MIMO-OFDM Systems with Imperfect Channel Information: Capacity, Outage and BER Performance

In this paper, a study of the effect of channel estimation error on the capacity, outage probability, and bit error rate (BER) performance of multiple-input multiple-output OFDM (MIMO-OFDM) systems, is provided. First, a lower bound for the mutual information of MIMO-OFDM in the presence of channel estimation error is derived. Then, we derive an outage probability expression under imperfect channel information for MIMO-OFDM systems in general and for space-frequency block coded OFDM (SFBC-OFDM) in particular. Furthermore, we consider SFBC-OFDM used in conjunction with adaptive modulation, and evaluate the spectral efficiency of the adaptive SFBC-OFDM system under imperfect channel information at the transmitter. Simulation results are provided to analyze the performance of the MIMO-OFDM systems under study, and quantify the amount of degradation that imperfect channel information yields on the channel capacity, BER, outage probability and system throughput.