Second-order blind source separation in the Fourier space of data

A variant of the second-order blind identification (SOBI) algorithm is described. It achieves blind source separation of data whose inverse Fourier transform presents the required correlation properties. In a former approach, mixtures were separated using an inverse FT-SOBI-FT processing sequence. The same result is obtained using a new algorithm, named f-SOBI, based on an indirect evaluation of signal correlation functions. The relationship between both approaches is discussed. Their equivalence is established when an appropriate definition of correlation functions in SOBI is used, instead of the currently implemented one.