Capacity Bound and Ber Performance of Ofdm System in High-mobility Scenarios

In this paper, we investigate the effect of velocity and channel information on the capacity of orthogonal frequency division multiplexing (OFDM) system in very rapidly time-varying fading channels. Lower bounds on the capacity of OFDM system in fast time-varying channels with perfect and imperfect channel state information (CSI) are derived. Simulation results show two main conclusions. One is that the capacity bounds change very little with increasing velocity in the channel with perfect CSI. Another is that the transmission performance is decreased quickly by the increased channel estimation errors due to high mobilities in the channel with imperfect CSI. Furthermore, we adopt block Markov superposition transmission (BMST) code to verify the conclusions.