Virtual subarray-based phased array antenna anti-jamming receiving system and design method

Abstract

The application discloses a virtual-subarray-based phased array antenna anti-interference receiving system and a design method, belongs to the technical field of adaptive digital beam forming processing, and comprises a phased array antenna; the phased array antenna comprises a plurality of subarrays, the subarrays are regarded as antennas, and each subarray generates a signal through analog synthesis; after each subarray analog synthesis signal is subjected to frequency conversion and sampling, a digital signal is obtained; adaptive beam forming is realized through digital beam forming and MVDR algorithm for the plurality of subarray signals, and interference signals are suppressed. According to the application, the planar phased array antenna is divided through virtual subarrays, and subarray-level signal synthesis processing is adopted, so that the scale of frequency conversion and sampling circuits of independent receiving channels is greatly reduced, and the suppression of interference direction signals is realized in combination with the MVDR algorithm.

Description

Technical Field

[0001] This invention relates to the field of adaptive digital beamforming technology, and more specifically, to a phased array antenna anti-interference receiving system and design method based on virtual subarrays. Background Technology

[0002] With the development of electronic reconnaissance and countermeasures technologies, the working environment of forward communication links for missile and other weapon platforms is becoming increasingly harsh. In order to ensure the normal operation of forward communication links, the forward communication link processing system needs to have strong anti-jamming capabilities.

[0003] Adaptive beamforming is an important spatial filtering and anti-interference technique. Adaptive beamforming based on the Minimum Variance Distortionless Response (MVDR) algorithm has moderate algorithm complexity and good stability, achieving good results at the desired signal azimuth angle. Given the known circumstances, it possesses high engineering value.

[0004] Taking the incident signal of K far-field narrowband signals onto a uniform linear array of M elements as an example, this paper illustrates the principle of digital beamforming technology based on the minimum variance distortionless response (MVDR) algorithm. Figure 1 As shown, the spatial domain filter output is:

[0005] y(n)=w H x(n)

[0006] Where w is the weight vector of the spatial domain filter, and w = [ω0 ω1 … ω M-1 ] T The array-received signal x(n) is the input signal vector of the spatial filter.

[0007] x(n) = [x0(n) x1(n) … x M-1 (n)] T

[0008] = AS(n) + v(n)

[0009] The average output power P(θ) is:

[0010] P(θ)=E{|y(n| 2}=E{w H x(n)x H w(n)}=w H Rw

[0011] Where R = E{x(n)x H} is the spatial autocorrelation matrix.

[0012] Assuming the desired signal s0(n) is incident from the direction θ0, and the received signal in that direction by the array antenna is x0(n) = a(θ0)s0(n), to ensure that the signal incident in that direction passes through the spatial filter without distortion, we should have:

[0013] y0(n)=w H x0(n)=w H a(θ0)s0(n)=s0(n)

[0014] Therefore, the weight vector w should satisfy:

[0015] w H a(θ0)=1

[0016] Under the condition that the above equation holds, the weight vector w is chosen to minimize the average output power P(θ) of the spatial filter, that is, to suppress signals and noise in other directions as much as possible. This is a conditional extremum problem, which can be described as:

[0017]

[0018] Construct the cost function:

[0019] J(w)=w H Rw+λ(1-w H a(θ0))

[0020] Taking the gradient of w and setting it to zero, we get:

[0021]

[0022] Right now:

[0023] Rw=λa(θ0)

[0024] w=λR -1 a(θ0)

[0025] The optimal weight vector for the MVDR beamformer can be obtained as follows:

[0026]

[0027] In practical engineering applications, the spatial correlation matrix R of the array is estimated using the observation data vectors obtained from a finite number of snapshots, by time averaging, i.e.:

[0028]

[0029] Where N is the number of snapshots of the array received signal vector.

[0030] Traditionally, the MVDR algorithm requires the design of an independent receiving and processing channel for each array element. For aircraft such as missiles, due to limitations in size, weight, and power consumption, it is difficult to implement an independent receiving and processing channel for each array element. Summary of the Invention

[0031] The purpose of this invention is to overcome the shortcomings of the prior art and provide an anti-interference receiving system and design method for a phased array antenna based on virtual subarrays. By dividing the planar phased array antenna into virtual subarrays and using subarray-level signal synthesis processing, the scale of frequency conversion and sampling circuits of independent receiving channels is greatly reduced. Combined with the MVDR algorithm, the interference direction signal is suppressed.

[0032] The objective of this invention is achieved through the following solution:

[0033] An anti-interference receiving system based on a virtual subarray phased array antenna, comprising a phased array antenna;

[0034] A phased array antenna consists of multiple subarrays. Each subarray is considered as an antenna, and each subarray generates a signal through analog synthesis.

[0035] The analog synthesized signal of each subarray is converted into a digital signal after passing through the frequency conversion module and the sampling module. Multiple subarray signals are used to achieve adaptive beamforming through digital beamforming and MVDR algorithm to suppress interference signals.

[0036] Furthermore, each subarray generates one signal through analog synthesis.

[0037] Furthermore, the phased array antenna includes a rectangular planar phased array antenna.

[0038] Furthermore, the phased array antenna includes multiple subarrays. Considering each subarray as an antenna, the specific steps include: constructing a two-dimensional virtual subarray located at the center of the rectangular planar phased array antenna using a two-dimensional subarray structure. The coordinates of each subarray center relative to the virtual subarray center O are (x(k), y(k)), where k is the subarray number; the desired signal azimuth angle is... Calculate the virtual subarray steering vector based on the virtual subarray array arrangement. Simulated synthesis weight vector * indicates conjugate; steering vector between submatrices:

[0039] N is the number of subarrays.

[0040]

[0041] Furthermore, the signals within each subarray are first synthesized through analog synthesis, with the analog synthesis weight vector being ω and the subarray output signal being x(n).

[0042] Based on the principle of the MVDR algorithm, the optimized steering vector value between subarrays is calculated using the following formula:

[0043]

[0044] T H Let T' denote the conjugate transpose of T, and T' denote the transpose of T. R is estimated by time averaging the subarray output signal x(n) obtained using a finite number of snapshots, i.e.:

[0045]

[0046] N is the number of snapshots of the array received signal vector.

[0047] Furthermore, based on the calculated optimized value T of the inter-subarray steering vector... opt The final output signal y(n) = T of the rectangular planar phased array antenna is calculated. H opt x′(n).

[0048] Furthermore, N is not less than 1024.

[0049] A design method for an anti-interference receiving system based on a virtual subarray phased array antenna includes the following steps:

[0050] S1, construct a two-dimensional virtual subarray;

[0051] S2, each two-dimensional virtual subarray coverage area is constructed into a subarray, and each subarray forms an analog signal through analog synthesis. Each analog signal is digitized through independent frequency conversion and sampling circuits to obtain the received data x(n) of each subarray.

[0052] S3, consisting of a virtual subarray arrangement and the desired signal azimuth angle. Calculate the virtual subarray steering vector Simulated synthesis weight vector * indicates conjugation, where all submatrices use the same simulated composite weight vector ω;

[0053] S4, based on the spatial positional relationship between the center position of each subarray and the center position of the two-dimensional virtual subarray, and the desired signal azimuth angle... Establish the transformation matrix Using the transformation matrix And the MVDR algorithm is used to calculate the optimal transformation matrix T for the received data x(n) from each subarray. opt ;

[0054] S5, using T opt The received data x(n) from each subarray are weighted to obtain the final output data of the rectangular planar phased array antenna.

[0055] Further, in step S1, constructing the two-dimensional virtual subarray includes the sub-step of constructing a two-dimensional virtual subarray located at the center of a rectangular planar phased array antenna.

[0056] Furthermore, in step S1, it is ensured that the rectangular planar phased array antenna is seamlessly covered by a combination of multiple two-dimensional virtual subarrays.

[0057] The beneficial effects of this invention include:

[0058] This invention can reduce the number of receiving channels, reduce the complexity of the receiving system, and facilitate engineering implementation while retaining the anti-interference capability of the receiving system.

[0059] This invention reduces the number of independent receiving channel frequency conversion and sampling circuits to 1 / M (where M is the number of subarray elements) through subarray-level synthesis, while maintaining the same anti-interference performance. Due to the significant reduction in the number of independent receiving channel frequency conversion and sampling circuits, the hardware circuit complexity is reduced, and the device size, weight, and power consumption are decreased, which is beneficial for engineering applications on miniaturized aircraft platforms such as missiles. Attached Figure Description

[0060] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the 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.

[0061] Figure 1 This is a schematic diagram illustrating the principle of digital beamforming technology in the MVDR algorithm.

[0062] Figure 2 This is a schematic diagram illustrating the principle of digital beamforming technology in the subarray-level MVDR algorithm according to an embodiment of the present invention.

[0063] Figure 3 This is a schematic diagram of the subarray and virtual subarray layout according to an embodiment of the present invention. Detailed Implementation

[0064] All features disclosed in all embodiments of this specification, or steps in all methods or processes implied in the disclosure, may be combined and / or extended or replaced in any way, except for mutually exclusive features and / or steps.

[0065] Given the problems mentioned in the background, the MVDR algorithm has a large number of independent receiving and processing channels, making it difficult to implement in space-constrained aircraft such as missiles. One embodiment of the present invention provides a design method that can reduce the number of receiving channels and lower the complexity of the receiving system, while preserving the anti-interference capability of the receiving system and facilitating engineering implementation.

[0066] This embodiment divides the planar phased array antenna into virtual subarrays and uses subarray-level signal synthesis processing, which greatly reduces the scale of independent receiving channel frequency conversion and sampling circuits, and combines the MVDR algorithm to suppress interference direction signals.

[0067] like Figure 2 and Figure 3 As shown. According to the present invention, a two-dimensional virtual subarray is constructed at the center of a rectangular planar phased array antenna to ensure seamless coverage of the rectangular planar phased array antenna by multiple two-dimensional virtual subarrays; the coverage area of ​​each two-dimensional virtual subarray is constructed into a subarray, and a signal is formed within each subarray through analog synthesis; the arrangement of the virtual subarray array and the desired signal azimuth angle are determined by the arrangement of the virtual subarray array and the desired signal azimuth angle. Calculate the virtual subarray steering vector Simulated synthesis weight vector (* indicates conjugate), all subarrays use the same simulated composite weight vector ω; based on the spatial positional relationship between the center position of each subarray and the center position of the two-dimensional virtual subarray, and the desired signal azimuth angle. Establish the transformation matrix Using the transformation matrix And the MVDR algorithm is used to calculate the optimal transformation matrix T for the received data x(n) from each subarray. opt Using T opt The received data x(n) from each subarray are weighted to obtain the final output data of the rectangular planar phased array antenna.

[0068] It should be noted that, within the scope of protection defined in the claims of this invention, the following embodiments can be combined and / or extended or replaced in any logical manner from the above specific embodiments, such as the disclosed technical principles, disclosed technical features or implicitly disclosed technical features.

[0069] Example 1

[0070] An anti-interference receiving system based on a virtual subarray phased array antenna, comprising a phased array antenna;

[0071] A phased array antenna consists of multiple subarrays. Each subarray is considered as an antenna, and each subarray generates a signal through analog synthesis.

[0072] The analog synthesized signal of each subarray is converted into a digital signal after passing through the frequency conversion module and the sampling module. Multiple subarray signals are used to achieve adaptive beamforming through digital beamforming and MVDR algorithm to suppress interference signals.

[0073] Example 2

[0074] Based on Example 1, each subarray generates one signal through analog synthesis.

[0075] Example 3

[0076] Based on Embodiment 1, the phased array antenna includes a rectangular planar phased array antenna.

[0077] Example 4

[0078] Based on Embodiment 1, the phased array antenna includes multiple subarrays. Considering each subarray as an antenna, the specific steps include: constructing a two-dimensional virtual subarray located at the center of the rectangular planar phased array antenna using a two-dimensional subarray structure. The coordinates of each subarray center relative to the virtual subarray center O are (x(k), y(k)), where k is the subarray number; the desired signal azimuth angle is... Calculate the virtual subarray steering vector based on the virtual subarray array arrangement. Simulated synthesis weight vector * indicates conjugate; steering vector between submatrices:

[0079] N is the number of subarrays.

[0080]

[0081] Example 5

[0082] Based on Example 1, the signal synthesis within each subarray is first completed by analog synthesis. The analog synthesis weight vector is ω, and the subarray output signal is x(n).

[0083] Based on the principle of the MVDR algorithm, the optimized steering vector value between subarrays is calculated using the following formula:

[0084]

[0085] T H Let T' denote the conjugate transpose of T, and T' denote the transpose of T. R is estimated by time averaging the subarray output signal x(n) obtained using a finite number of snapshots, i.e.:

[0086]

[0087] N is the number of snapshots of the array received signal vector.

[0088] Example 6

[0089] Based on Example 1, the calculated optimized value T of the inter-subarray steering vector is used. opt The final output signal y(n) = T of the rectangular planar phased array antenna is calculated. H opt x′(n).

[0090] Example 7

[0091] Based on Example 5, N is not less than 1024.

[0092] Example 8

[0093] A design method for an anti-interference receiving system based on a virtual subarray phased array antenna includes the following steps:

[0094] S1, construct a two-dimensional virtual subarray;

[0095] S2, each two-dimensional virtual subarray coverage area is constructed into a subarray, and each subarray forms an analog signal through analog synthesis. Each analog signal is digitized through independent frequency conversion and sampling circuits to obtain the received data x(n) of each subarray.

[0096] S3, consisting of a virtual subarray arrangement and the desired signal azimuth angle. Calculate the virtual subarray steering vector Simulated synthesis weight vector * indicates conjugation, where all submatrices use the same simulated composite weight vector ω;

[0097] S4, based on the spatial positional relationship between the center position of each subarray and the center position of the two-dimensional virtual subarray, and the desired signal azimuth angle... Establish the transformation matrix Using the transformation matrix And the MVDR algorithm is used to calculate the optimal transformation matrix T for the received data x(n) from each subarray. opt ;

[0098] S5, using T opt The received data x(n) from each subarray are weighted to obtain the final output data of the rectangular planar phased array antenna.

[0099] Example 9

[0100] Based on Example 8, in step S1, the construction of the two-dimensional virtual subarray includes the sub-step of constructing a two-dimensional virtual subarray located at the center of a rectangular planar phased array antenna.

[0101] Example 10

[0102] Based on Example 9, in step S1, it is ensured that the rectangular planar phased array antenna is seamlessly covered by a combination of multiple two-dimensional virtual subarrays.

[0103] The units described in the embodiments of the present invention can be implemented in software or hardware, and the described units can also be located in a processor. The names of these units do not necessarily limit the specific unit itself.

[0104] According to one aspect of the present invention, a computer program product or computer program is provided, the computer program product or computer program including computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium, and executes the computer instructions, causing the computer device to perform the methods provided in the various optional implementations described above.

[0105] In another aspect, embodiments of the present invention also provide a computer-readable medium, which may be included in the electronic device described in the above embodiments; or it may exist independently and not assembled into the electronic device. The computer-readable medium carries one or more programs, which, when executed by the electronic device, cause the electronic device to perform the methods described in the above embodiments.

[0106] All parts not covered in this invention are the same as or can be implemented using existing technologies.

[0107] The above technical solution is only one embodiment of the present invention. For those skilled in the art, based on the application methods and principles disclosed in the present invention, it is easy to make various types of improvements or modifications, and not limited to the methods described in the above specific embodiments of the present invention. Therefore, the methods described above are only preferred and are not restrictive.

[0108] In addition to the examples above, other embodiments may be obtained by those skilled in the art based on the above disclosure or by making modifications using knowledge or technology in related fields. The features of each embodiment may be interchanged or replaced. Modifications and changes made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A phased array antenna anti-interference receiving system based on a virtual subarray, characterized in that, Including phased array antennas; The phased array antenna comprises multiple subarrays, each considered as an antenna. Each subarray generates a signal through analog synthesis. Specifically, the phased array antenna includes: constructing a two-dimensional virtual subarray located at the center of a rectangular planar phased array antenna using a two-dimensional subarray structure. The coordinates of each subarray center relative to the virtual subarray center O are (x(k), y(k)), where k is the subarray number; the desired signal azimuth angle is... Calculate the virtual subarray steering vector based on the virtual subarray array arrangement. Simulated synthesis of weight vectors , Indicates conjugate; guiding vector between submatrices: ； The analog synthesized signal of each subarray is converted into a digital signal after passing through the frequency conversion module and the sampling module. Multiple subarray signals are used to achieve adaptive beamforming through digital beamforming and MVDR algorithm to suppress interference signals.

2. The phased array antenna anti-interference receiving system based on virtual subarray according to claim 1, characterized in that, Each subarray generates one signal through analog synthesis.

3. The phased array antenna anti-interference receiving system based on virtual subarray according to claim 1, characterized in that, The phased array antenna includes a rectangular planar phased array antenna.

4. The phased array antenna anti-interference receiving system based on virtual subarray according to claim 1, characterized in that, First, the signal synthesis within each subarray is completed using analog synthesis. Based on the principle of the MVDR algorithm, the optimized steering vector value between subarrays is calculated using the following formula: Indicates taking The conjugate transpose of . Indicates taking transpose, Subarray output signal obtained using a finite number of snapshots The estimate is obtained by using time averaging, i.e.: It is the number of snapshots of the array received signal vector.

5. The phased array antenna anti-interference receiving system based on virtual subarray according to claim 1, characterized in that, Based on the calculated optimized value of the inter-subarray steering vector The final output signal of the rectangular planar phased array antenna was calculated. .

6. The phased array antenna anti-interference receiving system based on virtual subarray according to claim 4, characterized in that, Not less than 1024.

7. A design method for an anti-interference receiving system based on a phased array antenna with a virtual subarray, characterized in that, The phased array antenna anti-interference receiving system based on virtual subarray as described in claim 1 includes the following steps: S1, construct a two-dimensional virtual subarray; S2, each two-dimensional virtual subarray coverage area is constructed into a subarray. Within each subarray, an analog signal is formed through analog synthesis. Each analog signal is digitized through independent frequency conversion and sampling circuits to obtain the output signal of each subarray. ; S3, consisting of a virtual subarray arrangement and the desired signal azimuth angle. Calculate the virtual subarray steering vector Simulated synthesis of weight vectors , This indicates that conjugate weights are used for all submatrices, and the same simulated composite weight vector is used for all submatrices. ; S4, based on the spatial positional relationship between the center position of each subarray and the center position of the two-dimensional virtual subarray, and the desired signal azimuth angle... Establish the transformation matrix Using the transformation matrix and the output signals of each subarray Run the MVDR algorithm to calculate the optimal transformation matrix. ; S5, utilizing Output signals for each subarray Weighted summaries are applied to obtain the final output data of the rectangular planar phased array antenna.

8. The design method of the phased array antenna anti-interference receiving system based on virtual subarray according to claim 7, characterized in that, In step S1, constructing the two-dimensional virtual subarray includes the sub-step of constructing a two-dimensional virtual subarray located at the center of a rectangular planar phased array antenna.

9. The design method of the phased array antenna anti-interference receiving system based on virtual subarray according to claim 8, characterized in that, In step S1, it is ensured that the rectangular planar phased array antenna is seamlessly covered by a combination of multiple two-dimensional virtual subarrays.

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