A new OFDM demodulation method to reduce influence of ISI due to longer delay than guard interval

We propose a new OFDM demodulation method in order to reduce the influence of the intersymbol interference (ISI) and improve the bit error performance in the presence of multipaths whose excess delays are longer than the guard interval (GI). The influence of the ISI is eliminated or reduced by a variable-length windowed reception, and then the ICI component is reduced by a multi-stage intercarrier interference (ICI) canceller. The simulation results show that the proposed method improves the system availability under more various multipath fading environments without changing the system parameters.