Robust phase replication method for spatial aliasing problem in multiple sound sources localization
Kainan Chen, Jürgen T. Geiger, Wenyu Jin, Mohammad Javad Taghizadeh, Walter Kellermann · 2017
Most of multichannel sound source Direction Of Arrival (DOA) estimation algorithms suffer from spatial aliasing problems. The Interchannel Phase Differences (IPDs) are wrapped beyond the spatial aliasing frequency. This invalidates the DOA estimation due to significant errors. A real-time algorithm is proposed to address the general IPD wrapping problem for both single-source and multi-source scenarios. The algorithm comprises two steps, IPD replication and denoising. In the first step, the obtained IPDs are replicated to all the possible 2n-periodic repetitions, thus performing the correct unwrapping while introducing errors inevitably. However, the replication can also emphasize the correct DOAs of the sources when the replicated matrix is transformed into a histogram. The second step contains a post-processing method supporting our method more robust for a noisy environment. A theoretical analysis and experimental results with simulations and real recordings show the robustness of our method.