Direction estimation of coherent signals based on the symmetry of uniform linear array

Abstract

A large number of coherent signals are generated due to interface reflection in the ocean. A novel algorithm based on the symmetry of uniform linear array (ULA) is proposed to solve the problem of direction of arrival (DOA) estimation in coherent environment. Considering the center sensor as the reference, ULA can be divided into two symmetric parts. Firstly, the conjugate data of one part is rearranged, meanwhile, the other part data is maintained. Secondly, the correlation function calculated by processed data is averaged to construct a full rank Hermitian Toeplitz matrix. Finally, we can estimate the directions of coherent sources by eigen-decomposition. The results of simulation show that the proposed algorithm not only can effectively distinguish coherent signals, but also can improve the resolution, the accuracy and the probability of success in DOA estimation. Furthermore, the proposed algorithm is robust in the case of lower SNR or fewer snapshots.