Combining adaptive smoothing and decision-directed channel estimation schemes for OFDM WLAN systems

In this paper, a new channel estimation method for OFDM WLAN systems is proposed. This proposal mainly consists of smoothing filtering and decision-directed tracking loop schemes, where the former is used to enhance performance at low SNR and the latter is exploited to enhance performance at high SNR respectively. Together with an adaptive channel management, better performance in terms of MSE and PER can be achieved. Simulation shows the proposed method (1) achieves better 9.0dB similar to 13.0dB gain in MSE than zero forcing criterion and better 2.0dB gain in MSE than conventional approaches in BPSK transmission, and (2) contributes 0.8dB similar to 2.0dB gain in SNR for 10% PER in different transmission modes.