DOA Estimation and Self-Calibration Algorithm for Y-Shaped Array in the Presence of Mutual Coupling

A 2D DOA estimation algorithm in the presence of unknown mutual coupling for Y-shaped array based on MUSIC algorithm is presented and performance comparison among ULA, L-shaped array and Y-shaped array is analyzed. This algorithm can simultaneously estimate DOA of signals and coupling coefficients of antenna array without any calibration sources or iterative operations. It not only calibrates mutual coupling of the inner-subarrays, but also compensates for mutual coupling between subarrays. Compared with conventional self-calibration algorithm based on iterative alternating minimization technique, the proposed algorithm transforms joint estimation problem about DOA and mutual coupling coefficients into cascaded estimation problem, so as to avoid huge computation because of multi-dimensional search and global convergence problem due to iterative. Simulation results demonstrate that the performance of Y-shaped array is the best among three arrays and that the proposed self-calibration algorithm can achieve the high resolution under the condition of unknown coupling.