General pilot-aided scheme for OFDM reception in fast varying channels

Abstract

In high mobility scenarios, the channel variation over an OFDM symbol period destroys subcarrier orthogonality, and results in intercarrier interference (ICI). Recently, a piece-wise linear model has been proposed to mitigate ICI by approximating the channel variation over an OFDM symbol by linear model. However, for high Doppler spread the channel over an OFDM symbol exhibit high order variation. In this paper, a generalized scheme is proposed, where the channel variation over an OFDM symbol is approximated by a general polynomial model. Simulation results show that, at a high Doppler spread, the proposed scheme can achieve a significant improvement in the BER of OFDM over the piece-wise estimator.