Polar coordinate based nonlinear function for frequency-domain blind source separation
Hiroshi Sawada, Ryo Mukai, Shoko Araki, Shoji Makino · IEEE International Conference on Acoustics Speech and Signal Processing · 2002
This paper presents a new type of nonlinear function for independent component analysis to process complex-valued signals, which is used in frequency-domain blind source separation. The new function is based on the polar coordinates of a complex number, whereas the conventional one is based on the Cartesian coordinates. The new function is derived from the probability density function of frequency-domain signals that are assumed to be independent of the phase. We show that the difference between the two types of functions is in the assumed densities of independent components. Experimental results for separating speech signals show that the new nonlinear function behaves better than the conventional one.