2D DOA estimation algorithm with increased degrees of freedom for two parallel linear arrays

In this paper, a two-dimensional (2D) direction-of-arrival (DOA) estimation algorithm with increased degrees of freedom for two parallel linear arrays is presented. Being different from the conventional two-parallel linear array, the proposed two-parallel linear array consists of two uniform linear arrays with non-equal inter-element spacing. Propagator method (PM) is used to obtain a special matrix which can be utilized to increase the virtual elements of one of uniform linear arrays. Then, the PM algorithm is used again to obtain automatically paired elevation and azimuth angles. The simulation results and complexity analysis show that the proposed method can increase the number of distinguishable signals and improve the estimation precision without increasing the computational complexity.