OPM and root-rare method based DOA estiamtion for ULA with mutual coupling

A low complexity direction of arrival (DOA) estimation algorithm for uniform linear array (ULA) with mutual coupling is proposed in this paper. The orthonormal propagator method (OPM) and root rank-reduction (RARE) method are introduced to supersede eigendecomposition and spectral peak searching. Moreover, the mutual coupling coefficients are estimated to improve the accuracy of estimated DOAs. Simulation results show that the proposed algorithm achieves excellent performance at moderate and high signal-to-noise ratio (SNR). And the poor performance at low SNR can be improved if the assumed number of sources is slightly overestimated. In case of strong mutual coupling, the estimated parameters performance performs well because all the array sensors are employed.