Two-dimensional Off-Grid DOA Estimation with Improved Three-Parallel Coprime Arrays on Moving Platform

In this paper, two-dimensional (2-D) direction-of-arrival (DOA) estimation issue is investigated by constructing array model on moving platform. Based on the moving array model, we propose two improved three-parallel coprime arrays (TPCPAs), which utilize the redundancy in the physical structure of moving TPCPA (MTPCPA) and are able to generate the same virtual array as MTPCPA using much fewer sensors. Accordingly, higher sensor utilization is achieved by the proposed arrays, which can contribute to the increase in the number of degrees of freedom. Besides, with the proposed arrays, we also present a 2-D off-grid DOA estimation algorithm, in which the estimated 2-D angles are automatically paired without extra pairing procedure. Particularly, by utilizing the ℓ p ( 0 < p < 1 ) norm and majorization–minimization method jointly, the proposed algorithm solves the grid mismatch problem effectively and accordingly enhances the 2-D DOA estimation performance. Finally, numerical simulations demonstrate the effectiveness and superiority of the proposed arrays and 2-D off-grid DOA estimation algorithm.