Joint DOD and DOA estimation of bistatic MIMO radar in the presence of unknown mutual coupling

In this paper, a decoupling-complex matrix (DCCM) method is proposed for joint direction of departure (DOD) and direction of arrival (DOA) estimation in the presence of unknown mutual coupling for bistatic MIMO radar system with orthogonal transmitted waveforms. The proposed method proceeds in two steps. First, the mutual coupling effect is compensated by setting the auxiliary elements on both sides of the transmitting and receiving uniform linear arrays (ULAs). Then, a complex matrix is constructed to estimate the DOD and DOA where the correct pairing is automatically given by the real and imaginary parts of complex eigenvalues. In addition, the mutual coupling coefficients can be solved in closed-form as a natural by-product of the DOD and DOA estimates. The effectiveness of our method is demonstrated with numerical simulations. The closed-form expressions for determined Cramér-Rao bounds (CRB) on angle and mutual coupling coefficient estimations are also derived. ► Decoupling-complex matrix method is proposed to estimate the DOD and DOA in the presence of unknown mutual coupling. ► Auxiliary elements is set to compensate the mutual coupling effect. ► Complex matrix is constructed to estimate the DOD and DOA. ► Closed-form expressions for Cramer-Rao bounds on angle and mutual coupling coefficient estimations are derived.