Robust adaptive beamforming method for asymmetric signals in symmetric noise

Abstract

The invention discloses a robust adaptive beamforming method for asymmetric signals in symmetric noise. The method comprises the following steps: firstly, constructing a full-space neighborhood errorvector table; secondly, diagonally loading a third-order cumulant matrix of the array receiving signal, estimating an expected signal and an initial value of each interference direction of arrival based on a Capon third-order spatial spectrum loaded diagonally, and determining an angle region set only containing noise; thirdly, estimating more accurate expected signals and interference steering vectors through adoption of a neighborhood optimization method, and generating a virtual interference covariance matrix; fourthly, receiving signals from the array, 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 the noise covariance matrix, and forming robust adaptive beam output for array receiving signals, thereby improving the robustness of the adaptive beam device.

Description

technical field [0001] The invention relates to the beamforming research field in the field of array signal processing, in particular to a robust adaptive beamforming method for asymmetrical signals in symmetric noise. 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 parameter selection and the constraints of the inherent nature of the algorithm itself, the performance of these beamforming methods will be significantly attenuated in the presence of array errors, and cannot achieve ideal results. [0003] In recent years, adaptive beamforming methods based on the reconstruction of the interference-plus-noise covariance matrix have been studied, which are more robust. This method mainly uses the Capon space power spectrum, and uses its integral in th...

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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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