Efficient DOA Estimation Algorithm for Noncircular Sources Under Unknown Mutual Coupling

Mutual coupling effects may seriously degrade the direction-of-arrival (DOA) estimation performance in practical sensor arrays. In this article, a computationally efficient DOA estimation algorithm is proposed for noncircular sources in the presence of mutual coupling. Utilizing the noncircularity of the sources, we first construct an extended covariance matrix. Then, based on the banded symmetric Toeplitz structure of the mutual coupling matrix, the extended covariance matrix is divided into two submatrices. By simultaneous singular-value decomposition (SVD) of the two submatrices, the DOA parameter is obtained in a closed form. The proposed algorithm can improve the DOA estimation performance. Moreover, it is computationally efficient since it does not require any spectral search and avoids high-order statistics. Simulation results demonstrate both the efficiency and the effectiveness of our proposed algorithm under unknown mutual coupling.