A Real-valued Approach for Wideband DOA Estimation Using Spherical Arrays

Direction of arrival (DOA) estimation of wideband signals is considered of great importance in array signal processing. In order to estimate both azimuth and elevation angles with good performance, a spherical array is used to capture the space signal information. Considering the property of spherical harmonic function, we propose a unitary transformation and two-step smoothing to turn the complex-valued direction matrix into a real-valued one. Compared with other algorithms, the proposed approach can achieve better performance especially when the number of snapshot is small. Simulations can certify the robustness and effectiveness of the proposed method.