Blind signal separation and equalization with controlled delay for MIMO convolutive systems

In this paper we consider the problem of blind source separation and equalization of multiple-input multiple-output (MIMO) convolutive systems. We propose a new approach allowing the recovery of all source signals with a desired delay. It is made up of the constant modulus (CM) and an appropriate second order terms. The study of the stationary points of the criterion reveals that the only existing minima correspond, in the absence of noise, to a perfect recovery of all transmitted signals with the desired delay. Therefore, with this criterion we are able to control the separator delay, which allows, on the one hand, to remove the delay ambiguity inherent to blind equalization of MIMO convolutive systems, and on the other hand, to improve considerably the performance when the delay is chosen appropriately. Moreover, we propose two ways to implement the criterion, a batch implementation and an adaptive one. The effectiveness of the proposed approach is illustrated via several simulation experiments. (C) 2010 Elsevier B.V. All rights reserved.