Relaxation of rank-1 spatial constraint in overdetermined blind source separation

In this paper, we propose a new algorithm for overdetermined blind source separation (BSS), which enables us to achieve good separation performance even for signals recorded in a reverberant environment. The proposed algorithm utilizes ex tra observations (channels) in overdetermined BSS to esti mate both direct and reverberant components of each source. This approach can relax the rank-1 spatial constraint, which corresponds to the assumption of a linear time-invariant mixing system. To confirm the efficacy of the proposed algorithm, we apply the relaxation of the rank-1 spatial constraint to con ventional BSS techniques. The experimental results show that the proposed algorithm can avoid the degradation of separation performance for reverberant signals in some cases.