A Low-complexity DOA Estimation Method for Nested Array via Root-MUSIC

The nested array results in a hole-free difference coarray (DCA) after virtualization, enhancing the utilization of virtual array elements. MUSIC algorithm is an algorithm with high estimation accuracy, but the angle search process has high complexity. In this paper, we propose a spatial smoothing root-MUSIC (SS-root-MUSIC) algorithm based on nested arrays to reduce complexity. Firstly, we obtain the equivalent signals of the DCA and recover the rank through virtualization and spatial smoothing. Then we use the root-MUSIC polynomial to get the DOA estimation results. The proposed SS-root-MUSIC has low computational complexity by avoiding the angle search process while ensuring the estimation accuracy. Theoretical and simulation results confirm the superiority of the proposed SS-root-MUSIC algorithm.