New Approach for Resolving Ambiguities for Semi-Blind Equalization of MIMO Frequency Selective Channels

This paper addresses the semi-blind equalization for a wireless multiple-input multiple-output (MIMO) system with frequency selective channels. When reformulating the convolutive blind signal separation problem to allow the application of ordinary complex independent component analysis (ICA), the number of permutations is increased. An algorithm presented here reduces the ambiguities to those of the non-frequency selective case and is applicable for channels with an arbitrary power delay profile. The remaining ambiguities can be solved by a short preamble. The efficiency of the proposed method is illustrated by numerical simulations. According to the bit error rate the semi-blind equalization shows a good performance in comparison to training based channel estimation & equalization