A Blind Direction of Arrival and Mutual Coupling Estimation Scheme for Nested Array

Generally, nested array (NA) is susceptible to mutual coupling due to the dense subarray, which seriously degrades the performance. To address this issue, we design an array switching-based scheme to achieve the blind direction of arrival (DOA) and mutual coupling estimation in this paper. Specifically, by exploiting the inherent sparse structural characteristics of NA, we first switch the sparse subarray on to perform initial DOA estimation, which enables to offer the well-performed estimates free from the severe mutual coupling effect. Subsequently, the unambiguous angles are determined with low complexity by utilizing the received signal of the whole NA. Furthermore, the contaminated steering vector is reconstructed and a quadratic optimization problem is established to estimate the mutual coupling coefficients. Finally, re-estimation is conducted to obtain the refined estimates. Numerical simulations demonstrate the superiority of the proposed scheme.