Regular overlapped sub-array-based adaptive beamforming method

Abstract

The invention discloses a regular overlapped sub-array-based adaptive beamforming method. The invention aims to solve the problems of high side lobe and low output signal to interference plus noise ratio in beamforming in the prior art. The realization process of the method includes the following steps that: 1) a uniform equidistant linear array element-level signal model is built; 2) regular overlapped sub-array division is performed on the equidistant linear array, a sub-array-level received signal model and a sub-array-level received signal correlation matrix are determined; 3) the sub-array-level received signal correlation matrix is transformed, eigenvalue decomposition is performed on the transformed sub-array-level received signal correlation matrix, small eigenvalues obtained through the eigenvalue decomposition are utilized to estimate noise power and a sub-array-level noise correlation matrix; 4) whitening processing is performed on the sub-array-level received signal correlation matrix according to the sub-array-level noise correlation matrix, so that a new correlation matrix can be formed; and 5) the new correlation matrix is utilized to perform adaptive beamforming based on a linearly constrained minimum variance criterion. With the method adopted, beam sidelobes are decreased, an output signal to interference plus noise ratio can be improved. The method can be used to process the influence of noises in a regular overlapped sub-array on beamforming.

Description

technical field [0001] The invention belongs to the technical field of radar, and specifically relates to an adaptive beam forming method, which can be used to deal with the influence of noise in regular overlapping subarrays on beam forming, so as to reduce beam side lobes and improve output signal-to-interference-noise ratio. Background technique [0002] The main research contents of array signal processing include adaptive beamforming and super-resolution direction of arrival estimation. Adaptive beamforming is also known as adaptive spatial filtering. Its essence is to enhance or suppress signals from different directions to obtain signals in the desired direction. It is widely used in radar, sonar, communication and other fields. [0003] Due to its wide application prospects, array signal processing algorithms have been developed rapidly in the past three decades, especially in the field of phased array radar, adaptive beamforming technology has been paid more and mor...

AI Technical Summary

Problems solved by technology

Compared with regular non-overlapping sub-arrays, regular overlapping sub-arrays can effectively reduce grating lobes by reducing the phase center distance between sub-arrays. The sharing of the sub-arrays also has an impact, and the obvious problem is that the noise between the sub-arrays is no longer independent of each other, which can be regarded as beamforming in the background of colored noise

[0011] For beamforming in the background of colored noise, most of the existing methods use the estimation of the noise correlation matrix to pre-whiten the received data. Although this can perform better beamforming, it will increase the beam sidelobe and reduce the output signal interference. noise ratio

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