A new channel equalizer for OFDM-based wireless communications

Abstract

This paper presents a new channel equalizer for OFDM-based communication systems. The channel equalizer consists of the adaptive estimation of channel frequency response (CFR) and the signal recovery. CFR is obtained by the two-dimensional linear interpolation of pilots from the frequency axis and the time axis. To avoid the noise enhancement in signal recovery, maximum-likelihood sequence estimation (MLSE) is applied to improve 1.5dB in SNR while using Rayleigh fading channel model with 30Hz Doppler frequency shift. As compared to the linear equalizer without feedback, the division free approach provides more accurate signal recovery in circuit implementation.