Source separation for microphone arrays using multichannel conjugate gradient techniques

J. A. Beracoechea; S. Torres-Guijarro; E. Terleira; L. Ortiz; F. J. Casajús; Lino García
DAFx-2005 - Madrid
This paper proposes a new scheme to improve the source separation problem aimed to microphone array applications like WFS based teleconference systems. A multichannel, sub-band approach to reduce computational complexity is presented. Also, instead of using the LMS adaptive algorithm, a new system based on hybrid Conjugate Gradient-nLMS techniques is developed to accelerate the convergence time. This adaptive algorithm is controlled by a voice activity detector block that basically detects double talk situations and freezes the adaptation process to avoid the appearance of sound artifacts which may cause a significant degradation of the recovered signals and have a great impact in the quality of the full system.