DOA Estimation Algorithm for Strictly Noncircular Sources with Unknown Mutual Coupling

In this letter, an ESPRIT-based algorithm is proposed to handle the direction of arrival (DOA) estimation problem for strictly noncircular sources with unknown mutual coupling. At the cost of auxiliary elements, the structure of original mutual coupling matrix is compensated, and the unknown mutual coupling coefficients are separated from the distorted steering vector to obtain the ideal steering vector. Based on noncircularity, an extended received data is constructed by combining the received data and its conjugate counterpart. After that, ESPRIT framework is applied to the extended received data, and its key point is to utilize the diagonal relationship between the transformed manifold and the ideal manifold. Simulation results show that the proposed algorithm achieves larger virtual array aperture and comparable accuracy.