Space-time-polarization domain beam null broadening method for planar vector array antenna

Abstract

The application provides a space-time-polarization domain beam null broadening method for a planar vector array antenna, relates to the field of array signal processing and comprises the following steps: calculating a sample covariance matrix based on a space-time-polarization domain joint anti-interference structure of the planar vector array antenna; dividing a plurality of space-time-polarization domain five-dimensional joint basic sub-band units and calculating space-time-polarization domain joint spectrum estimation values; setting a beam null broadening area based on the direction of a real interference signal and broadening requirements, resetting the space-time-polarization joint spectrum estimation values in the beam null broadening area, reconstructing a space-time-polarization domain interference covariance matrix; performing characteristic decomposition on the sample covariance matrix and reconstructing a noise covariance matrix; reconstructing a space-time-polarization domain joint interference plus noise covariance matrix and solving planar vector array antenna weight vectors. The application realizes beam null broadening in the space-time-polarization domain of the planar vector array antenna and suppresses interference under the disturbance condition of the direction of an interference signal.

Description

Technical Field

[0001] This invention relates to the field of array signal processing, and in particular to a method for space-time-polarization domain beam nulling broadening for planar vector array antennas. Background Technology

[0002] Global Navigation Satellite Systems (GNSS) are widely used because they provide users with all-weather, high-precision positioning, velocity measurement, and timing services. However, the signal power of navigation satellites reaching the receiver is extremely weak, sometimes even 20 dB lower than the receiver's thermal noise. Therefore, satellite navigation receivers are highly susceptible to suppression by strong interference signals, posing a significant threat to the application of satellite navigation systems. To address this, satellite navigation receivers are often equipped with array antennas that adaptively create beam nulls in the direction of strong interference signals, thereby suppressing interference.

[0003] Array antennas are divided into scalar array antennas and vector array antennas. Compared with scalar array antennas, vector array antennas can also be sensitive to the polarization domain information of the incident signal. The space-time-polarization domain joint anti-interference structure based on vector array antennas can suppress strong interference signals simultaneously in the spatial, temporal, and polarization domains, effectively improving the anti-interference degree of freedom of the array antenna without increasing the number of array elements.

[0004] When the suppressed interference signal is incident on the vector array antenna, the traditional space-time-polarization domain adaptive anti-interference algorithm will adaptively calculate the weights corresponding to each channel of the array antenna based on the currently acquired data, and then use these weights to match the next segment of data. The data of each channel is weighted and combined to achieve adaptive suppression of the suppressed interference signal.

[0005] When the receiver (including the array antenna) is stationary or moving at low speed, the narrow beam null remains effective because the direction of the suppressed interference signal in the data used to calculate the weights and the matching data does not change or changes only slightly. However, when the receiver moves at high speed, such as high-speed linear motion or high-speed rotation, the direction of the suppressed interference signal incident on the array antenna changes rapidly. The direction of the suppressed interference signal in the previous segment of data used to calculate the weights differs significantly from the direction of the suppressed interference signal in the next segment of matching data. At this time, the adaptively generated beam null mismatches with the actual direction of the interference signal in the matching data, that is, the direction of the interference signal shifts out of the narrow beam null, causing a sharp decline in the output performance of the array antenna.

[0006] Widening beam nulls is an effective solution. Its core idea is to adaptively generate wide beam nulls by adding virtual interference sources to the vicinity of real interference signals.

[0007] For vector array antennas, a beam nulling method based on a joint space-time-polarization domain anti-interference structure has been proposed. However, this method, based on the classical covariance matrix taper method, requires solving for the taper matrix and is only applicable to linear arrays. The joint space-time-polarization domain anti-interference structure of planar vector array antennas is complex, especially since polarization domain information is coupled with spatial domain information. Therefore, it is impossible to derive an analytical solution for the taper matrix using the classical covariance matrix taper method. Consequently, extending the aforementioned covariance matrix taper (CMT) algorithm to the joint space-time-polarization domain presents difficulties, making it impossible to achieve beam nulling and interference suppression in the joint space-time-polarization domain anti-interference structure of planar vector array antennas using the classical covariance matrix taper method. Summary of the Invention

[0008] The purpose of this invention is to provide a method for beam nulling in the space-time-polarization domain for planar vector array antennas, in order to solve the problem that traditional algorithms cannot achieve beam nulling in the space-time-polarization domain joint anti-interference structure of planar vector array antennas under high-speed carrier motion environments.

[0009] To achieve the above objectives, the present invention provides the following solution:

[0010] A method for space-time-polarization domain beam nulling for planar vector array antennas includes:

[0011] Based on the joint anti-interference structure of the space-time-polarization domain of the planar vector array antenna, the sampling covariance matrix is ​​calculated;

[0012] The space-time-polarization domain is divided into several five-dimensional joint basic sub-band units of the space-time-polarization domain; the five-dimensional joint basic sub-band units of the space-time-polarization domain include pitch angle, azimuth angle, frequency, polarization phase difference and polarization amplitude ratio information;

[0013] Based on the five-dimensional joint basic sub-band unit of the space-time-polarization domain, the space-time-polarization joint spectrum estimate of the five-dimensional joint basic sub-band unit of the space-time-polarization domain is calculated according to the sampling covariance matrix.

[0014] Based on the actual interference signal direction and beam widening requirements, a beam nulling widening region is defined, and the space-time-polarization joint spectrum estimate of the five-dimensional joint basic sub-band unit in the space-time-polarization domain within the beam nulling widening region is reset to reconstruct the space-time-polarization domain interference covariance matrix. The beam nulling widening requirements include beam nulling widening requirements in the elevation direction and beam nulling widening requirements in the azimuth direction.

[0015] The sampling covariance matrix is ​​subjected to eigenvalue decomposition to reconstruct the noise covariance matrix;

[0016] Reconstruct the joint interference plus noise covariance matrix in the space-time-polarization domain based on the space-time-polarization domain interference covariance matrix and the noise covariance matrix;

[0017] The weight vector of the planar vector array antenna is solved based on the covariance matrix of the joint interference plus noise in the space-time-polarization domain; the weight vector of the planar vector antenna is used to match the input data of the planar vector array antenna in order to broaden the beam null width.

[0018] Optionally, based on the five-dimensional joint fundamental sub-band unit of the space-time-polarization domain, the space-time-polarization joint spectrum estimate of the five-dimensional joint fundamental sub-band unit of the space-time-polarization domain is calculated according to the sampling covariance matrix, specifically including:

[0019] Based on the five-dimensional joint basic sub-band unit of the space-time-polarization domain, calculate the joint steering vector of the space-time-polarization domain;

[0020] The estimated spatiotemporal-polarimetric spectrum of the five-dimensional joint basic subband unit in the spatiotemporal-polarimetric domain is calculated based on the sampling covariance matrix and the spatiotemporal-polarimetric joint steering vector.

[0021] Optionally, based on the actual interference signal direction and broadening requirements, a beam null broadening region is defined, and the estimated values ​​of the spatiotemporal-polarization joint spectrum of the five-dimensional joint basic sub-band units in the spatiotemporal-polarization domain within the beam null broadening region are reset. The spatiotemporal-polarization domain interference covariance matrix is ​​then reconstructed, specifically including:

[0022] The beam nulling area corresponding to any interference signal is determined based on the beam nulling requirements in the elevation and azimuth directions.

[0023] The estimated value of the joint space-time polarization spectrum in the beam null broadening region is determined based on the estimated value of the joint space-time polarization spectrum of the five-dimensional joint basic sub-band unit in the space-time polarization domain.

[0024] The maximum value of the space-time-polarization joint spectrum estimate corresponding to each frequency sub-band within the beam null broadening region is selected;

[0025] The space-time-polarization joint spectrum estimate within the beam nulling region is reset to the maximum value corresponding to each frequency sub-band, and the space-time-polarization domain interference covariance matrix is ​​reconstructed.

[0026] Optionally, based on the joint anti-interference structure of the space-time-polarization domain of the planar vector array antenna, the sampling covariance matrix is ​​calculated, specifically including:

[0027] Based on the space-time-polarization domain joint anti-interference structure of the planar vector array antenna, using the formula Calculate the sampling covariance matrix;

[0028] in, Let X be the sampling covariance matrix; n This represents the nth data block signal received by the space-time-polarization domain joint anti-interference structure based on a planar vector array antenna; N is the total number of data blocks. It is the conjugate transpose of the nth data block signal.

[0029] Optionally, based on the five-dimensional joint basic sub-band unit of the space-time-polarization domain, the joint steering vector of the space-time-polarization domain is calculated, specifically including:

[0030] Based on the five-dimensional joint basic subband unit of the space-time-polarization domain, according to the formula Calculate the joint steering vector in the space-time-polarization domain;

[0031] in, θ is the joint steering vector of the space-time-polarization domain. u Let φ be the u-th pitch angle. v Let f be the v-th azimuth angle. b For the b-th frequency, γ i For the i-th polarization amplitude ratio, η j Let j be the polarization phase difference; For time-domain steering vectors, It is a spatial guiding vector. It is the polarization domain steering vector.

[0032] Optionally, the space-time-polarization joint spectrum estimate of the five-dimensional joint basic subband unit in the space-time-polarization domain is calculated based on the sampling covariance matrix and the space-time-polarization joint steering vector, specifically including:

[0033] According to the formula Calculate the space-time-polarization joint spectrum estimate of the five-dimensional joint basic subband unit in the space-time-polarization domain;

[0034] in, Let θ be the estimate of the space-time polarization joint spectrum of the five-dimensional joint basic subband unit in the space-time polarization domain. u Let φ be the u-th pitch angle. v Let f be the v-th azimuth angle. b For the b-th frequency, γ i For the i-th polarization amplitude ratio, η j Let j be the polarization phase difference; It is the conjugate transpose of the joint steering vector of the space-time-polarization domain; is the inverse of the sampling covariance matrix.

[0035] Optionally, the space-time-polarization joint spectrum estimate within the beam nulling region is reset to the maximum value corresponding to each frequency sub-band, and the space-time-polarization domain interference covariance matrix is ​​reconstructed, specifically including:

[0036] Using formula Reconstructing the space-time-polarization domain disturbance covariance matrix;

[0037] in, The space-time-polarization domain interference covariance matrix; This represents the beam null broadening region corresponding to the Jth interference signal; The space-time-polarization joint spectrum estimate after resetting within the beam null broadening region, where θ is the elevation angle, φ is the azimuth angle, f is the frequency, and the parameter (ζ) is... l ,υ l ) represents the polarization domain parameter of the l-th interference signal, where ζ l Indicates the polarization amplitude ratio, υ l Indicates polarization phase difference; The space-time-polarization joint steering vector for each five-dimensional joint basic sub-band unit of the space-time-polarization domain within the beam nulling region; GF is the conjugate transpose of the space-time-polarization joint steering vector; L is the total number of interfering signals; GF is the number of frequency sub-bands within the beam null widening region; GP is the number of elevation angle cells within the beam null widening region; GA is the number of azimuth angle cells within the beam null widening region. Let α be the estimated value of the joint space-time polarization spectrum after resetting any five-dimensional joint basic subband unit of the space-time polarization domain within the beam null broadening region. l,i Let β be the elevation angle of any five-dimensional joint basic subband unit in the space-time-polarization domain within the beam nulling region. l,j f represents the azimuth angle of any five-dimensional joint basic sub-band unit in the space-time-polarization domain within the beam nulling region. r,l Let f be the starting frequency of the l-th interference signal, ξ be the frequency sub-band, and f be the frequency frequency. bin The frequency width of the division; The space-time-polarization joint steering vector for any five-dimensional joint basic sub-band unit of the space-time-polarization domain within the beam nulling region; θ is the conjugate transpose of the spacetime-polarization joint steering vector; bin φ is the width of the pitch angle division. bin f is the azimuth width of the division. bin The frequency width of the division; This represents the maximum value of the space-time-polarization joint spectrum estimate corresponding to each frequency within the beam null broadening region; The spatial steering vector for any five-dimensional joint basic sub-band unit of the space-time-polarization domain within the beam nulling region; For Kronecker product; The polarization domain steering vector for any five-dimensional joint basic sub-band unit of the space-time-polarization domain within the beam nulling region; H is the time-domain steering vector of any five-dimensional joint basic subband unit of the space-time-polarization domain within the beam nulling region; H is the conjugate transpose.

[0038] Optionally, the sampling covariance matrix is ​​subjected to eigenvalue decomposition to reconstruct the noise covariance matrix, specifically including:

[0039] The sampling covariance matrix is ​​subjected to eigenvalue decomposition, and the minimum eigenvalue is used as the noise signal power estimate. The formula is then applied. Reconstruct the noise covariance matrix;

[0040] in, Here is the noise covariance matrix; λ is the estimated power of the noise signal. 2MK I is the smallest eigenvalue of the sampling covariance matrix; 2MK It is a 2MK-dimensional identity matrix.

[0041] Optionally, the joint interference-noise covariance matrix in the space-time-polarization domain is reconstructed based on the space-time-polarization domain interference covariance matrix and the noise covariance matrix, specifically including:

[0042] According to the formula Reconstruct the joint interference and noise covariance matrix in the space-time-polarization domain;

[0043] in, The covariance matrix of joint interference and noise in the space-time-polarization domain; The space-time-polarization domain interference covariance matrix; This represents the beam null broadening region corresponding to the Jth interference signal; The estimated value of the space-time-polarization joint spectrum after resetting within the beam nulling broadening region; The space-time-polarization joint steering vector for each basic sub-band unit within the beam nulling region; It is the conjugate transpose of the space-time-polarization joint steering vector.

[0044] Optionally, the weight vectors of all planar vector array antennas are solved based on the joint interference-noise covariance matrix in the space-time-polarization domain, specifically including:

[0045] According to the formula Solve for the weight vectors of all planar vector array antennas; where W is the weight vector; C is the constraint condition; C H is the conjugate transpose of the constraint; Q is the constraint value.

[0046] According to specific embodiments provided by the present invention, the following technical effects are disclosed: The present invention avoids the difficulty of solving the cone matrix required by the CMT algorithm. Firstly, the spatial domain, temporal domain, and polarization domain are each divided into several five-dimensional joint basic sub-band units of the spatial-temporal-polarization domain. The interference signal parameters are estimated by utilizing the characteristic that the power of the interference signal is much greater than the power of the desired GNSS signal and noise. Based directly on several five-dimensional joint basic sub-band units of the spatial-temporal-polarization domain near the interference signal, and based on the actual interference signal's directional distance range, according to the spatial-temporal-polarization domain... Based on the spatial-temporal-polarimetric joint spectrum estimation of the five-dimensional joint basic sub-band unit in the spatial domain and the beam nulling requirement, the spatial-temporal-polarimetric interference covariance matrix is ​​reconstructed, and the sampling covariance matrix is ​​eigenvalued to reconstruct the noise covariance matrix. The spatial-temporal-polarimetric joint interference plus noise covariance matrix is ​​then reconstructed based on the interference and noise covariance matrices. Finally, the weight vectors of all planar vector array antennas are calculated based on the spatial-temporal-polarimetric joint interference plus noise covariance matrix to adjust the beam null width. This ultimately achieves beam nulling in the interference spatial domain, enabling it to cope with rapidly changing real interference signals. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments 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.

[0048] Figure 1 Flowchart of the space-time-polarization domain beam nulling method for planar vector array antennas provided by the present invention;

[0049] Figure 2 A schematic diagram of the space-time-polarization domain joint anti-interference structure of the planar vector array antenna provided by the present invention;

[0050] Figure 3 A schematic diagram of the five-dimensional joint basic sub-band unit division of the space-time-polarization domain;

[0051] Figure 4 Schematic diagram of the beam null widening region;

[0052] Figure 5 This is a schematic diagram illustrating the beam nulling effect provided by the present invention; wherein, Figure 5 (a) in the diagram is a schematic of the beam null before beam broadening; Figure 5 (b) in the diagram is a schematic diagram of the beam null after widening. Detailed Implementation

[0053] like Figure 1 As shown, this invention provides a method for space-time-polarization domain beam nulling broadening of planar vector array antennas, including:

[0054] Step 101: Calculate the sampling covariance matrix based on the joint anti-interference structure of the space-time-polarization domain of the planar vector array antenna.

[0055] Planar vector array antenna space-time-polarization domain joint anti-interference structure, such as Figure 2 As shown, in practical applications, step 101 specifically includes: based on the space-time-polarization domain joint anti-interference structure of the planar vector array antenna, using the formula... Calculate the sampling covariance matrix; where, Let X be the sampling covariance matrix; n This refers to the nth data block signal received by the space-time-polarization domain joint anti-interference structure based on a planar vector array antenna.

[0056] This represents the data corresponding to the k-th tap after the horizontal electric dipole of the m-th element. This represents the data corresponding to the k-tap after the vertical electric dipole of the m-th array element; N is the total number of data blocks. It is the conjugate transpose of the nth data block signal.

[0057] Step 102: Divide the space-time-polarization domain into several five-dimensional joint basic sub-band units; the five-dimensional joint basic sub-band units include elevation angle, azimuth angle, frequency domain, polarization phase difference, and polarization amplitude ratio, such as... Figure 3 As shown.

[0058] In practical applications, the space-time-polarization joint domain Λ STP The space-time-polarization domain is uniformly divided into five-dimensional joint basic sub-band units (θ) of U×V×B×I×J. u ,φ v ,f b ,γ i ,η j ).

[0059] ①The space-time-polarization joint domain is Λ STP ={(θ,φ,f,γ,η)|θ∈[0,π / 2],φ∈[0,2π),f∈(0,f L ],γ∈[0,π / 2],η∈[0,2π)}.

[0060] ② Set the pitch angle parameter set Θ P ={θ|θ∈[0,π / 2]}, azimuth parameter set ΘA ={φ|φ∈[0,2π)}, frequency domain parameter set Ω, polarization amplitude ratio parameter set Φ P ={γ|γ∈[0,π / 2]} and the polarization phase difference parameter set Φ A ={η|η∈[0,2π)} are uniformly divided into U, V, B, I, and J parts, respectively, thus generating U×V×B×I×J parts of the space-time-polarization domain five-dimensional joint basic sub-band unit (θ). u ,φ v ,f b ,γ i ,η j ).

[0061] Step 103: Based on the five-dimensional joint basic sub-band unit of the space-time-polarization domain, calculate the space-time-polarization joint spectrum estimate of the five-dimensional joint basic sub-band unit of the space-time-polarization domain according to the sampling covariance matrix.

[0062] In practical applications, step 103 specifically includes: calculating the joint steering vector of the space-time-polarization domain based on the five-dimensional joint basic sub-band unit of the space-time-polarization domain; and calculating the space-time-polarization joint spectrum estimate of the five-dimensional joint basic sub-band unit of the space-time-polarization domain based on the sampling covariance matrix and the joint steering vector of the space-time-polarization domain.

[0063] Specifically, the calculation of the joint steering vector of the space-time-polarization domain based on the five-dimensional joint basic sub-band unit of the space-time-polarization domain includes: based on the five-dimensional joint basic sub-band unit of the space-time-polarization domain, according to the formula... Calculate the joint steering vector in the space-time-polarization domain; where, θ is the joint steering vector of the space-time-polarization domain. u Let φ be the u-th pitch angle. v Let f be the v-th azimuth angle. b For the b-th frequency domain, γ i For the i-th polarization amplitude ratio, η j Let j be the polarization phase difference; For time-domain steering vectors, It is a spatial guiding vector. It is the polarization domain steering vector.

[0064] The spatial-temporal-polarization joint spectrum estimate of the five-dimensional joint basic subband unit in the spatial-temporal-polarization domain is calculated based on the sampling covariance matrix and the joint steering vector of the spatial-temporal-polarization domain. Specifically, this includes: calculating the spatial-temporal-polarization joint spectrum estimate of the five-dimensional joint basic subband unit in the spatial-temporal-polarization domain according to the formula. Calculate the space-time-polarization joint spectrum estimate of the five-dimensional joint basic subband unit in the space-time-polarization domain; where, Let θ be the estimate of the space-time polarization joint spectrum of the five-dimensional joint basic subband unit in the space-time polarization domain.u Let φ be the u-th pitch angle. v Let f be the v-th azimuth angle. b For the b-th frequency domain, γ i For the i-th polarization amplitude ratio, η j Let j be the polarization phase difference; It is the conjugate transpose of the joint steering vector of the space-time-polarization domain; is the inverse of the sampling covariance matrix.

[0065] Step 104: Based on the actual direction of interference signal, set the beam nulling broadening requirement, and reconstruct the space-time-polarization domain interference covariance matrix from the estimated values ​​of the space-time-polarization joint spectrum of the five-dimensional joint basic sub-band units in the space-time-polarization domain within the beam nulling broadening region; the beam nulling broadening requirement includes beam nulling broadening requirements in the elevation direction and beam nulling broadening requirements in the azimuth direction, such as... Figure 4 As shown.

[0066] In practical applications, the beam nulling requirement in the pitch direction is set as (G P +1)θ bin The beam nulling requirement in the azimuth direction is (G A +1)θ bin The beam null broadening region corresponding to the l-th interference signal can be determined.

[0067] Specifically as follows:

[0068] The l-th beam null broadening region ( The space-time-polarization joint spectrum estimation matrix (a three-dimensional matrix with variables being pitch angle, azimuth angle, and frequency) corresponds to this matrix. (ξ represents the ξ-th frequency sub-band. Since the matrix is ​​three-dimensional, the variable frequencies must be fixed to represent it.) This can be written as:

[0069]

[0070] Find the maximum value of the space-time-polarization joint spectrum estimate for each frequency sub-band within the l-th beam null broadening region. The joint spectral estimate of the space-time-polarization domain within this frequency subband is reset to its maximum value. (This step is crucial for beam null widening. Based on the idea of ​​widening beam nulls through virtual interference, it achieves virtual interference by directly resetting the real interference signal to estimate the nearby space-time-polarization joint spectrum, thereby widening the beam null. This avoids the problem of solving the space-time-polarization joint tapering matrix when the traditional covariance matrix tapering method is applied to planar vector array antennas.)

[0071] Specifically as follows:

[0072]

[0073]

[0074] In practical applications, step 104 specifically includes: determining the beam nulling widening region corresponding to any interference signal based on the beam nulling widening requirements in the elevation and azimuth directions; determining the space-time-polarization joint spectrum estimate within the beam nulling widening region based on the space-time-polarization joint spectrum estimate of the five-dimensional joint basic sub-band unit in the space-time-polarization domain; selecting the maximum value of the space-time-polarization joint spectrum estimate corresponding to each frequency sub-band in the beam nulling widening region; resetting the maximum value to the space-time-polarization joint spectrum estimate within the actual interference signal's direction range, and reconstructing the space-time-polarization domain interference covariance matrix.

[0075] Specifically, reconstructing the space-time-polarization domain interference covariance matrix by resetting the maximum value to the estimated value of the space-time-polarization joint spectrum within the range of the actual interference signal includes:

[0076] Using formula

[0077] Reconstructing the space-time-polarization domain disturbance covariance matrix;

[0078] in, The space-time-polarization domain interference covariance matrix; This represents the beam null broadening region corresponding to the Jth interference signal; The space-time-polarization joint spectrum estimate after resetting within the beam null broadening region, where θ is the elevation angle, φ is the azimuth angle, f is the frequency, and the parameter (ζ) is... l ,υ l ) represents the polarization domain parameter of the l-th interference signal, where ζ l Indicates the polarization amplitude ratio, υ l Indicates polarization phase difference; The space-time-polarization joint steering vector for each five-dimensional joint basic sub-band unit of the space-time-polarization domain within the beam nulling region; GF is the conjugate transpose of the space-time-polarization joint steering vector; L is the total number of interfering signals; GF is the number of frequency sub-bands within the beam null widening region; GP is the number of elevation angle cells within the beam null widening region; GA is the number of azimuth angle cells within the beam null widening region. Let α be the estimated value of the joint space-time polarization spectrum after resetting any five-dimensional joint basic subband unit of the space-time polarization domain within the beam null broadening region. l,iLet β be the elevation angle of any five-dimensional joint basic subband unit in the space-time-polarization domain within the beam nulling region. l,j f represents the azimuth angle of any five-dimensional joint basic sub-band unit in the space-time-polarization domain within the beam nulling region. r,l Let f be the starting frequency of the l-th interference signal, ξ be the frequency sub-band, and f be the frequency frequency. bin The frequency width of the division; The space-time-polarization joint steering vector for any five-dimensional joint basic sub-band unit of the space-time-polarization domain within the beam nulling region; θ is the conjugate transpose of the spacetime-polarization joint steering vector; bin φ is the width of the pitch angle division. bin f is the azimuth width of the division. bin The frequency width of the division; This represents the maximum value of the space-time-polarization joint spectrum estimate corresponding to each frequency within the beam null broadening region; The spatial steering vector for any five-dimensional joint basic sub-band unit of the space-time-polarization domain within the beam nulling region; For Kronecker product; The polarization domain steering vector for any five-dimensional joint basic sub-band unit of the space-time-polarization domain within the beam nulling region; H is the time-domain steering vector of any five-dimensional joint basic sub-band unit of the space-time-polarization domain within the beam nulling region; H is the conjugate transpose.

[0079] Step 105: Perform eigenvalue decomposition on the sampling covariance matrix to reconstruct the noise covariance matrix.

[0080] In practical applications, noise power can be obtained by sampling the covariance matrix. The minimum eigenvalue is estimated, i.e.

[0081] Step 105 specifically includes: performing eigenvalue decomposition on the sampling covariance matrix, using the minimum eigenvalue as the noise signal power estimate, and applying the formula... Reconstruct the noise covariance matrix; where, Here is the noise covariance matrix; λ is the estimated power of the noise signal. 2MK I is the smallest eigenvalue of the sampling covariance matrix; 2MK It is a 2MK-dimensional identity matrix.

[0082] Step 106: Reconstruct the joint interference plus noise covariance matrix in the space-time-polarization domain based on the space-time-polarization domain interference covariance matrix and the noise covariance matrix.

[0083] In practical applications, step 106 specifically includes: according to the formula Reconstruct the joint interference and noise covariance matrix in the space-time-polarization domain; where... The covariance matrix of joint interference and noise in the space-time-polarization domain; The space-time-polarization domain interference covariance matrix; This represents the beam null broadening region corresponding to the Jth interference signal; The estimated value of the space-time-polarization joint spectrum after resetting within the beam nulling broadening region; The space-time-polarization joint steering vector for each basic sub-band unit within the beam nulling region; It is the conjugate transpose of the space-time-polarization joint steering vector.

[0084] Step 107: Solve for the weight vectors of all planar vector array antennas based on the joint interference-noise covariance matrix of the space-time-polarization domain; the weight vectors of the planar vector antennas are used to match the input data of the planar vector array antennas to adjust the beam null width, such as... Figure 5 As shown.

[0085] In practical applications, step 107 specifically includes: according to the formula Solve for the weight vectors of all planar vector array antennas; where W is the weight vector; C is the constraint condition; C H is the conjugate transpose of the constraint; Q is the constraint value.

[0086] Among them, constraint condition C and constraint value Q satisfy

[0087] This invention achieves beam nulling for planar vector array antennas through covariance matrix reconstruction in the space-time-polarization domain, solving the problem that the classical covariance matrix tapering method is not applicable to anti-interference structures in the space-time-polarization domain based on planar vector array antennas.

[0088] In the process of reconstructing the covariance matrix in the space-time-polarization domain, beam nulling can be achieved by resetting the joint spatial spectrum estimate in the space-time-polarization domain, and the beam nulling width can be precisely adjusted.

[0089] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0090] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for space-time-polarization domain beam nulling broadening of a planar vector array antenna, characterized in that, include: Based on the joint anti-interference structure of the space-time-polarization domain of the planar vector array antenna, the sampling covariance matrix is ​​calculated; The space-time-polarization domain is divided into several five-dimensional joint basic sub-band units of the space-time-polarization domain; the five-dimensional joint basic sub-band units of the space-time-polarization domain include pitch angle, azimuth angle, frequency, polarization phase difference and polarization amplitude ratio information; Based on the five-dimensional joint basic sub-band unit of the space-time-polarization domain, the space-time-polarization joint spectrum estimate of the five-dimensional joint basic sub-band unit of the space-time-polarization domain is calculated according to the sampling covariance matrix. Based on the actual interference signal direction and beam widening requirements, a beam nulling widening region is defined, and the space-time-polarization joint spectrum estimate of the five-dimensional joint basic sub-band unit in the space-time-polarization domain within the beam nulling widening region is reset to reconstruct the space-time-polarization domain interference covariance matrix. The beam nulling widening requirements include beam nulling widening requirements in the elevation direction and beam nulling widening requirements in the azimuth direction. The sampling covariance matrix is ​​subjected to eigenvalue decomposition to reconstruct the noise covariance matrix; Reconstruct the joint interference plus noise covariance matrix in the space-time-polarization domain based on the space-time-polarization domain interference covariance matrix and the noise covariance matrix; The weight vector of the planar vector array antenna is solved based on the covariance matrix of the joint interference plus noise in the space-time-polarization domain; the weight vector of the planar vector array antenna is used to match the input data of the planar vector array antenna in order to broaden the beam null width.

2. The method for space-time-polarization domain beam nulling broadening of a planar vector array antenna according to claim 1, characterized in that, Based on the five-dimensional joint fundamental sub-band unit of the space-time-polarization domain, the space-time-polarization joint spectrum estimate of the five-dimensional joint fundamental sub-band unit of the space-time-polarization domain is calculated according to the sampling covariance matrix, specifically including: Based on the five-dimensional joint basic sub-band unit of the space-time-polarization domain, calculate the joint steering vector of the space-time-polarization domain; The estimated spatiotemporal-polarimetric spectrum of the five-dimensional joint basic subband unit in the spatiotemporal-polarimetric domain is calculated based on the sampling covariance matrix and the spatiotemporal-polarimetric joint steering vector.

3. The method for space-time-polarization domain beam nulling broadening of a planar vector array antenna according to claim 1, characterized in that, Based on the actual direction of interference signals and broadening requirements, a beam null broadening region is defined. The estimated values ​​of the spatiotemporal-polarimetric joint spectrum of the five-dimensional joint basic sub-band units in the spatiotemporal-polarimetric domain within the beam null broadening region are reset, and the spatiotemporal-polarimetric domain interference covariance matrix is ​​reconstructed. Specifically, this includes: The beam nulling area corresponding to any interference signal is determined based on the beam nulling requirements in the elevation and azimuth directions. The estimated value of the joint space-time polarization spectrum in the beam null broadening region is determined based on the estimated value of the joint space-time polarization spectrum of the five-dimensional joint basic sub-band unit in the space-time polarization domain. The maximum value of the space-time-polarization joint spectrum estimate corresponding to each frequency sub-band within the beam null broadening region is selected; The space-time-polarization joint spectrum estimate within the beam nulling region is reset to the maximum value corresponding to each frequency sub-band, and the space-time-polarization domain interference covariance matrix is ​​reconstructed.

4. The method for space-time-polarization domain beam nulling broadening of a planar vector array antenna according to claim 1, characterized in that, Based on the joint anti-interference structure of the space-time-polarization domain of the planar vector array antenna, the sampling covariance matrix is ​​calculated, specifically including: Based on the space-time-polarization domain joint anti-interference structure of the planar vector array antenna, using the formula Calculate the sampling covariance matrix; in, Let be the sampling covariance matrix; The first received by the space-time-polarization domain joint anti-jamming structure based on a planar vector array antenna. One data block signal; N is the total number of data blocks; For the first The conjugate transpose of each data block signal.

5. The method for space-time-polarization domain beam nulling broadening of a planar vector array antenna according to claim 2, characterized in that, Based on the five-dimensional joint basic sub-band unit of the space-time-polarization domain, the joint steering vector of the space-time-polarization domain is calculated, specifically including: Based on the five-dimensional joint basic subband unit of the space-time-polarization domain, according to the formula Calculate the joint steering vector in the space-time-polarization domain; in, It is the joint steering vector of the space-time-polarization domain. Let u be the pitch angle. Let v be the azimuth angle. For the b-th frequency, For the i-th polarization amplitude ratio, Let j be the polarization phase difference; For time-domain steering vectors, It is a spatial guiding vector. It is the polarization domain steering vector.

6. The method for space-time-polarization domain beam nulling broadening of a planar vector array antenna according to claim 3, characterized in that, The spatial-temporal-polarization joint spectrum estimate of the five-dimensional joint basic subband unit in the spatial-temporal-polarization domain is calculated based on the sampling covariance matrix and the joint steering vector of the spatial-temporal-polarization domain, specifically including: According to the formula Calculate the space-time-polarization joint spectrum estimate of the five-dimensional joint basic subband unit in the space-time-polarization domain; in, The space-time polarimetric joint spectrum estimate of the five-dimensional joint basic subband unit in the space-time polarimetric domain. Let u be the pitch angle. Let v be the azimuth angle. For the b-th frequency, For the i-th polarization amplitude ratio, Let j be the polarization phase difference; It is the conjugate transpose of the joint steering vector of the space-time-polarization domain; is the inverse of the sampling covariance matrix.

7. The method for space-time-polarization domain beam nulling broadening of a planar vector array antenna according to claim 6, characterized in that, The spatiotemporal-polarimetric joint spectrum estimate within the beam nulling region is reset to the maximum value corresponding to each frequency subband, and the spatiotemporal-polarimetric domain interference covariance matrix is ​​reconstructed, specifically including: Using formula Reconstructing the space-time-polarization domain disturbance covariance matrix; in, The space-time-polarization domain interference covariance matrix; This represents the beam null broadening region corresponding to the Jth interference signal; The value is the estimated value of the space-time-polarization joint spectrum after resetting within the beam null broadening region. The pitch angle, It is the azimuth angle. For frequency, parameters Indicates the first The polarization domain parameters of the interference signal, where Indicates the polarization amplitude ratio, Indicates polarization phase difference; The space-time-polarization joint steering vector for each five-dimensional joint basic sub-band unit of the space-time-polarization domain within the beam nulling region; GF is the conjugate transpose of the space-time-polarization joint steering vector; L is the total number of interfering signals; GF is the number of frequency sub-bands within the beam null widening region; GP is the number of elevation angle cells within the beam null widening region; GA is the number of azimuth angle cells within the beam null widening region. The spatiotemporal polarimetric joint spectrum estimate is the value of any spatiotemporal polarimetric joint five-dimensional joint basic subband cell in the spatiotemporal polarimetric domain within the beam nulling region after resetting. Let the elevation angle be any five-dimensional joint basic sub-band unit of the space-time-polarization domain within the beam nulling region. For any five-dimensional joint basic sub-band unit of the space-time-polarization domain within the beam nulling region, For the first The starting frequency of the interference signal, For frequency sub-bands, The frequency width of the division; The space-time-polarization joint steering vector for any five-dimensional joint basic sub-band unit of the space-time-polarization domain within the beam nulling region; It is the conjugate transpose of the space-time-polarization joint steering vector; The width of the pitch angle is defined; The azimuth width is defined by the division. This represents the maximum value of the space-time-polarization joint spectrum estimate corresponding to each frequency within the beam null broadening region; The spatial steering vector for any five-dimensional joint basic sub-band unit of the space-time-polarization domain within the beam nulling region; For Kronecker product; The polarization domain steering vector for any five-dimensional joint basic sub-band unit of the space-time-polarization domain within the beam nulling region; H is the time-domain steering vector of any five-dimensional joint basic subband unit of the space-time-polarization domain within the beam nulling region; H is the conjugate transpose.

8. The method for space-time-polarization domain beam nulling broadening of a planar vector array antenna according to claim 1, characterized in that, The sampling covariance matrix is ​​subjected to eigenvalue decomposition to reconstruct the noise covariance matrix, specifically including: The sampling covariance matrix is ​​subjected to eigenvalue decomposition, and the minimum eigenvalue is used as the noise signal power estimate. The formula is then applied. Reconstruct the noise covariance matrix; in, Here is the noise covariance matrix; This is an estimate of the noise signal power. The smallest eigenvalue of the sampling covariance matrix; It is a 2MK-dimensional identity matrix.

9. The method for space-time-polarization domain beam nulling broadening of a planar vector array antenna according to claim 8, characterized in that, Reconstructing the joint interference and noise covariance matrix in the space-time-polarization domain based on the space-time-polarization domain interference covariance matrix and the noise covariance matrix specifically includes: According to the formula Reconstruct the joint interference and noise covariance matrix in the space-time-polarization domain; in, The covariance matrix of joint interference and noise in the space-time-polarization domain; The space-time-polarization domain interference covariance matrix; This represents the beam null broadening region corresponding to the Jth interference signal; The estimated value of the space-time-polarization joint spectrum after resetting within the beam nulling broadening region; The space-time-polarization joint steering vector for each basic sub-band unit within the beam nulling region; It is the conjugate transpose of the space-time-polarization joint steering vector.

10. The method for space-time-polarization domain beam nulling broadening of a planar vector array antenna according to claim 9, characterized in that, The weight vectors of all planar vector array antennas are solved based on the joint interference-noise covariance matrix in the space-time-polarization domain, specifically including: According to the formula Solve for the weight vectors of all planar vector array antennas; where, For weight vectors; These are constraints; This is the conjugate transpose of the constraint condition; These are constraint values.

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