A Low-Complexity Robust OFDM Receiver for Fast Fading Channels

Abstract

Orthogonal frequency division multiplexing (OFDM) receivers suffer significant performance degradation in time-varying fast fading channels because of the inter-carrier interference (ICI) induced by the Doppler effect. We previously proposed a novel iterative decision-directed channel estimation and ICI cancellation technique which can provide robust performance for mobile OFDM receivers moving at fast vehicle speed. The nutshell of the proposed technique is a channel estimator which is capable of estimating the ICI gains on each off-diagonal vector of the channel frequency response matrix of a doubly-selective fading channel, which corresponds to the ICI induced by the neighbor subcarrier symbol to current subcarrier. In this paper, we generalize the channel estimator and provide theoretical analysis on the achievable performance. As an application to digital video broadcasting terrestrial system, we provide intensive simulation results and detailed comparison on implementation complexity and performance with existing techniques to showcase the significance of the proposed technique in practical applications.