Blind paraunitary equalization

In this paper a blind multiple-input/multiple-output (MIMO) space–time equalizer is described, dedicated to convolutive mixtures when observations have been pre-whitened. Filters preserving space–time whiteness are paraunitary; a parameterization of such filters with plane rotations is proposed. Theoretical developments then lead to a numerical algorithm that sweeps all pairs of delayed outputs. This algorithm involves the solution of a polynomial system in two unknowns, whose coefficients depend on the output cumulants. Simulations and performance of the numerical algorithm are reported.