DOA Estimation with Sparse Array under Unknown Mutual Coupling

In this paper, we propose a direction-of-arrival (DOA) estimation algorithm under unknown mutual coupling with a sparse linear array (SLA). We employ an SLA composed of two uniform linear arrays (ULA), and the element spacing of one of the subarrays is large enough to neglect the effect of the mutual coupling (MC). The fourth-order-cumulants (FOCs) of the received data from partial elements of the first subarray and all elements of the second subarray are exploited to construct a high-order FOC matrix. Then, the DOAs of incident signals are estimated by dealing with this high-order matrix. The array aperture is extended greatly due to the sparse structure. Hence, the proposed method shows much better performance than some classical blind DOA estimation methods in accuracy and resolution. We also propose some simulation results to prove the effectiveness of our method.