Low Complexity DFE for OFDM Systems over Time-varying Channels

Although orthogonal frequency division multiplexing (OFDM) is a promising communication scheme to achieve high data rate transmission in frequency-selective fading channels, it is sensitive to channels´ variations, which cause intercarrier interference (ICI) and result in performance degradation. In this paper, a low complexity decision feedback equalizer (DFE) to reduce the effects of channels´ variations is presented. The main feature is to use a small matrix of main channel information and recursive calculation of matrix inverse to significantly reduce the complexity, which makes it feasible for low cost OFDM consumer terminals. Theoretical analysis and simulation results are provided to validate its effectiveness.