Two-Dimensional Off-Grid DOA Estimation Using Unfolded Parallel Coprime Array

A two-dimensional (2-D) off-grid direction of arrival (DOA) estimation method using unfolded parallel coprime array (UPCA) is proposed. The proposed UPCA ensures large inter-element spacing, which is robust to the mutual coupling problem, and 2-D DOA estimation problem is transformed into one dimensional sparse representation (SR), which reduces the computation complexity. Besides, the off-grid DOA problem is taken into account and compensated through joint sparse recovery, which only requires a rough grid. Without the prior knowledge of source number, the proposed algorithm achieves improved DOA estimation results while requiring reduced computation complexity when compared to other SR-based methods. Simulation results verify the effectiveness of the algorithm.