Frequency-Domain Blind Source Separation.

This chapter discusses the frequency-domain approach to the blind source separation (BSS) of convolutively mixed acoustic signals. In this approach, independent component analysis (ICA) is employed in each frequency bin to calculate the frequency responses of separation filters. Since convolutive mixtures in the time domain can be approximated as multiple instantaneous mixtures in the frequency domain, the advantage of this approach is that ICA is applied just for instantaneous mixtures, which is very simple. However, the permutation ambiguity of ICA solutions then becomes a problem. This chapter mainly deals with a method for solving the permutation problem. The method utilizes the source location information that can be estimated from the ICA solutions. We also discuss other important topics for frequency-domain BSS, such as complex-valued ICA, scaling alignment and spectral smoothing. To show the effectiveness of this frequency-domain approach, we report experimental results for separating up to four sources with a 4-element linear array, and also six sources with an 8-element planar array. [ABSTRACT FROM AUTHOR]