Interference Cancellation for MIMO-OFDM Systems in the case of Insufficient Guard Interval Length

This paper proposes a new interference cancellation scheme for multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) systems in the presence of intersymbol interference (ISI). The proposed interference cancellation scheme uses the estimated channel coefficients and the channel state information (CSI) to reproduce the interference components, then iteratively cancel them from the received signals. The so-called remodulation technique is also included in this scheme to enhance the interference cancellation performance. To illustrate the proposed method, we assume that the MIMO-OFDM system does not use a guard interval (spectral efficiency factor eta = 1). Simulation results show that the performance of system in terms of the symbol error ratio (SER) is significantly improved by applying one iteration of the proposed canceller. After two iterations, the SER is slightly better than the results obtained if the guard interval (GI) length is sufficient (eta = 0.87).