A robust channel equalizer for OFDM TV receivers

In this paper we present and analyze a nonparametric channel equalizer based on the moving average estimator. Since the OFDM system can be considered as a set of parallel Gaussian channels with different frequency gain for each subcarrier, we apply the theory of sample mean to each subcarrier by averaging the consecutive data symbols. Assuming the channel attenuations and the transmitted data symbols are constant while taking averages, this effectively removes noise and we can obtain the data symbols distorted only by the multipath channel. The proposed method does not require any a priori knowledge about the channel statistics. Furthermore, it has the performance improvement over conventional schemes even for slowly time-varying channels. We evaluate the equalizer through simulation using a 16 QAM OFDM system.