Wideband DOA estimation based on a-shaped array

In the underwater passive target detection system, direction of arrival (DOA) estimation of traditional uniform linear array (ULA) becomes poor when targets come from the direction of end-fire. To solve this problem, this paper develops a new DOA estimation method for the wideband signal based on A-shaped array, which is implemented via two ULAs distributed with a specific angle. Firstly, the A-shaped array structure is introduced and the received wideband signal of the array is modeled. To deal with the wideband signal, the minimum variance distortionless response (MVDR) beam forming is applied based on sub-band decomposition to obtain the spatial spectrum accurately. Next, the directions of the targets are estimated by locating the position of spectral peaks. Simulation results shows that the proposed A-shaped array solution outperforms the traditional ULA in terms of higher accuracy, which sheds lights on the design of practial deployment of DOA estimation for underwater wideband signals.