A subband adaptive blind equalization for MIMO system

A subband adaptive equalization technique based on normalized least square(NLMS) algorithm is proposed for the multiple-input multiple-output (MIMO) systems under the blind environments. For subband equalization, all the adaptive filters are decomposed to polyphase components, and the coefficients of the decomposed adaptive subfilters are updated by defining the multiple cost functions. The effect of prewhitening to the data through the subband filtering can speed up the convergence rate without additional computation. The improved performances of the proposed algorithm to the convergence rate and constellation equalization are validated by simulations.