Two-Dimensional DOA Finding Method for Noncircular Signals with Unknown Mutual Coupling of Rectangular Arrays

Noncircular signals have promising application potential in array signal processing, especially for 2D direction finding. However, the performance of the existing algorithms for 2D DOA (Direction of Arrival) finding will be downgraded because of the unknown mutual coupling of arrays. On the other hand, most existing algorithms search in two-dimensional space, which requires a lot of computation. To address these problems, a two-dimensional DOA finding algorithm for noncircular signal sources under the condition of unknown mutual coupling of uniform rectangular array is proposed in this paper. Based on uniform rectangular array, the 2D spectral peak search is transformed to two-level 1D spectral peak search for estimation, which greatly reduces the computational complexity. At the same time, the noncircular signal is introduced, and the performance of the maximum estimation source number and parameter estimation can be improved by making use of its noncircular characteristics. Simulation results certificate both the low calculational complication and the efficiency of the proposed algorithm for noncircular sources parameter estimation.