First-Order Relative Harmonic Coefficient-Based Time-Frequency Points Selection for Multi-Source DOA Estimation

As a research focus within the field of array signal processing, multi-source direction-of-arrival (DOA) estimation in enclosed environments has been paid much attention. Contaminated by reverberation, noise, and inter-source interference, DOA estimation become challenging. Hence it is essential to identify time-frequency (TF) points dominated by only one source to alleviate these issues. This paper proposes a TF point selection method for DOA estimation based on the first-order relative harmonic coefficient (RHC). This is first analyzed on the “point” level from two perspective, and we design an adaptive single-source dominant zone (SSDZ) detection method. Subsequently, the relationship between first- and zero-order RHC magnitudes of different types of TF points is explored, and we develop a simple but useful rule to further select TF points in the detected SSDZs. Finally, we adopt two-dimensional (2-D) kernel density estimation (KDE) and peak search to estimate the DOAs of sources after calculating the angles of the detected TF points. The effectiveness and robustness of the proposed method are verified and compared with the reference methods through experiments with both the simulated and real-world recordings.