Abstract: This paper first constructs the MIMO-OFDM system model over frequency- and time-selectivity fading channels. Then the connection between selective-fading diversity and capacity is analyzed, which shows that the product of the time-selectivity order and the frequency-selectivity order is the key parameter for characterizing the outage probability and outage capacity. An equivalent analysis method is proposed to give a tight low bound of ergodic capacity. It is also shown that this low bound becomes tighter with the increasing number of transmitter antennas. Finally numerical results of outage probability and outage capacity are shown by Monte Carlo simulation.

Key words: MIMO, OFDM, selective-fading, capacity