A Recursive RARE Algorithm for DOA Estimation With Unknown Mutual Coupling

The effect of mutual coupling between array elements is known to substantially degrade direction-of-arrival (DOA) estimation performance. Rank-reduction (RARE) methods can eliminate the mutual coupling effect without loss of array aperture. However, they might yield serious ambiguous DOA estimates in some scenarios. This letter proposes a modified RARE algorithm for DOA estimation, which overcomes the problem of ambiguous estimation by recursively building up RARE matrices. Moreover, due to the utilization of an additional unique structure of mutual coupling coefficients, the new method can give a better DOA estimation performance. Simulation results verify the efficiency of the proposed method.