Semi-Blind Time Domain Equalization for MIMO-OFDM Systems

In this paper, a semi-blind time domain equalization technique is proposed for general MIMO-OFDM systems. The received OFDM symbols are shifted by more than or equal to the cyclic prefix length and a blind equalizer is designed to completely suppress both inter-carrier interference (ICI) and inter-symbol interference (ISI) using second-order statistics of the shifted received OFDM symbols. Only a one-tap equalizer is needed to detect the time domain signals from the blind equalizer output with the aid of one pilot OFDM symbol. The technique is applicable irrespective of whether the cyclic prefix length is longer than, equal to, or shorter than the channel length. Computer simulations show that the proposed technique outperforms the existing ones and it is robust against the number of shifts in excess of the cyclic prefix length