Reduced-Dimension DOA Estimation Based on MUSIC Algorithm in L-Shaped Array

According to the heavy computation and high cost of two-dimensional (2D) multiple signal classification (MUSIC) to achieve 2D direction of arrival (DOA) estimation in various complex arrays, this paper proposes a reduced-dimensional (RD) estimation algorithm based on L-shaped uniform array without the need of 2D spectral peak search and secondary optimization. This algorithm makes full use of the structural characteristics of L-shaped array, decomposes the L-shaped uniform array into two uniform linear arrays, and estimates the angle between the source and the X-axis and Y-axis by one-dimensional (1D) search respectively, then obtains the 2D-DOA estimation according to the geometric relationship and uses the maximum likelihood method for angle matching. In this algorithm, the time-consuming 2D search is transformed into 1D search, which greatly reduces the computational complexity. In order to further reduce the complexity and improve the estimation accuracy, the root-finding method can be used instead of one-dimensional search. The simulation results show that the proposed algorithm has higher DOA estimation performance as well as faster operation speed.