Decoupled direction-of-arrival estimations using relative harmonic coefficients

Traditional source direction-of-arrival (DOA) estimation algorithms generally localize the elevation and azimuth simultaneously, requiring an exhaustive search over the two-dimensional (2-D) space. By contrast, this paper presents two decoupled source DOA estimation algorithms using a recently introduced source feature called the relative harmonic coefficients. They are capable to recover the source's elevation and azimuth separately, since the elevation and azimuth components in the relative harmonic coefficients are decoupled. The proposed algorithms are highlighted by a large reduction of computational complexity, thus enable a direct application for sound source tracking. Simulation results, using both a static and moving sound source, confirm the proposed methods are computationally efficient while achieving competitive localization accuracy.