A Frequency Domain Approach to Blind Identification of MIMO FIR Systems Driven by Quasi-Stationary Signals

This paper discusses the problem of blind identification of MIMO convolutive channels when the sources are quasi-stationary. No other assumptions are made about the sources; i.e., they can be temporally white or colored and they can assume any distributions. We show that by using second order statistics of the channel outputs, under some mild conditions on the non-stationarity of sources and that the channel is column-wise coprime, identification can be achieved up to a scalar ambiguity and column permutation of the original MIMO channel. We also present an efficient, two step frequency domain algorithm for identifying the channel. To demonstrate the performance of the new algorithm numerical simulations are presented.