Robust adaptive beamforming method for non-Gaussian signals in Gaussian noise

Abstract

The invention discloses a robust adaptive beamforming method for non-Gaussian signals in Gaussian noise. The method comprises the following steps: firstly, diagonally loading a four-order cumulant matrix of an array receiving signal, reconstructing a more accurate steering vector of an expected signal and interference through a series of processes based on a Capon four-order spatial spectrum loaded diagonally, and generating a virtual signal covariance matrix and a virtual interference covariance matrix; then, for array receiving signals, calculating a local Capon spatial cross-power spectrum,and estimating a noise covariance matrix; and finally, obtaining an optimal weight vector by utilizing the obtained expected signal steering vector, the virtual interference covariance matrix and thenoise covariance matrix, and forming steady adaptive beam output for array receiving signals. According to the method, a Capon four-order spatial spectrum, a Capon spatial cross-power spectrum and diagonal loading and neighborhood optimization technologies are utilized in a combined mode, a more accurate and effective steering vector and interference and noise covariance matrix of an expected signal is obtained, and the robustness of the self-adaptive beam former is improved.

Description

technical field [0001] The invention relates to the field of beamforming research in the field of array signal processing, especially in the non-ideal situation where various errors may exist, aiming at the problem of robust adaptive beamforming of non-Gaussian signals in Gaussian white or colored noise, the joint use of fourth-order The cumulant matrix and covariance matrix generate Capon fourth-order space spectrum and Capon space cross-power spectrum, and combine with diagonal loading and neighborhood optimization techniques to obtain more accurate steering vectors of desired signals and more effective interference Adding the noise covariance matrix improves the robustness of the adaptive beamer. Background technique [0002] Among the existing robust adaptive beamforming methods, the more representative methods are: linear constrained minimum variance method, diagonal loading method, eigensubspace method and uncertain set method. However, considering the uncertainty of ...

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Problems solved by technology

However, this reconstruction method only directly uses the Capon space power spectrum to integrate the angle variable in the undesired signal angle region, and the final reconstructed interference-plus-noise covariance matrix is ​​not accurate enough, so that this method only has a certain effect on the direction of arrival error. robustness, the performance of the algorithm is not guaranteed in the presence of other types of steering vector errors

Subsequently, a method for reconstructing the interference-plus-noise covariance matrix for any type of array error was proposed. This method mainly changed the original linear integration region and transformed it into a space circular uncertainty set. The calculation is more complicated, and there are certain errors in the reconstruction process, and a more accurate interference plus noise covariance matrix cannot be obtained

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