Subspace tracking of multiple sources and its application to speakers extraction

In this paper we introduce a novel algorithm for extracting desired speech signals uttered by moving speakers contaminated by competing speakers and stationary noise in a reverberant environment. The proposed beamformer uses eigenvectors spanning the desired and interference signals subspaces. It relaxes the common requirement on the activity patterns of the various sources. A novel mechanism for tracking the desired and interferences subspaces is proposed, based on the projection approximation subspace tracking (deflation) (PASTd) procedure and on a union of subspaces procedure. This contribution extends previously proposed methods to deal with multiple speakers in dynamic scenarios.