Decision directed channel estimation method for scattered pilot OFDM signal in fast varying fading environments

摘要

This report studies applying scattered-pilot OFDM (Orthogonal Frequency Division Multiplexing) systems to mobile communications, and proposes a new channel estimation method that can track the fast varying fading channels properly. The proposed method is an extended version of the conventional RLS-based channel estimation into the decision directed one. Initially, at every sub-carrier, the method carries out temporal signal detection and updates the channel estimation by using the temporally detected signals. After an error correction process, it repeats the channel estimation by using the error-corrected detected signals. Computer simulations in accordance with the Digital Terrestrial Television Broadcasting (DTTB) standard demonstrate that coherent detection employing the proposed channel estimation is superior to differential detection in the tracking performance and can achieve an excellent BER performance.