A Decision-Aided Residual ISI Cancellation Algorithm for OFDM Systems

We present a novel decision-aided algorithm in this paper for orthogonal frequency division multiplexing (OFDM) systems to eliminate the residual intersymbol interference (ISI) introduced by the channel impulse response that exceeds the length of the guard interval. The algorithm uses decisions to estimate the residual ISI by fast Fourier transform (FFT) and inverse fast Fourier transform (IFFT) with a very low computational complexity. This method can be applied for non-sample spaced channel. Simulations for the application of the residual LSI cancellation algorithm to the wireless LAN system (WLAN) are performed. The simulation results show that the residual LSI cancellation algorithm presented in this paper provides good performance improvements on static fading LSI channels