Batch-Online Semi-Blind Source Separation Applied to Multi-Channel Acoustic Echo Cancellation

Semi-blind source separation (SBSS) is a special case of the well-known blind source separation (BSS) when some partial knowledge of the source signals is available to the system. In particular, a batch adaptation in the frequency domain based on independent component analysis (ICA) can be effectively used to jointly perform source separation and multichannel acoustic echo cancellation (MCAEC) through SBSS without double-talk detection. Many issues related to the implementation of an SBSS system are discussed in this paper. After a deep analysis of the structure of the SBSS adaptation, we propose a constrained batch-online implementation that stabilizes the convergence behavior even in the worst case scenario of a single far-end talker along with the non-uniqueness condition on the far-end mixing system. Specifically, a matrix constraint is proposed to reduce the effect of the non-uniqueness problem caused by highly correlated far-end reference signals during MCAEC. Experimental results show that high echo cancellation can be achieved just as the misalignment remains relatively low without any preprocessing procedure to decorrelate the far-end signals even for the single far-end talker case.