A Low-Complexity Concatenated ICI Cancellation Scheme for High-Mobility OFDM Systems

In this paper, a novel low-complexity scheme is proposed for current OFDM systems to reduce inter-carrier interference (ICI) caused by time-varying channel. Under the assumption that channel delay spread is smaller than the guard interval period of an OFDM symbol, the suitably selected inter-symbol interference (ISI) free received signals are exploited through compensating the corresponding linear phases and taking the average in the frequency domain, and in consequence some ICI terms can be automatically cancelled. However, the performance of this self-ICI cancellation scheme is restricted by the inadequate ISI-free region in current OFDM systems. Therefore, a concatenated scheme, which consists of the self-ICI cancellation scheme and a residual ICI reconstruction scheme, is proposed to further improve the BER performance. The simulation results are provided to support that the ICI effect can be significantly removed by the proposed low-complexity concatenated scheme for current high-mobility OFDM systems.