Nested virtual array grating lobe cancellation method based on overlapping antenna compensation

Abstract

The application discloses a nested virtual array grating lobe elimination method based on overlapping antenna compensation, a MIMO virtual array radar, a controller and a computer storage medium, wherein the method comprises the following steps: acquiring virtual array elements in a virtual array, the virtual array elements comprising a plurality of transceiving antenna groups with virtual channel overlap, the transceiving antenna groups comprising receiving antennas and transmitting antennas; calculating target phase differences of each transmitting antenna and receiving antenna in the plurality of virtual array elements; obtaining a phase compensation value according to the plurality of target phase differences; and performing virtual channel compensation processing on the virtual array according to the phase compensation value. In the case where the approximate condition that the target reflected wave is a plane wave does not hold, the application sets overlapping antennas in the virtual array of the MIMO virtual array radar, calculates the phase compensation value by using the overlapping antennas, and performs virtual channel phase compensation, so that the purpose of reducing or even eliminating the grating lobe is achieved, and the accuracy of target detection of the radar is improved.

Description

Technical Field

[0001] This application relates to the field of signal processing technology, specifically to a nested virtual array grating lobe elimination method based on overlapping antenna compensation, a MIMO virtual array radar, a controller, and a computer storage medium. Background Technology

[0002] In existing technologies, MIMO virtual channel technology can multiply the actual number of radar transmit and receive channels, and has extremely wide applications in application fields with high cost requirements, such as automotive radar and traffic radar. As users have increasingly higher requirements for the number of channels and radar aperture, the number of virtual array elements in MIMO virtual array radar can reach thousands. With the increase in the number of array elements and the increase in radar aperture, it means that the radar's ability to distinguish targets is improved. In particular, traditional MIMO virtual channel technology makes far-field condition assumptions on the radar reflected waves to simplify the processing, that is, it performs target detection by approximating the radar reflected waves as plane waves.

[0003] However, as the radar space increases and the radar aperture enlarges, the assumption of the radar's far-field condition will no longer be satisfied. That is, the approximate condition of the target reflected wave as a plane wave will no longer be satisfied. If the target detection is still performed according to the far-field condition approximation, the accuracy will decrease as the radar gets closer to the target. Moreover, the nested array design of the transmitting and receiving antennas based on this will bring about the grating lobe effect, which will seriously affect the accuracy of the radar in target detection. Summary of the Invention

[0004] This application provides a nested virtual array grating lobe elimination method based on overlapping antenna compensation, a MIMO virtual array radar, a controller, and a computer storage medium. It can at least ensure that the solution of this application can perform phase compensation on the virtual channel, suppress the nested virtual array grating lobes, thereby eliminating the grating lobe effect caused by the failure of the far-field condition assumption, and improving the accuracy of radar target detection.

[0005] In a first aspect, embodiments of this application provide a nested virtual array grating lobe cancellation method based on overlapping antenna compensation, the method being applied to MIMO virtual array radar, the method comprising: Obtain virtual array elements in a virtual array, wherein the virtual array elements include multiple transceiver antenna groups with overlapping virtual channels, and the transceiver antenna groups include receiving antennas and transmitting antennas; Calculate the target phase difference between each of the transmitting antennas and the receiving antennas in the plurality of virtual array elements; A phase compensation value is obtained based on the phase differences of the multiple targets; The virtual channels of the virtual array are compensated according to the phase compensation value.

[0006] In some embodiments, obtaining the phase compensation value based on the plurality of target phase differences includes: Based on the multiple target phase differences, the virtual array element generates multiple transmit / receive phase differences from multiple transmit / receive antenna groups. The overlapping phase difference of the virtual array elements is obtained based on the multiple transmit and receive phase differences; The phase compensation value is obtained based on the overlapping phase difference of the multiple virtual array elements.

[0007] In some embodiments, calculating the target phase difference between each of the transmitting antennas and the receiving antennas in the plurality of virtual array elements includes: Generate the straight-line distance expressions from the virtual channels corresponding to the transmitting antenna and the receiving antenna to the target; The straight-line distance expression is subjected to Taylor expansion to obtain the Fresnel approximation expression; The target phase difference from the virtual channel corresponding to the transmitting antenna and the receiving antenna is calculated based on the Fresnel approximation expression.

[0008] In some embodiments, obtaining multiple transmit / receive phase differences generated by multiple transmit / receive antenna groups for the virtual array element based on multiple target phase differences includes: Subtracting the target phase difference of the receiving antenna from the target phase difference of the transmitting antenna yields the corresponding transmit / receive phase difference of the transmit / receive antenna group. The virtual array element includes at least two of the transceiver antenna groups.

[0009] In some embodiments, the virtual array element includes a first transceiver antenna group and a second transceiver antenna group, and obtaining the overlapping phase difference of the virtual array element based on the plurality of transceiver phase differences includes: Subtracting the transmit / receive phase difference of the second transmit / receive antenna group from the transmit / receive phase difference of the first transmit / receive antenna group yields the overlapping phase difference of the virtual array elements. The virtual array includes at least two virtual array elements.

[0010] In some embodiments, the virtual array includes a first virtual array element and a second virtual array element, and obtaining a phase compensation value based on the overlapping phase difference of the plurality of virtual array elements includes: Subtract the overlapping phase difference of the second virtual array element from the overlapping phase difference of the first virtual array element to obtain the phase compensation value expression; Obtain the actual antenna spacing of the MIMO virtual array radar; Substituting the actual antenna spacing into the phase compensation value expression yields the phase compensation value.

[0011] In some embodiments, prior to acquiring the virtual array elements in the virtual array, the method includes: The MIMO virtual array radar is controlled to perform virtual array settings so that the virtual channels of the receiving antenna and the transmitting antenna overlap.

[0012] Secondly, this application provides a MIMO virtual array radar, 8. The MIMO virtual array radar includes a virtual array generation module, a phase compensation value calculation module, and a virtual channel compensation module; The virtual array generation module is used to generate and obtain virtual array elements in the virtual array. The virtual array elements include multiple transceiver antenna groups with overlapping virtual channels. The transceiver antenna groups include receiving antennas and transmitting antennas. The phase compensation value calculation module is used to calculate the target phase difference between each of the transmitting antennas and the receiving antennas in the plurality of virtual array elements, and to obtain the phase compensation value based on the plurality of target phase differences; The virtual channel compensation module is used to perform virtual channel compensation processing on the virtual array based on the phase compensation value.

[0013] Thirdly, embodiments of this application provide a controller, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the nested virtual array lobe elimination method based on overlapping antenna compensation as described in any embodiment of the first aspect.

[0014] Fourthly, embodiments of this application provide a computer-readable storage medium storing computer-executable instructions for performing the nested virtual array grating lobe elimination method based on overlapping antenna compensation as described in any embodiment of the first aspect.

[0015] This application has at least the following beneficial effects: This application proposes a nested virtual array grating lobe elimination method based on overlapping antenna compensation. It obtains virtual array elements in a virtual array, each virtual array element including multiple transceiver antenna groups with overlapping virtual channels. Each transceiver antenna group includes a receiving antenna and a transmitting antenna. The method calculates the target phase difference between each transmitting antenna and the receiving antenna in each of the multiple virtual array elements. A phase compensation value is obtained based on the multiple target phase differences. The virtual channel of the virtual array is then compensated based on the phase compensation value. Specifically, when the far-field conditions are not met, this invention uses overlapping antennas in the virtual array of a MIMO virtual array radar to calculate the phase compensation value and perform virtual channel phase compensation, thereby reducing or even eliminating grating lobes. This overcomes the problem in the prior art where the radar reflected wave is designed according to far-field conditions, resulting in a grating lobe effect that affects the target detection accuracy in the spatial dimension. Attached Figure Description

[0016] Figure 1 This is a flowchart of a nested virtual array grating lobe elimination method based on overlapping antenna compensation proposed in an embodiment of this application; Figure 2 This is a schematic diagram of the far field of a one-dimensional uniform linear array when the far field conditions are met, as proposed in another embodiment of this application. Figure 3 A near-field schematic diagram of a one-dimensional uniform linear array when the far-field condition is not met, as proposed in another embodiment of this application; Figure 4 This is a flowchart illustrating the process of obtaining phase compensation values ​​based on multiple target phase differences in a nested virtual array lobe elimination method based on overlapping antenna compensation, as proposed in another embodiment of this application. Figure 5 A diagram of an actual MIMO transceiver array using a nested virtual array design scheme between transceivers, as proposed in another embodiment of this application; Figure 6 As proposed in another embodiment of this application, Figure 5 Virtual array element layout diagram of the transceiver array; Figure 7 This is a schematic diagram of the horizontal Fourier transform spectrum proposed in another embodiment of this application, used to express... Figure 6 The Fourier transform spectrum of the received signal from the virtual array shows the presence of side lobes with gaps at the array edges. Figure 8 This is a schematic diagram of the horizontal Fourier transform spectrum proposed in another embodiment of this application, used to express... Figure 6 The Fourier transform spectrum of the virtual array after discarding edge elements shows the side lobes and grating lobes after removing the gaps at the array edges; Figure 9 This is a schematic diagram of the horizontal Fourier transform spectrum proposed in another embodiment of this application, used to express... Figure 6 The Fourier transform spectrum of the virtual array after discarding edge elements and performing phase compensation shows the grating lobe situation after processing; Figure 10 This is a structural diagram of a controller proposed in another embodiment of this application. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0018] In some embodiments, although functional modules are divided in the system diagram and a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the system or the order in the flowchart. The terms "first," "second," etc., in the specification, claims, and the foregoing drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0019] Furthermore, unless otherwise explicitly specified and limited, the term "connection / linkage" should be interpreted broadly, for example, it can be a fixed connection or a movable connection, a detachable connection or a non-detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection or a connection that can communicate with each other; it can be a direct connection or an indirect connection through an intermediate medium.

[0020] In the description of the embodiments of this invention, the terms "one embodiment / implementation," "another embodiment / implementation," or "some embodiments / implementations," "in the above embodiments / implementations," etc., refer to specific features, structures, materials, or characteristics described in conjunction with embodiments or examples that are included in at least two embodiments or implementations disclosed in this invention. In this disclosure, the illustrative expressions of the above terms do not necessarily refer to the same illustrative embodiment or implementation. It should be noted that although a logical order is shown in the flowcharts, in some cases, the steps shown or described may be performed in a different order than that shown in the flowcharts.

[0021] Currently, MIMO (multiple-in multiple-out) virtual channel technology can multiply the actual number of radar transmit and receive channels, and has extremely wide applications in cost-sensitive fields such as automotive radar and traffic radar. As users demand higher channel numbers and radar apertures, the number of virtual array elements in MIMO virtual array radars can reach thousands. With the increase in the number of array elements and the increase in radar aperture, the radar's target resolution capability is improved. Traditional MIMO virtual channel technology simplifies the processing by making far-field condition assumptions about the radar's reflected waves, that is, by approximating the radar reflected waves as plane waves for target detection. However, as the radar space increases and the radar aperture increases, the far-field condition assumptions of the radar no longer hold, that is, the approximation condition of the target reflected wave as a plane wave is no longer satisfied. If target detection is still performed according to the far-field condition approximation, the accuracy will decrease as the radar gets closer to the target. Moreover, the nested array design of transmit and receive antennas will introduce grating lobe effects, which will seriously affect the accuracy of radar target detection.

[0022] The current MIMO virtual channel technology has the following problems: 1) For MIMO virtual array radar, when the far-field conditions are no longer met, the radar reflected wave is approximated according to the classical far-field conditions. Nested virtual array design will bring about grating lobe problems, thus affecting the detection of targets in the spatial dimension.

[0023] To at least address the aforementioned problems, this application proposes a nested virtual array grating lobe elimination method based on overlapping antenna compensation. This method involves acquiring virtual array elements in a virtual array, each virtual element comprising multiple overlapping transmit and receive antenna groups, each containing a receiving antenna and a transmitting antenna. The method calculates the target phase difference between each transmit and receive antenna in the multiple virtual array elements, obtains a phase compensation value based on these phase differences, and then performs virtual channel compensation processing on the virtual array based on this phase compensation value. Specifically, when far-field conditions are not met, this invention utilizes overlapping antennas within the virtual array of a MIMO virtual array radar to calculate the phase compensation value and perform virtual channel phase compensation, thereby reducing or even eliminating grating lobes. This overcomes the problem in existing technologies where the radar reflected wave is approximated using the classical non-planar wave approximation, leading to grating lobe effects in nested virtual array design, which negatively impacts target detection accuracy in the spatial dimension.

[0024] The embodiments of this application will be further described below with reference to the accompanying drawings.

[0025] refer to Figure 1 , Figure 1 This is a flowchart of a nested virtual array grating lobe elimination method based on overlapping antenna compensation proposed in one embodiment of this application; in some embodiments, the nested virtual array grating lobe elimination method based on overlapping antenna compensation is applied to MIMO virtual array radar, and the method includes at least the following steps: Step S110: Obtain virtual array elements in the virtual array. The virtual array elements include multiple transceiver antenna groups with overlapping virtual channels. The transceiver antenna groups include receiving antennas and transmitting antennas. Step S120: Calculate the target phase difference between each transmitting antenna and receiving antenna in the multiple virtual array elements; Step S130: Obtain phase compensation values ​​based on the phase differences of multiple targets; Step S140: Perform virtual channel compensation processing on the virtual array based on the phase compensation value.

[0026] Among them, reference Figure 2 , Figure 2 This is a schematic diagram of the far-field condition of a one-dimensional uniform linear array proposed in an embodiment of this application. When the radar aperture is much smaller than the distance to the target, its wavefront is approximately a plane wave incident. Therefore, a plane wave assumption is made for the wavefront of the reflected echo, and the electromagnetic wave paths incident on each array element are considered parallel; specifically, as shown... Figure 2As shown, the transmitting and receiving wavefronts of its electromagnetic waves are a single plane, and the electromagnetic waves transmitted and received by each channel are parallel to each other. The phase difference of the receiving channel is determined by the incident angle. The phase difference between the channels is as shown in formula (1).

[0027] , formula (1) in, Angle of incidence Let π be the mathematical constant pi, and d be the spacing between array elements. The wavelength of electromagnetic waves, This represents the phase difference between channels.

[0028] It is conceivable that since the phase difference obtained by the above formula (1) is calculated on the basis that the electromagnetic waves transmitted and received by each channel are parallel to each other, as the radar aperture increases, when the radar aperture is no longer much smaller than the distance to the target, the radar reflected wave will bring about the grating lobe effect when nested virtual array design according to the far-field condition assumption, which will lead to a large error in the detection accuracy of the target in the spatial dimension. Therefore, this application starts from the fact that the far-field condition is not met, and attempts to eliminate the above grating lobe effect by calculating the phase compensation value and performing virtual channel phase compensation.

[0029] refer to Figure 3 , Figure 3 This is a near-field schematic diagram of a one-dimensional uniform linear array when the far-field condition is not met, as proposed in another embodiment of this application. The reflection path from the target to each array element is no longer approximated by parallel incidence. The path of each channel is determined by the straight-line distance from the array's transceiver element to the target, and the exact formula is as follows: , formula (2) in, Indicates the first There are n targets, where n represents the nth array element, and d represents the element spacing. , This represents the azimuth and distance of the target from the array center 0. For the first The phase difference between the nth target and the nth array element.

[0030] Using the above formula (2), this application can obtain the phase difference of the virtual channels corresponding to each receiving antenna and transmitting antenna in the virtual array element at the target distance. At the same time, since there are multiple transmitting and receiving antenna groups with overlapping array element positions after array virtualization in this application, the multiple transmitting and receiving antenna groups are different transmitting and receiving channel combinations, including receiving antennas and transmitting antennas. After calculating the target phase difference of each transmitting antenna and receiving antenna in the multiple virtual array elements, the phase compensation value of each virtual channel can be obtained by overlapping antenna phase difference. The virtual channel compensation processing of the virtual array is performed according to the phase compensation value to achieve the effect of compensating for the approximate error caused by the failure to meet the far-field conditions, thereby eliminating the grating lobe effect caused by it.

[0031] In some embodiments, according to steps S110 to 140 above, this application provides a method for eliminating nested virtual array grating lobes using overlapping antenna compensation. In the virtual array, virtual channels with overlapping positions are set, and path compensation values ​​are calculated using overlapping antennas. Then, virtual channel phase compensation is performed to reduce or even eliminate grating lobes, which can effectively improve the accuracy of radar target detection.

[0032] refer to Figure 4 , Figure 4 In another embodiment of the nested virtual array grating lobe cancellation method based on overlapping antenna compensation proposed in this application, a flowchart of constructing the Discrete Fourier Transform (DFT) matrix and the standard Discrete Fourier Transform (DFT) matrix is ​​provided. In some embodiments, constructing the Discrete Fourier Transform (DFT) matrix and the standard Discrete Fourier Transform (DFT) matrix based on the signal to be processed includes at least the following steps: Step S410: Based on the multiple target phase differences, obtain the multiple transmit / receive phase differences generated by the multiple transmit / receive antenna groups for the virtual array element; Step S420: Obtain the overlapping phase difference of the virtual array elements based on multiple transmit and receive phase differences; Step S430: Obtain the phase compensation value based on the overlapping phase difference of multiple virtual array elements.

[0033] In some embodiments, calculating the target phase difference between each transmitting antenna and receiving antenna in a plurality of virtual array elements includes: generating a straight-line distance expression from the virtual channel corresponding to the transmitting antenna and receiving antenna to the target; performing Taylor expansion on the straight-line distance expression to obtain a Fresnel approximation expression; and calculating the target phase difference from the target to the virtual channel corresponding to the transmitting antenna and receiving antenna based on the Fresnel approximation expression.

[0034] Specifically, by performing a Taylor expansion on formula (2) and taking the first two terms, we can obtain the Fresnel approximation formula (3).

[0035] , formula (3) As can be seen from formula (3), when performing plane wave approximation in this application embodiment, only the first term is retained; if the array element aperture increases, a second term needs to be added for a more accurate approximation. In this application embodiment, the second term of formula (3) is denoted as... The second term of formula (3) is the phase compensation value obtained based on the phase difference of multiple targets. By eliminating the first term in formula (3) through the phase difference process from step S410 to S430, the value of the second term can be indirectly obtained, thereby obtaining the phase compensation value of each virtual channel. Phase compensation is performed according to the device to eliminate the grating lobe effect.

[0036] In some embodiments, specifically, refer to Figure 5 ,by Figure 5 Taking a one-dimensional horizontal array as an example, the circular icon represents a receiving antenna, the square icon represents a receiving antenna, the number of receiving antennas is 24, the receiving antennas are evenly arranged, and the antenna spacing is 3d, where d is half of the carrier wavelength; the number of transmitting antennas is 6, the first three (TX1, TX2, TX3) and the last three (TX4, TX5, TX6) are evenly arranged, and the spacing is 2d; the spacing between TX3 and TX4 is 66d; for the sake of generality, the arrangement of the transmitting and receiving antennas in the embodiments of this application is not on the same horizontal line.

[0037] refer to Figure 5 , Figure 6 and Figure 8 , Figure 5 The actual antenna array for transmitting and receiving antennas, and the array virtualized after MIMO, are as follows: Figure 6 As shown. The virtualized antenna array aperture reaches 144d. This is because the virtual array has apertures at elements 71 and 74 (…). Figure 6 The overlap occurs at the gray icon (in the middle), generated by combinations of (TX3, TX40) and (RX1, RX23) and (RX2, RX24), respectively. It can be seen that the virtual array aperture is not 146d. Furthermore, there is an element gap at each edge of the virtual array, allowing the first and last elements to be discarded in subsequent processing to suppress the sidelobe rise caused by these gaps. Assume the target is 20 meters from the radar, with a speed of 50 m / s and a horizontal azimuth of 0°. Figure 7 For the target's Fourier transform spectrum in the horizontal direction, side lobes resembling "bird wings" appear on both sides of the target peak. The two peaks on the "wings" are grating lobes caused by model errors due to the array not meeting the far-field conditions. After discarding the gaps in the array elements at the edges, its Fourier transform spectrum is as follows: Figure 8 As shown.

[0038] In some embodiments, the specific process of calculating the target phase difference from the virtual channel corresponding to the transmitting and receiving antennas according to the Fresnel approximation is as follows: Assuming that the virtualized VX1 array element is taken as the origin of the coordinate system, the virtual array element VX71 is generated by the combination of TX3, RX23 and TX4, RX1; the virtual array element VX74 is generated by the combination of TX3, RX24 and TX4, RX2. According to formula (3), the phase difference from the target to the overlapping VX71 array element can be calculated as follows: Phase difference between target and TX3: (4) Phase difference from target to TX4: (5) Phase difference between target and RX1: (6) Phase difference between target and RX2: (7) Phase difference between the target and the RX23: (8) Phase difference between the target and the RX24: (9) Formulas (4) to (9) above are the target phase differences from the target to the virtual channels corresponding to the transmitting and receiving antennas, obtained according to the Fresnel approximation, where n represents the nth array element, and the subscript indicates the specific transmitting and receiving antenna. , This represents the azimuth and distance of the target from the array origin 0. The subscript indicates the specific transmitting and receiving antenna, representing the phase difference from the target to the nth array element.

[0039] In some embodiments, multiple transmit / receive phase differences generated by multiple transmit / receive antenna groups for a virtual array element are obtained based on multiple target phase differences, including: subtracting the target phase difference of the receiving antenna from the target phase difference of the transmitting antenna to obtain the transmit / receive phase difference of the corresponding transmit / receive antenna group; wherein, the virtual array element includes at least two transmit / receive antenna groups, and specifically, based on the target phase differences in formulas (4) to (9) above, the transmit / receive phase differences of each transmit / receive antenna group are obtained as follows: The transmit / receive phase difference generated by TX3 and RX23 in the virtual array element VX71 : , formula (10) The transmit / receive phase difference generated by TX4 and RX1 in the virtual array element VX71 : , formula (11) The virtual array element VX74 generates a transmit / receive phase difference from TX3 and RX24. : , formula (12) The transmit / receive phase difference generated by TX4 and RX2 in the virtual array element VX74 : , formula (13) Formulas (10) to (13) above are the transmit and receive phase differences of the corresponding transmit and receive antenna groups obtained by subtracting the target phase difference of the receiving antenna from the target phase difference of the transmitting antenna.

[0040] In some embodiments, the virtual array element includes a first transceiver antenna group and a second transceiver antenna group. The overlapping phase difference of the virtual array element is obtained based on multiple transceiver phase differences, including: subtracting the transceiver phase difference of the second transceiver antenna group from the transceiver phase difference of the first transceiver antenna group to obtain the overlapping phase difference of the virtual array element; wherein, the virtual array includes at least two virtual array elements; specifically, the overlapping phase difference of the virtual array element is obtained based on the transceiver phase differences in the above formulas (10) to (13) as follows: Subtracting formula (10) from formula (11) yields the phase difference of the overlapping virtual array element VX71. As shown in formula (14):

[0041] , formula (14) Subtracting formula (12) from formula (13) yields the phase difference of the overlapping virtual array element VX74. As shown in formula (15):

[0042] , formula (15) Formulas (14) to (15) above are the multiple overlapping phase differences of the virtual array elements obtained by subtracting the phase difference between the first and second transceiver antenna groups from the phase difference between the first and second transceiver antenna groups.

[0043] In some embodiments, the virtual array includes a first virtual array element and a second virtual array element. A phase compensation value is obtained based on the overlapping phase difference of multiple virtual array elements, including: subtracting the overlapping phase difference of the second virtual array element from the overlapping phase difference of the first virtual array element to obtain a phase compensation value expression; obtaining the actual antenna spacing of the MIMO virtual array radar; and substituting the actual antenna spacing into the phase compensation value expression to obtain the phase compensation value. Specifically, based on the overlapping phase difference in formulas (14) to (15) above, the phase compensation value expression is obtained as follows: Subtract formula (14) from formula (15), as shown in formula (16): , formula (16) Substituting the actual antenna spacing into formula (16) and simplifying, the phase difference can be obtained. We can obtain the second term of formula (3). As shown in formula (17): , formula (17) In summary, this application can perform phase compensation of the virtual channel according to formula (17) before angle measurement of the target, so that the grating lobe in the horizontal Fourier transform spectrum of the target can be well suppressed. If there is a slight residual grating lobe, it is caused by the Doppler effect of the target. Usually, the grating lobe is already submerged under the noise floor in the actual measurement. Figure 9 As shown, Figure 9 This is a schematic diagram of the horizontal Fourier transform spectrum proposed in another embodiment of this application, used to express... Figure 6 The Fourier transform spectrum of the virtual array after discarding edge elements and performing phase compensation shows the grating lobe situation after processing.

[0044] In some embodiments, the nested virtual array grating lobe elimination method based on overlapping antenna compensation in this application is also applicable to planar arrays. Only the vertical grating lobe effect can be eliminated by compensating in the same way in the vertical direction, thereby improving the accuracy of radar target detection.

[0045] In some embodiments, before obtaining the virtual array elements in the virtual array, the method includes: controlling the MIMO virtual array radar to perform virtual array settings so that the virtual channels of the receiving antenna and the transmitting antenna overlap. It is conceivable that this application sets up virtual channels with overlapping positions when creating the virtual array, and then obtains the phase compensation value for virtual channel compensation in subsequent steps by canceling phase difference terms of the overlapping antennas.

[0046] The second aspect of this application provides a MIMO virtual array radar, which includes a virtual array generation module, a phase compensation value calculation module, and a virtual channel compensation module. The virtual array generation module is used to generate and acquire virtual array elements in the virtual array. The virtual array elements include multiple transceiver antenna groups with overlapping virtual channels, and the transceiver antenna groups include receiving antennas and transmitting antennas. The phase compensation value calculation module is used to calculate the target phase difference between each transmitting antenna and receiving antenna in the multiple virtual array elements, and obtain a phase compensation value based on the multiple target phase differences. The virtual channel compensation module is used to perform virtual channel compensation processing on the virtual array based on the phase compensation value.

[0047] In some embodiments, the MIMO virtual array radar conforms to the operating environment for the nested virtual array grating lobe elimination method based on overlapping antenna compensation of any of the above embodiments, so that the MIMO virtual array radar has the functions and effects of the nested virtual array grating lobe elimination method based on overlapping antenna compensation of any of the above embodiments.

[0048] refer to Figure 10 , Figure 10 This is a schematic diagram of the controller provided in an embodiment of the present invention.

[0049] Some embodiments of the present invention provide a controller, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the nested virtual array lobe cancellation method based on overlapping antenna compensation according to any of the above embodiments, for example, executing the above-described method. Figure 1 Method steps S110 to S140, Figure 4 Method steps S410 to S430.

[0050] The controller 1000 of this embodiment includes one or more processors 1010 and a memory 1020. Figure 10 The example uses a processor 1010 and a memory 1020.

[0051] The processor 1010 and the memory 1020 can be connected via a bus or other means. Figure 10 Taking the example of a connection between China and Israel via a bus.

[0052] Memory 1020, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. Furthermore, memory 1020 may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, memory 1020 may optionally include memory 1020 remotely located relative to processor 1010. These remote memories can be connected to controller 1000 via a network, and examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0053] In some embodiments, when the processor executes a computer program, it executes the nested virtual array lobe elimination method based on overlapping antenna compensation of any of the above embodiments at preset intervals.

[0054] Those skilled in the art will understand that Figure 10 The device structure shown does not constitute a limitation on the controller 1000 and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0055] exist Figure 10 In the controller 1000 shown, the processor 1010 can be used to call the nested virtual array grating lobe elimination method based on overlapping antenna compensation stored in the memory 1020, thereby realizing the nested virtual array grating lobe elimination method based on overlapping antenna compensation.

[0056] Based on the hardware structure of the controller 1000 described above, various embodiments of the MIMO virtual array radar of the present invention are proposed. Meanwhile, the non-transient software program and instructions required to implement the nested virtual array grating lobe elimination method based on overlapping antenna compensation of the above embodiments are stored in memory. When executed by the processor, the nested virtual array grating lobe elimination method based on overlapping antenna compensation of the above embodiments is executed.

[0057] Furthermore, embodiments of the present invention also provide a MIMO virtual array radar, which includes the controller described above.

[0058] In some embodiments, since the MIMO virtual array radar of the present invention has the controller of the above embodiments, and the controller of the above embodiments is capable of executing the nested virtual array grating lobe elimination method based on overlapping antenna compensation of the above embodiments, the specific implementation and technical effects of the MIMO virtual array radar of the present invention can refer to the specific implementation and technical effects of the nested virtual array grating lobe elimination method based on overlapping antenna compensation of any of the above embodiments. When the approximate condition of the target reflected wave as a plane wave is not met, by setting overlapping antennas in the virtual array of the MIMO virtual array radar, the phase compensation value is calculated using the overlapping antennas, and virtual channel phase compensation is performed, thereby achieving the purpose of reducing or even eliminating grating lobes and improving the accuracy of radar target detection.

[0059] This invention also provides a computer-readable storage medium storing computer-executable instructions for executing the aforementioned nested virtual array grating lobe elimination method based on overlapping antenna compensation. For example, the computer-executable instructions can cause one or more processors to execute the nested virtual array grating lobe elimination method based on overlapping antenna compensation described above, and perform the above-described... Figure 1 Method steps S110 to S140, Figure 4 Method steps S410 to S430.

[0060] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; that is, they may be located in one place or distributed across multiple network nodes. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0061] It will be understood by those skilled in the art that all or some of the steps and systems in the methods disclosed above can be implemented as software, firmware, hardware, and suitable combinations thereof. Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, which can include computer-readable storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term computer-readable storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer-readable storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, as is known to those skilled in the art, communication media typically contain computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

[0062] The above is a detailed description of the preferred embodiments of this application. However, this application is not limited to the above embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of this application. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A nested virtual array lobe elimination method based on overlapping antenna compensation, characterized in that, The method is applied to MIMO virtual array radar, and the method includes: Obtain virtual array elements in a virtual array, wherein the virtual array elements include multiple transceiver antenna groups with overlapping virtual channels, and the transceiver antenna groups include receiving antennas and transmitting antennas; Calculate the target phase difference between each of the transmitting antennas and the receiving antennas in the plurality of virtual array elements; A phase compensation value is obtained based on the phase differences of the multiple targets; The virtual channels of the virtual array are compensated according to the phase compensation value; The calculation of the target phase difference between each of the transmitting antennas and the receiving antennas in the plurality of virtual array elements includes: Generate the straight-line distance expressions from the virtual channels corresponding to the transmitting antenna and the receiving antenna to the target; The straight-line distance expression is subjected to Taylor expansion to obtain the Fresnel approximation expression; The target phase difference from the virtual channel corresponding to the transmitting antenna and the receiving antenna is calculated based on the Fresnel approximation expression.

2. The nested virtual array grating lobe elimination method based on overlapping antenna compensation according to claim 1, characterized in that, The step of obtaining the phase compensation value based on the multiple target phase differences includes: Based on the multiple target phase differences, the virtual array element generates multiple transmit / receive phase differences from multiple transmit / receive antenna groups. The overlapping phase difference of the virtual array elements is obtained based on the multiple transmit and receive phase differences; The phase compensation value is obtained based on the overlapping phase difference of the multiple virtual array elements.

3. The nested virtual array grating lobe elimination method based on overlapping antenna compensation according to claim 2, characterized in that, The step of obtaining multiple transmit / receive phase differences generated by multiple transmit / receive antenna groups for the virtual array element based on multiple target phase differences includes: Subtracting the target phase difference of the receiving antenna from the target phase difference of the transmitting antenna yields the corresponding transmit / receive phase difference of the transmit / receive antenna group. The virtual array element includes at least two of the transceiver antenna groups.

4. The nested virtual array grating lobe elimination method based on overlapping antenna compensation according to claim 2, characterized in that, The virtual array element includes a first transceiver antenna group and a second transceiver antenna group. The step of obtaining the overlapping phase difference of the virtual array element based on the plurality of transceiver phase differences includes: Subtracting the transmit / receive phase difference of the second transmit / receive antenna group from the transmit / receive phase difference of the first transmit / receive antenna group yields the overlapping phase difference of the virtual array elements. The virtual array includes at least two virtual array elements.

5. The nested virtual array lobe elimination method based on overlapping antenna compensation according to claim 2, characterized in that, The virtual array includes a first virtual array element and a second virtual array element. The step of obtaining a phase compensation value based on the overlapping phase difference of the plurality of virtual array elements includes: Subtract the overlapping phase difference of the second virtual array element from the overlapping phase difference of the first virtual array element to obtain the phase compensation value expression; Obtain the actual antenna spacing of the MIMO virtual array radar; Substituting the actual antenna spacing into the phase compensation value expression yields the phase compensation value.

6. The nested virtual array lobe elimination method based on overlapping antenna compensation according to claim 1, characterized in that, Before acquiring the virtual array elements in the virtual array, the method includes: The MIMO virtual array radar is controlled to perform virtual array settings so that the virtual channels of the receiving antenna and the transmitting antenna overlap.

7. A MIMO virtual array radar, characterized in that, The MIMO virtual array radar includes a virtual array generation module, a phase compensation value calculation module, and a virtual channel compensation module. The virtual array generation module is used to generate and obtain virtual array elements in the virtual array. The virtual array elements include multiple transceiver antenna groups with overlapping virtual channels. The transceiver antenna groups include receiving antennas and transmitting antennas. The phase compensation value calculation module is used to calculate the target phase difference between each of the transmitting antennas and the receiving antennas in the plurality of virtual array elements, and to obtain the phase compensation value based on the plurality of target phase differences; The virtual channel compensation module is used to perform virtual channel compensation processing on the virtual array according to the phase compensation value; The calculation of the target phase difference between each of the transmitting antennas and the receiving antennas in the plurality of virtual array elements includes: Generate the straight-line distance expressions from the virtual channels corresponding to the transmitting antenna and the receiving antenna to the target; The straight-line distance expression is subjected to Taylor expansion to obtain the Fresnel approximation expression; The target phase difference from the virtual channel corresponding to the transmitting antenna and the receiving antenna is calculated based on the Fresnel approximation expression.

8. A controller, characterized in that, The method includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the nested virtual array lobe elimination method based on overlapping antenna compensation as described in any one of claims 1 to 6.

9. A computer-readable storage medium storing computer-executable instructions for performing the nested virtual array grating lobe elimination method based on overlapping antenna compensation as described in any one of claims 1 to 6.

Images