DOA estimation with uniform linear arrays in the presence of mutual coupling via blind calibration

Direction-of-arrival (DOA) estimation in the presence of mutual coupling is a widely studied problem in the field of array signal processing. Most of the previous methods tried to estimate the DOAs by compensating the effect of mutual coupling with measured antenna impedances, which is not an effective way because the impedances are often time-variant.A blind calibrating method is proposed in this paper to deal with the problem of DOA estimation with uniform linear arrays in the presence of mutual coupling. This method exploits the complex symmetric Toeplitz form of the mutual coupling matrix (MCM) of unitary linear arrays (ULA), and transforms conventional direction finding methods from testing the orthogonality between the signal and noise subspaces to checking the rank deficiency of a projected matrix, eliminating most of the influence brought in by the effect of mutual coupling. Simulation results are presented to show the satisfying performance of the new method.