New equalization approach for OFDM over dispersive and rapidly time varying channel

The paper proposes and analyses a new receiver structure to mitigate the effect of Doppler on the reception of OFDM signals. A discrete-frequency channel representation is developed for the link between the input of the transmit I-FFT and the output of the receive FFT. It is based on a Taylor expansion of the time variations of the received subcarrier amplitudes. The model realistically addresses the correlation of fading at neighboring subcarriers. We study a new type of receiver which estimates not only amplitudes but also derivatives of subcarriers amplitudes. An adaptive MMSE filter is proposed to cancel the intercarrier interference (ICI) resulting from Doppler. This results in a substantial improvement of the link performance.