A Frequency Domain Approach to Blind Identification of MIMO FIR Channels Driven by Non-Stationary Sources

In this paper we discuss a new method for blind identification of MIMO convolutive channels driven by white quasi-stationary sources. The sources can assume arbitrary probability distributions and in some cases they can even be all Gaussian distributed. We demonstrate that by using the second order statistics of the channel outputs, under mild conditions on the non-stationarity of sources, and under the condition that channel is column-wise co-prime, the impulse response of the MIMO channel can be identified up to an inherent scaling and permutation ambiguity. We also prove that by using the new algorithm, under the stated assumptions, a uniform permutation across all frequency bins is guaranteed and hence no post processing is required as is the case with previous frequency domain algorithms. Numerical simulations are presented to demonstrate the performance of the new algorithm.