An equalization technique for OFDM and MC-CDMA in a time-varying multipath fading channels

In this paper, an equalization technique for OFDM and MC-CDMA systems in a time-varying multipath fading environment is described. A loss of subchannel orthogonality due to time-variation of multipath channels leads to interchannel interference (ICI) which increases the error floor in proportion to Doppler frequency. A simple frequency domain equalizer which can compensate the effect of time-variation in a multipath fading channel is proposed by taking into account only the ICI terms significantly affecting the error performance and by modifying the previous frequency-domain equalization techniques. The effectiveness of the proposed approach is demonstrated via computer simulation by applying it to OFDM system when the multipath fading channel is time-varying.