Two-step channel estimation scheme for OFDM systems over fast Rayleigh fading channels

This paper proposes a two step pilot-based channel estimation scheme for orthogonal frequency-division multiplexing (OFDM) systems over fast Rayleigh fading channels. In the proposed scheme, the detected symbol from the first step is propagated into the second step to improve the performance of estimator. Specifically, we introduce the adaptive threshold using a noise variance estimation with the different posterior probability to exclude the false detected symbols. The simulation results show that the proposed scheme is better compared to the conventional methods over fast Rayleigh fading channels.