A sparse representation method for DOA estimation of coherent signals with mutual coupling

This paper presents a sparse representation method for direction of arrival (DOA) estimation of coherent signals in the presence of unknown mutual coupling. Making use of the special structure of the mutual coupling matrix for uniform linear arrays (ULAs), we formulate the problem of DOA estimation of coherent signals with mutual coupling as an over-complete basis representation problem, where its solution is subject to a block-sparse one. The new method is distinctly different from the improved spatial smoothing method, for the reason that spatial smoothing technique is no longer required. Since the whole array, instead of the middle subarray, is used for DOA estimation of coherent signals, the proposed method can achieve a better performance.