Improved 2D direction of arrival estimation with a small number of elements in UCA in the presence of mutual coupling

Abstract

With a small number of elements in uniform circular arrays (UCAs), the performance of beamspace transformation (BT) based methods for 2D direction-of-arrival (DOA) estimation in the presence of mutual coupling suffers serious degradation. The performance breakdown is associated with the residual term which is introduced by the BT. To solve this problem, a novel algorithm which modifies the beamspace data is proposed in this paper. Based on the estimated azimuth angles obtained by a UCA-RARE-like method and the estimated elevation angles obtained by a new searching method, the beamspace data is iteratively revised by removing its residual component. Thus, unbiased 2D DOA estimates can be obtained depending on the revised beamspace data. Simulation results are given to verify the effectiveness of the proposed algorithm and a comparison is made with results from existed methods.