An Autocalibration Algorithm for Uniform Circular Array with Unknown Mutual Coupling

A new subspace-based autocalibration algorithm for a uniform circular array with unknown mutual coupling is presented in this letter. In allusion to the existing ambiguity problems and the limitation of nonzero coupling coefficients in earlier work by Lin and Yang, a more generalized iterative method is proposed to jointly estimate the direction-of-arrival (DOA) and unknown mutual coupling. It suffers from no ambiguity problems and does not require the prior knowledge of the number of nonzero elements in the coupling vector. Simulation results show the robustness, effectiveness, and higher estimated accuracy of the proposed algorithm.