Blind spatio-temporal equalization and impulse response estimation for MIMO channels using a Godard cost function

Abstract

Equalization and estimation of the matrix impulse response function of multiple-input multiple-output (MIMO) digital communications channels in the absence of any training sequences is considered. An iterative, Godard (1980) cost-based approach is considered for spatio-temporal equalization and MIMO impulse response estimation. Stationary points of the cost function are investigated with particular attention to the case when finite-length equalizers exist. Sufficient conditions are derived under which all stable local minima correspond to desirable minima. The inputs are extracted and cancelled one by one. The matrix impulse response is then obtained by cross-correlating the extracted inputs with the observed outputs. Identifiability conditions are analyzed.