Beamspace based DOA estimation methods of coherent sources in the presence of impulsive noise

This paper is concerned with the direction of arrival (DOA) estimation of coherent sources in impulse noise fields modeled as symmetric alpha stable (S alpha S) distribution. Robust covariation based MUSIC (ROC-MUSIC) and Fractional lower moment based MUSIC (FLOM-MUSIC) cannot be used to estimate the DOA under these conditions. Firstly, new forward-backward smoothing (FBS)-covariation matrices and FBS-FLOM matrices are defined by applying the spatial smoothing idea to covariation matrices and FLOM matrices. Two new algorithms based on FBS-covariation matrices and FBS-FLOM matrices are presented in the meantime. Then, the two algorithms are generalized to beamspace, and other two new algorithms called BROC-SS and BFLOM-SS are proposed. Theoretical analysis shows that noise subspace can be estimated by the eigen-decomposition of covariation matrices and FLOM matrices in both element space and beamspace so as to estimate the DOA of coherent sources in impulse noise. Moreover, performance of four new algorithms is analyzed by comparison. Computer simulation results verify the correctness and effectiveness of the proposed methods.