Two-Dimensional Direction of Arrival Estimation for Coprime Planar Arrays via Polynomial Root Finding Technique

In this paper, the problem of 2-D direction-of-arrival (2-D-DOA) estimation for coprime planar arrays is investigated, and a method based on the polynomial root finding technique with high accuracy and computational efficiency is proposed. In conventional methods, the whole coprime planar array is usually divided into two subarrays to individually estimate 2-D-DOA, and then the true 2-D-DOA can be distinguished from the ambiguous result utilizing the coprime property. Different from the conventional methods, the proposed method utilizes the signal space and noise space of all data to improve the estimation accuracy. In addition, the computational complexity is reduced by converting the 2-D spectral peak searching problem into double polynomial root finding problem. Furthermore, the matching error is eliminated in the scenario of multiple targets. Simulation results demonstrate that the proposed method achieves not only higher estimation accuracy but also lower computational complexity over conventional methods.