on them.

[0127] b1) The RDM matrix is ​​expanded based on the reference window width to obtain the expanded RDM matrix.

[0128] In this case, the difference between the horizontal and vertical subscript values ​​of the corresponding extended element subscript of the unit under test in the extended RDM matrix and the given reference window width are all positive numbers.

[0129] In this embodiment, the extended RDM matrix can be understood as the matrix obtained after the RDM matrix has been extended.

[0130] Specifically, the original RDM matrix is ​​expanded around its perimeter to obtain an expanded RDM matrix with increased horizontal and vertical coordinates. In the expanded RDM matrix, the index of each matrix element relative to the element in the expanded RDM matrix is ​​redefined.

[0131] For example, the index of the extended element corresponding to the unit under test in the extended RDM matrix is ​​(5,5). Given a reference window width T=4, the horizontal and vertical index values ​​of the extended element are both 5, and the difference between them and the given reference window width is a positive number.

[0132] c1) Using the unit under test as the center point, and combining the given protection window width, select matrix elements with the rhombus shape from the extended RDM matrix to form a protection window area.

[0133] In this embodiment, with the unit under test as the center point and in combination with the given protection window width, a diamond-shaped matrix element is delineated around the unit under test in the extended RDM matrix with the given protection window width. The diamond-shaped protection window area in the extended RDM matrix is ​​composed of multiple delineated matrix elements.

[0134] d1) Using the unit under test as the center point, and combining the given reference window width, delineate the matrix elements with the rhombus shape from the extended RDM matrix to form the reference window area.

[0135] In this embodiment, with the unit under test as the center point and in combination with the given reference window width, a diamond-shaped matrix element is delineated around the unit under test in the extended RDM matrix with the given reference window width. The multiple delineated matrix elements constitute the diamond reference window area in the extended RDM matrix.

[0136] Furthermore, the RDM matrix is ​​expanded based on the reference window width, including:

[0137] b11) Obtain the original row values ​​and original column values ​​of the RDM matrix, and determine the sum of the widths of the reference window and the protection window.

[0138] In this embodiment, the original row values ​​can be understood as the number of x-coordinates in the RDM matrix. The original column values ​​can be understood as the number of y-coordinates in the RDM matrix.

[0139] Specifically, the RDM matrix is ​​an M*N matrix with original row values ​​M and original column values ​​N. The original row values ​​M and original column values ​​N of the RDM matrix are obtained. The sum of the reference window width and the protection window width is also determined.

[0140] For example, the reference window width T = 2, the protection window width G = 2, and the sum of the widths of the reference window and the protection window is T + G = 4.

[0141] b12) The sum of twice the width and the original row values ​​is used as the expanded row values, and the sum of twice the width and the original column values ​​is used as the expanded column values ​​to form the initial expanded RDM matrix.

[0142] In this embodiment, the initial extended RDM matrix can be understood as a matrix that only extends the Doppler spectrum RDM and has no actual element content.

[0143] Specifically, the sum of twice the width and the original row value M is used as the extended row value (2T+2G+M), and the sum of twice the width and the original column value N is used as the extended column value (2T+2G+N). The initial extended RDM matrix is ​​formed based on the extended row value and the extended column value.

[0144] For example, Figure 6 This is an example illustration of the extended RDM matrix involved in a constant false alarm rate (CFAR) detection method provided in Embodiment 2 of the present invention, as shown in the figure. Figure 6 As shown, the original row values ​​M = 18, N = 12, the reference window width T = 2, the protection window width G = 2, and an initial expanded RDM matrix with expanded row values ​​of 26 and expanded column values ​​of 20 is constructed.

[0145] b13) Fill the element values ​​of each matrix element into the initial extended RDM matrix according to the corresponding extended element subscripts.

[0146] The expanded element subscripts of the matrix elements are determined based on the original element subscripts and the width of the reference window.

[0147] In this embodiment, the extended element indices of the matrix elements in the extended RDM matrix are determined based on the original element indices and the sum of the widths of the reference window and the protection window. Based on the original element indices, the extended elements are extended in two directions: upward / downward and left / right, so that the horizontal and vertical coordinates of the extended element indices are the sum or difference of the original element indices and their widths in that direction, respectively. After determining the extended element indices, the element values ​​of the original element indices are filled into the corresponding matrix elements of the extended RDM matrix.

[0148] b14) Set the element values ​​corresponding to the subscripts of the remaining extended elements in the initial extended RDM matrix to the set values ​​to obtain the filled extended RDM matrix.

[0149] In this embodiment, the initial expanded RDM matrix is ​​partially filled with corresponding element values. There are still unfilled expanded matrix elements in the initial expanded RDM matrix. The element value corresponding to the element index of each unfilled expanded matrix element is set to a set value to obtain the filled expanded RDM matrix. The set value can be 0 or other values; the specific set value is determined according to actual needs, and this embodiment does not impose any limitations on this.

[0150] It is understandable that the edge matrix elements of the original RDM matrix can also be filled using a complementary filling method, where some matrix element values ​​in the RDM matrix are filled into another part.

[0151] In this embodiment, after filling the RDM matrix, even if the center point cell of the rhombus in the sliding window area coincides with the measured cell located at the edge coordinates, a complete rhombus-shaped protection window area and reference window area can still be achieved. Figure 7 This is a 2D-CFAR diagram in the extended RDM matrix involved in the constant false alarm rate (CFAR) detection method provided in Embodiment 2 of the present invention, such as... Figure 7 As shown, the coordinates of the measured unit are (1,1). If the RDM matrix is ​​not expanded, the overlapping part of the sliding window area and the RDM matrix is ​​only as shown. Figure 5A The right-angled triangle 2D-CFAR shown; after expanding the RDM matrix, the sliding window area in the expanded RDM matrix becomes a complete rhombus shape in the 2D-CFAR.

[0152] The above technical solution enables the edge matrix elements of the original RDM matrix to construct corresponding rhomboid reference window areas, achieving rhomboid CFAR detection and ensuring the comprehensiveness of RDM matrix detection.

[0153] Example 3

[0154] Figure 8 This is a schematic diagram of a constant false alarm rate (CFAR) detection device provided in Embodiment 3 of the present invention. Figure 8 As shown, the device includes:

[0155] The raw signal processing module 31 is used to process the raw signals acquired by the millimeter-wave radar to obtain the range Doppler spectrum RDM matrix of the acquisition environment of the millimeter-wave radar.

[0156] The window area forming module 32 is used to determine the window geometry corresponding to the unit under test in the RDM, and to form a reference window area and a protective window area with the window geometry relative to the unit under test, wherein the unit under test is a matrix element in the RDM matrix;

[0157] The detection threshold determination module 33 is used to determine the constant false alarm detection threshold of the unit under test based on the element values ​​of the matrix elements contained in the reference window area and the protection window area.

[0158] The detection result determination module 34 is used to determine the constant false alarm rate (CFAR) detection result of the tested unit based on the CFAR detection threshold.

[0159] The constant false alarm rate (CFAR) detection device used in this technical solution reduces the computational load of CFAR detection, reduces the interference of noise and clutter on radar detection, ensures the accuracy of CFAR detection, and improves the performance of radar detection.

[0160] Optionally, the device further includes:

[0161] The matrix traversal module is used to traverse each matrix element in the RDM matrix according to the element index order, and to treat each traversed matrix element as a test unit.

[0162] Optionally, the window area forming module 32 is specifically applied to:

[0163] The defined rhombus shape is used as the window geometry of the unit under test.

[0164] Based on the given protection window width and reference window width, a sliding window area with the diamond shape is constructed, wherein the sliding window area includes a diamond center point unit, a protection sliding area, and a reference sliding area contained outside the protection sliding area;

[0165] Slide the sliding window area to align the rhombus center point unit with the unit under test;

[0166] The matrix elements in the RDM that fall within the protection sliding area constitute the protection window area of ​​the unit under test;

[0167] The matrix elements in the RDM that fall within the reference sliding area are determined to form the reference window area of ​​the unit under test.

[0168] Optionally, the window area forming module 32 includes:

[0169] The element subscript acquisition unit is used to take the set rhombus shape as the window geometry of the unit under test and acquire the element subscript of the unit under test.

[0170] A matrix expansion processing unit is used to expand the RDM matrix based on the reference window width to obtain an expanded RDM matrix, wherein the difference between the horizontal and vertical index values ​​of the corresponding expanded element subscripts of the unit under test in the expanded RDM matrix and the given reference window width are both positive numbers.

[0171] A protection window construction unit is used to delineate matrix elements with the rhomboid shape from the extended RDM matrix with the unit under test as the center point and in combination with the given protection window width to form a protection window area.

[0172] The reference window construction unit is used to delineate matrix elements with the rhombus shape from the extended RDM matrix with the unit under test as the center point and in combination with the given reference window width to form a reference window area.

[0173] Optionally, the matrix augmentation processing unit is specifically applied to:

[0174] Obtain the original row and column values ​​of the RDM matrix, and determine the sum of the widths of the reference window and the protection window;

[0175] The sum of twice the width and the original row values ​​is used as the expanded row value, and the sum of twice the width and the original column values ​​is used as the expanded column value, thus forming the initial expanded RDM matrix;

[0176] The element values ​​of each matrix element are filled into the initial expanded RDM matrix according to the corresponding expanded element subscripts, wherein the expanded element subscripts of the matrix elements are determined based on the original element subscripts and the width of the reference window.

[0177] Set the element values ​​corresponding to the subscripts of the remaining expanded elements in the initial expanded RDM matrix to the set values ​​to obtain the filled expanded RDM matrix.

[0178] Optionally, the detection threshold determination module 33 is specifically applied to:

[0179] Based on the element indices of the matrix elements contained in the reference window area and the protection window area, determine the reference matrix elements that are only in the reference window area;

[0180] Obtain the number of elements in the included reference matrix, and the reference element value of each of the reference matrix elements;

[0181] Based on the number of elements and the values ​​of each reference element, the average noise power of the reference window area is determined;

[0182] Based on the average noise power and the given threshold relationship, the constant false alarm detection threshold of the unit under test is obtained.

[0183] Optionally, the detection result determination module 34 is specifically applied to:

[0184] Obtain the matrix element values ​​of the unit under test from the RDM matrix;

[0185] If the matrix element value is greater than or equal to the constant false alarm rate (CFAR) detection threshold, then the CFAR detection result determines that the tested unit is the target unit; otherwise,

[0186] The constant false alarm rate (CFAR) detection result indicates that the tested unit is a non-target unit.

[0187] The constant false alarm rate (CFAR) detection device provided in this embodiment of the invention can execute the CFAR detection method provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects of the method.

[0188] Example 4

[0189] Figure 9 A schematic diagram of an electronic device 40 that can be used to implement embodiments of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices (e.g., helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein. The electronic device 40 may also include a vehicle with processing capabilities.

[0190] like Figure 9 As shown, the electronic device 40 includes at least one processor 41 and a memory, such as a read-only memory (ROM) 42 or a random access memory (RAM) 43, communicatively connected to the at least one processor 41. The memory stores computer programs executable by the at least one processor. The processor 41 can perform various appropriate actions and processes based on the computer program stored in the ROM 42 or loaded into the RAM 43 from storage unit 48. The RAM 43 may also store various programs and data required for the operation of the electronic device 40. The processor 41, ROM 42, and RAM 43 are interconnected via a bus 44. An input / output (I / O) interface 45 is also connected to the bus 44.

[0191] Multiple components in electronic device 40 are connected to I / O interface 45, including: input unit 46, such as keyboard, mouse, etc.; output unit 47, such as various types of monitors, speakers, etc.; storage unit 48, such as disk, optical disk, etc.; and communication unit 49, such as network card, modem, wireless transceiver, etc. Communication unit 49 allows electronic device 40 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0192] Processor 41 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 41 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. Processor 41 performs the various methods and processes described above, such as the constant false alarm rate (CFAR) detection method.

[0193] In some embodiments, the constant false alarm rate (CFAR) detection method may be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 48. In some embodiments, part or all of the computer program may be loaded and / or installed on electronic device 40 via ROM 42 and / or communication unit 49. When the computer program is loaded into RAM 43 and executed by processor 41, one or more steps of the CFAR detection method described above may be performed. Alternatively, in other embodiments, processor 41 may be configured to perform the CFAR detection method by any other suitable means (e.g., by means of firmware).

[0194] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0195] Computer programs used to implement the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0196] In the context of this invention, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination thereof. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0197] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the electronic device. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0198] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or computing systems that include middleware components (e.g., application servers), or computing systems that include frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include local area networks (LANs), wide area networks (WANs), blockchain networks, and the Internet.

[0199] A computing system can include clients and servers. Clients and servers are generally located far apart and typically interact through communication networks. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a hosting product within the cloud computing service system to address the shortcomings of traditional physical hosts and VPS services, such as high management difficulty and weak business scalability.

[0200] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0201] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A constant false alarm rate detection method, characterized by, The method comprises: processing raw signals collected by a millimeter wave radar to obtain a range-doppler spectrum (RDM) matrix of a collection environment in which the millimeter wave radar is located; determining a window geometry corresponding to a measured unit in the RDM, and forming a reference window region and a protection window region with the window geometry relative to the measured unit, the measured unit being a matrix element in the RDM matrix; determining a constant false alarm detection threshold of the measured unit according to element values of matrix elements contained in the reference window region and the protection window region; determining a constant false alarm detection result of the measured unit according to the constant false alarm detection threshold; wherein the determination of the window geometry corresponding to the measured unit in the RDM matrix, and the formation of the reference window region and the protection window region with the window geometry relative to the measured unit, comprises: taking a set diamond shape as the window geometry of the measured unit, and obtaining element subscripts of the measured unit; performing expansion processing on the RDM matrix based on the reference window width to obtain an expanded RDM matrix, wherein the difference between the horizontal and vertical subscript values of the expanded element subscript corresponding to the measured unit in the expanded RDM matrix and the given reference window width is positive; taking the measured unit as a center point, and combining a given protection window width to enclose matrix elements with the diamond shape from the expanded RDM matrix to form a protection window region; taking the measured unit as a center point, and combining a given reference window width to enclose matrix elements with the diamond shape from the expanded RDM matrix to form a reference window region.

2. The method of claim 1, wherein, Before determining the set geometry corresponding to the measured unit in the RDM, the method further comprises: traversing each matrix element in the RDM matrix in order of element subscripts, and taking each traversed matrix element as a measured unit.

3. The method of claim 1, wherein, The determination of the window geometry corresponding to the measured unit in the RDM, and the formation of the reference window region and the protection window region with the window geometry relative to the measured unit, further comprises: taking a set diamond shape as the window geometry of the measured unit; based on the given protection window width and the reference window width, forming a sliding window region with the diamond shape, wherein the sliding window region contains a diamond center point unit, a protection sliding region, and a reference sliding region outside the protection sliding region; sliding the sliding window region to overlap the diamond center point unit with the measured unit; determining matrix elements in the RDM falling within the protection sliding region to form the protection window region of the measured unit; determining matrix elements in the RDM falling within the reference sliding region to form the reference window region of the measured unit.

4. The method of claim 1, wherein, The expansion processing on the RDM matrix based on the reference window width comprises: obtaining original row values and original column values of the RDM matrix, and determining a width sum of the reference window width and the protection window width; taking twice the width sum and the sum of the original row values as an expanded row value, and taking twice the width sum and the sum of the original column values as an expanded column value to form an initial expanded RDM matrix; filling the element values of the matrix elements into the initial extended RDM matrix according to corresponding extended element subscripts, wherein the extended element subscripts of the matrix elements are determined based on original element subscripts and the reference window width; setting element values corresponding to remaining extended element subscripts in the initial extended RDM matrix to a set value, to obtain a filled extended RDM matrix.

5. The method of claim 1, wherein, The method further includes determining a constant false alarm detection threshold of the detected cell according to element values of matrix elements contained in the reference window region and the protection window region. The method further includes determining reference matrix elements only in the reference window region according to element subscripts of matrix elements contained in the reference window region and the protection window region. The method further includes obtaining a number of element values of the reference matrix elements and reference element values of the reference matrix elements. The method further includes determining an average noise power of the reference window region based on the number of element values and the reference element values. The method further includes obtaining the constant false alarm detection threshold of the detected cell according to the average noise power and a given threshold relationship.

6. The method of claim 1, wherein, The method further includes determining a constant false alarm detection result of the detected cell according to the constant false alarm detection threshold. The method further includes obtaining a matrix element value of the detected cell from the RDM matrix. If the matrix element value is greater than or equal to the constant false alarm detection threshold, the constant false alarm detection result is determined to be that the detected cell is a target cell; otherwise, the constant false alarm detection result is determined to be that the detected cell is a non-target cell.

7. A constant-false-alarm detection apparatus characterized by comprising: The method further includes: an original signal processing module configured to process original signals collected by a millimeter wave radar to obtain a range Doppler spectrum (RDM) matrix of a collection environment in which the millimeter wave radar is located; a window region forming module configured to determine a window geometry of a detected cell in the RDM and form a reference window region and a protection window region having the window geometry with respect to the detected cell, the detected cell being a matrix element in the RDM matrix; a detection threshold determining module configured to determine a constant false alarm detection threshold of the detected cell according to element values of matrix elements contained in the reference window region and the protection window region; a detection result determining module configured to determine a constant false alarm detection result of the detected cell according to the constant false alarm detection threshold. The window region forming module includes: an element subscript obtaining unit configured to take a set diamond shape as the window geometry of the detected cell and obtain element subscripts of the detected cell; a matrix extension processing unit configured to perform extension processing on the RDM matrix based on the reference window width to obtain an extended RDM matrix, wherein the difference between the horizontal and vertical subscript values of the extended element subscript corresponding to the detected cell in the extended RDM matrix and the given reference window width is positive; a protection window constructing unit configured to take the detected cell as a center point and combine a given protection window width to enclose matrix elements having the diamond shape from the extended RDM matrix to construct a protection window region. The reference window constructing unit is configured to take the unit under test as a center point, and to define the matrix elements with the diamond shape from the extended RDM matrix to form a reference window region in combination with a given reference window width. 8.An electronic device, comprising: at least one processor; and a memory connected with the at least one processor in communication; wherein the memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor to enable the at least one processor to perform the constant false alarm rate detection method of any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, The computer readable storage medium stores computer instructions for causing the processor to implement the constant false alarm rate detection method of any one of claims 1-6 when executed.

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