A Main Lobe Interference Suppression Method Based on Sum-difference Beam Dimensionality Reduction

Abstract

The invention belongs to the technical field of radar, and discloses a mainlobe jamming suppression method based on sum-difference beam dimension reduction. The method comprises the steps that a uniform linear array with N array elements is built, beam pointing and beam width of the uniform linear array are obtained, and one target and at least one mainlobe jamming exist in a beam mainlobe; a received signal of the uniform linear array is obtained; according to the beam pointing and the beam width, a weight vector of a sum beam and a weight vector of a difference beam are determined; dimension reduction is conducted on the received signal of the uniform linear array according to the weight vector of the sum beam, and a signal subjected to sum beam dimension reduction is obtained; dimension reduction is conducted on the received signal of the uniform linear array according to the weight vector of the difference beam, and a signal subjected to difference wave dimension reduction is obtained; a filtering weight coefficient is determined, according to the filtering weight coefficient, the signal subjected to sum beam dimension reduction and the signal subjected to difference wave dimension reduction, a signal subjected to mainlobe jamming suppression is obtained, and suppression of mainlobe jamming can achieve better performance.

Description

technical field [0001] The invention belongs to the technical field of radar, in particular to a main lobe interference suppression method based on sum-difference beam dimensionality reduction, which is used for radar anti-interference. Background technique [0002] In a complex signal environment, not only the desired signal but also a large number of interference signals exist. When the interference signal is stronger than the desired signal, the desired signal in the output of the array will be covered by the interference signal. To reduce the influence of interfering signals, the best way is to make the zero position of the array antenna pattern always point to the direction of interfering signals, and at the same time ensure that the main lobe is aligned with the desired signal direction. Since both the interference signal direction and the desired signal direction are unknown, the array antenna pattern is required to satisfy the above requirements adaptively. The beam...

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Problems solved by technology

However, jamming can also enter from the main lobe, such as self-defense jamming

When there is main lobe interference in the space, the antenna pattern obtained by adaptive beamforming will have two defects: one is that the side lobe level increases, and the other is that the main beam is seriously deformed

[0005] Li Rongfeng and others proposed an adaptive beamforming method (EMP algorithm) based on feature space orthogonal projection preprocessing on pages 50 to 53 of the journal "Modern Radar" in 2002, Volume 24, Issue 3. The method first uses the received interference data to obtain the covariance matrix of the interference, and obtains the signal subspace of the main lobe interference through eigendecomposition, and suppresses the main lobe interference through orthogonal projection preprocessing, and then preprocesses the orthogonal projection The obtained output signal is subjected to conventional adaptive beamforming to obtain the final adaptive antenna pattern; this method can solve the problem of side lobe level rise and main beam deformation when there is main lobe interference in space, but the disadvantage is that when the main lobe interferes When the lobe interference direction is close to the desired signal direction, the direction of the main beam will still shift, and when there are multiple main lobes in the space, the performance of the spatial filtering of this method will be seriously degraded;

[0006] Su Baowei et al. proposed an adaptive beamforming method based on blocking matrix preprocessing on pages 1830 to 1832 of the journal "System Engineering and Electronic Technology", Volume 27, Issue 11, 2005. This method estimates The direction of the main lobe interference, design a blocking matrix to suppress the main lobe interference, and then perform conventional adaptive beamforming to obtain an adaptive antenna pattern; this method can solve the problem of side lobe level increase and main beam deformation, but the disadvantages It is necessary to accurately estimate the direction of the main lobe interference

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