Evaluation and Comparison of Three Source Direction-of-Arrival Estimators Using Relative Harmonic Coefficients

Abstract

A spherical harmonics domain source feature called relative harmonic coefficients (RHC) has recently been applied to address the source direction-of-arrival (DOA) estimation problem. This paper presents a compact evaluation and comparison between two existing RHC based DOA estimators: (i) a method using a full grid search over the two-dimensional (2-D) directional space, (ii) a decoupled estimator which uses one-dimensional (1-D) search to separately localize the source's elevation and azimuth. We also propose a new estimator using a gradient descent search over the 2-D directional grid space. Extensive experiments in both simulated and real-life environments are conducted to examine and analyze the performance of all the underlying DOA estimators. Two objective metrics, including localization accuracy and algorithm complexity, are adopted for an evaluation and comparison between all estimators.

Acoustic source localization in the spherical harmonics domain exploiting low-rank approximations

“…The RHCs can be thought of as the SHD counterpart of the relative transfer functions (RTF), containing the DOA information while being independent from the source signal and robust to noise. Different approaches exploiting RHC were published in the literature, including solutions based on grid search [22], gradient descent [23] and Gaussian process [21]. In [24,25], computationally efficient approaches employing a search decouple on azimuth and elevation were introduced, while [26] provides a closed-form solution limited to first-order SHD.…”