Turbo equalization for OFDM with time-varying channels by new modified Kalman filter

Time-varying channels lead to the loss of orthogonality among sub-carriers, resulting in inter-carrier interference (ICI) in OFDM systems. To compensate for this ICI, we give a turbo equalization based on new Kalman filter for OFDM with time-varying channels. This algorithm uses soft mapping and soft de-mapping to realize information exchange via turbo iteration, realizes the update of channel response, and mitigates the ICI partly. Theoretical analysis and simulation results indicate that the method in this paper can effectively track channel and mitigate ICI. It has good BER performance even the channels are fast varying.