阅读说明：本技术 基于协方差矩阵重构的卫星导航动态抗干扰方法及其系统 (Satellite navigation dynamic anti-interference method and system based on covariance matrix reconstruction ) 是由 李武涛 于 2021-06-16 设计创作，主要内容包括：本发明公开了一种基于协方差矩阵重构的卫星导航动态抗干扰方法及其系统,包括：构造用于接收干扰信号与导航信号的均匀圆阵,获取基带信号；根据所述基带信号的快拍数据进行自相关处理,得到所述基带信号在无干扰抑制的初始状态下的协方差矩阵的估计值；采用多重信号分类算法对所述初始状态下的协方差矩阵的估计值进行处理,以构造谱函数；对所述谱函数按照加窗原理进行空域扩展及零陷深度控制,利用所述空域扩展及零陷深度控制结果对所述初始状态下的协方差矩阵进行重构处理,根据最小方差无失真响应的解,得到所述均匀圆阵在干扰方向的零陷深度和宽度,以确定干扰抑制的程度。本发明能够有效抑制载体动态条件下的干扰信号,其抗干扰性能优异。(The invention discloses a satellite navigation dynamic anti-interference method and a system thereof based on covariance matrix reconstruction, comprising the following steps: constructing a uniform circular array for receiving interference signals and navigation signals and acquiring baseband signals; performing autocorrelation processing according to the snapshot data of the baseband signal to obtain an estimated value of a covariance matrix of the baseband signal in an initial state without interference suppression; processing the estimated value of the covariance matrix in the initial state by adopting a multiple signal classification algorithm to construct a spectrum function; and carrying out space domain expansion and null depth control on the spectrum function according to a windowing principle, carrying out reconstruction processing on the covariance matrix in the initial state by using the space domain expansion and null depth control result, and obtaining the null depth and width of the uniform circular array in the interference direction according to the solution of minimum variance distortionless response so as to determine the degree of interference suppression. The invention can effectively inhibit interference signals under the dynamic condition of the carrier, and has excellent anti-interference performance.)

1. A satellite navigation dynamic anti-interference method based on covariance matrix reconstruction is characterized by comprising the following steps:

constructing a uniform circular array for receiving interference signals and navigation signals, and performing baseband processing by using the interference signals and the navigation signals received by each array element of the uniform circular array to obtain baseband signals;

performing autocorrelation processing according to the snapshot data of the baseband signal to obtain an estimated value of a covariance matrix of the baseband signal in an initial state without interference suppression;

processing the estimated value of the covariance matrix in the initial state by adopting a multiple signal classification algorithm according to the mathematical relationship between the direction vector of the navigation signal and the direction vector of the interference signal to construct a spectrum function;

performing space domain expansion and null depth control on the spectrum function according to a windowing principle, and performing reconstruction processing on the covariance matrix in the initial state by using the space domain expansion and null depth control result to obtain a preprocessing value of the covariance matrix of the baseband signal in the current state without interference suppression;

and obtaining the null depth and width of the uniform circular array in the interference direction according to the solution of the minimum variance distortionless response based on the preprocessing value of the covariance matrix of the baseband signal in the current state of interference-free suppression so as to determine the degree of interference suppression.

2. The dynamic satellite navigation anti-jamming method based on covariance matrix reconstruction of claim 1, characterized in that the uniform circular matrix comprises: a plurality of L-band right-hand circularly polarized antenna units are uniformly distributed on a circular dielectric substrate, and the spacing between the array element units is equal and equal to half wavelength.

3. The dynamic satellite navigation anti-jamming method based on covariance matrix reconstruction of claim 1, characterized in that the jamming signal is a suppressed jamming signal.

4. The dynamic satellite navigation anti-jamming method based on covariance matrix reconstruction as claimed in claim 1, characterized in that Hanning window is used to perform spatial domain expansion and null depth control on the spectral function.

5. The dynamic satellite navigation anti-jamming method based on covariance matrix reconstruction of claim 1, characterized in that the baseband processing comprises: down conversion and low pass filtering.

6. The dynamic satellite navigation anti-jamming method based on covariance matrix reconstruction of claim 1, characterized in that the snapshot data of the baseband signal is obtained by band-pass sampling.

7. The dynamic satellite navigation disturbance rejection method based on covariance matrix reconstruction of claim 1, wherein the null depth control is performed by adding a depth coefficient.

8. The dynamic satellite navigation anti-jamming method based on covariance matrix reconstruction according to claim 7, characterized in that the solving according to the least square error undistorted response comprises obtaining optimized weight vectors.

9. The dynamic satellite navigation interference rejection method based on covariance matrix reconstruction of claim 8, wherein the optimized weight vector minimizes the output power of the uniform circular matrix.

10. A satellite navigation dynamic anti-interference system based on covariance matrix reconstruction is characterized by comprising:

the system comprises an acquisition module, a processing module and a processing module, wherein the acquisition module is used for constructing a uniform circular array for receiving interference signals and navigation signals, and performing baseband processing by using the interference signals and the navigation signals received by each array element of the uniform circular array to acquire baseband signals;

the estimation module is used for carrying out autocorrelation processing according to the snapshot data of the baseband signal to obtain an estimation value of a covariance matrix of the baseband signal in an initial state without interference suppression;

the resolving module is used for processing the estimated value of the covariance matrix in the initial state by adopting a multiple signal classification algorithm through the mathematical relationship between the direction vector of the navigation signal and the direction vector of the interference signal so as to construct a spectrum function;

the control module is used for carrying out space domain expansion and null depth control on the spectrum function according to a windowing principle, and carrying out reconstruction processing on the covariance matrix in the initial state by using the space domain expansion and null depth control result to obtain a preprocessing value of the covariance matrix of the baseband signal in the current state without interference suppression;

and the determining module is used for obtaining the null depth and the width of the uniform circular array in the interference direction according to the solution of the minimum variance distortionless response based on the preprocessing value of the covariance matrix of the baseband signal in the current state without interference suppression so as to determine the degree of interference suppression.

Technical Field

The invention belongs to the technical field of satellite navigation anti-interference, and particularly relates to a satellite navigation dynamic anti-interference method and a satellite navigation dynamic anti-interference system based on covariance matrix reconstruction.

Background

Conventional adaptive beamforming algorithms are usually derived in an ideal environment. However, in increasingly complex practical environments, the performance of the conventional adaptive beamforming algorithm is greatly reduced due to channel errors, array position errors, mutual coupling and other factors.

In the military field, most satellite navigation receiver carriers are in a high-speed motion state, and if a spatial filtering algorithm is directly adopted, interference is easily moved out of a null or is not in the deepest position of the null, so that the interference under the dynamic state cannot be effectively inhibited. The current common treatment method is to widen the null. The widened null method based on differential constraint has the problem of consuming anti-interference freedom. In addition, the prior art also adopts a covariance matrix tapering algorithm for processing, but the obvious defects are that: the depth of the null is reduced while the null is widened, so that the strong interference resistance is reduced.

Disclosure of Invention

The invention aims to provide a satellite navigation dynamic anti-interference method and a satellite navigation dynamic anti-interference system based on covariance matrix reconstruction, and solves the problem that the anti-interference performance is reduced in the traditional null broadening algorithm.

In view of this, the present invention provides a dynamic satellite navigation anti-interference method based on covariance matrix reconstruction, which is characterized by comprising:

constructing a uniform circular array for receiving interference signals and navigation signals, and performing baseband processing by using the interference signals and the navigation signals received by each array element of the uniform circular array to obtain baseband signals;

performing autocorrelation processing according to the snapshot data of the baseband signal to obtain an estimated value of a covariance matrix of the baseband signal in an initial state without interference suppression;

processing the estimated value of the covariance matrix in the initial state by adopting a multiple signal classification algorithm according to the mathematical relationship between the direction vector of the navigation signal and the direction vector of the interference signal to construct a spectrum function;

performing space domain expansion and null depth control on the spectrum function according to a windowing principle, and performing reconstruction processing on the covariance matrix in the initial state by using the space domain expansion and null depth control result to obtain a preprocessing value of the covariance matrix of the baseband signal in the current state without interference suppression;

and obtaining the null depth and width of the uniform circular array in the interference direction according to the solution of the minimum variance distortionless response based on the preprocessing value of the covariance matrix of the baseband signal in the current state of interference-free suppression so as to determine the degree of interference suppression.

Further, the uniform circular array comprises: a plurality of L-band right-hand circularly polarized antenna units are uniformly distributed on a circular dielectric substrate, and the spacing between the array element units is equal and equal to half wavelength.

Further, the interference signal is a suppressed interference signal.

Further, a Hanning window is adopted to carry out spatial domain expansion and null depth control on the spectrum function.

Further, the baseband processing includes: down conversion and low pass filtering.

Further, the snapshot data of the baseband signal is obtained by band-pass sampling.

Further, the null depth control is performed by adding a depth coefficient.

Further, obtaining an optimized weight vector according to the solution of the least square error undistorted response.

Further, the optimized weight vector minimizes the output power of the uniform circular array.

Another object of the present invention is to provide a dynamic anti-jamming system for satellite navigation based on covariance matrix reconstruction, which comprises:

the system comprises an acquisition module, a processing module and a processing module, wherein the acquisition module is used for constructing a uniform circular array for receiving interference signals and navigation signals, and performing baseband processing by using the interference signals and the navigation signals received by each array element of the uniform circular array to acquire baseband signals;

the estimation module is used for carrying out autocorrelation processing according to the snapshot data of the baseband signal to obtain an estimation value of a covariance matrix of the baseband signal in an initial state without interference suppression;

the resolving module is used for processing the estimated value of the covariance matrix in the initial state by adopting a multiple signal classification algorithm through the mathematical relationship between the direction vector of the navigation signal and the direction vector of the interference signal so as to construct a spectrum function;

the control module is used for carrying out space domain expansion and null depth control on the spectrum function according to a windowing principle, and carrying out reconstruction processing on the covariance matrix in the initial state by using the space domain expansion and null depth control result to obtain a preprocessing value of the covariance matrix of the baseband signal in the current state without interference suppression;

and the determining module is used for obtaining the null depth and the width of the uniform circular array in the interference direction according to the solution of the minimum variance distortionless response based on the preprocessing value of the covariance matrix of the baseband signal in the current state without interference suppression so as to determine the degree of interference suppression.

The invention achieves the following significant beneficial effects:

the satellite navigation dynamic anti-interference method based on covariance matrix reconstruction comprises the following steps: constructing a uniform circular array for receiving interference signals and navigation signals, and performing baseband processing by using the interference signals and the navigation signals received by each array element of the uniform circular array to obtain baseband signals; performing autocorrelation processing according to the snapshot data of the baseband signal to obtain an estimated value of a covariance matrix of the baseband signal in an initial state without interference suppression; processing the estimated value of the covariance matrix in the initial state by adopting a multiple signal classification algorithm according to the mathematical relationship between the direction vector of the navigation signal and the direction vector of the interference signal to construct a spectrum function; performing space domain expansion and null depth control on the spectrum function according to a windowing principle, and performing reconstruction processing on the covariance matrix in the initial state by using the space domain expansion and null depth control result to obtain a preprocessing value of the covariance matrix of the baseband signal in the current state without interference suppression; and obtaining the null depth and width of the uniform circular array in the interference direction according to the solution of the minimum variance distortionless response based on the preprocessing value of the covariance matrix of the baseband signal in the current state of interference-free suppression so as to determine the degree of interference suppression. A windowing function is used for carrying out spatial domain expansion on a spatial spectrum function, then the expanded spectrum function is used for reconstructing an array covariance matrix, a depth coefficient is added for effectively controlling the depth of the null, and simulation experiment results show that the anti-interference performance of the method is improved by 20dB compared with that of a traditional null widening method.

In the satellite navigation dynamic anti-jamming system based on covariance matrix reconstruction, including: the system comprises an acquisition module, a processing module and a processing module, wherein the acquisition module is used for constructing a uniform circular array for receiving interference signals and navigation signals, and performing baseband processing by using the interference signals and the navigation signals received by each array element of the uniform circular array to acquire baseband signals; the estimation module is used for carrying out autocorrelation processing according to the snapshot data of the baseband signal to obtain an estimation value of a covariance matrix of the baseband signal in an initial state without interference suppression; the resolving module is used for processing the estimated value of the covariance matrix in the initial state by adopting a multiple signal classification algorithm through the mathematical relationship between the direction vector of the navigation signal and the direction vector of the interference signal so as to construct a spectrum function; the control module is used for carrying out space domain expansion and null depth control on the spectrum function according to a windowing principle, and carrying out reconstruction processing on the covariance matrix in the initial state by using the space domain expansion and null depth control result to obtain a preprocessing value of the covariance matrix of the baseband signal in the current state without interference suppression; and the determining module is used for obtaining the null depth and the width of the uniform circular array in the interference direction according to the solution of the minimum variance distortionless response based on the preprocessing value of the covariance matrix of the baseband signal in the current state without interference suppression so as to determine the degree of interference suppression. A windowing function is used for carrying out spatial domain expansion on a spatial spectrum function, then the expanded spectrum function is used for reconstructing an array covariance matrix, a depth coefficient is added for effectively controlling the depth of the null, and simulation experiment results show that the anti-interference performance of the method is improved by 20dB compared with that of a traditional null widening method.