Decision-directed channel estimation method for OFDM systems with high velocities

The preamble-based channel estimation schemes typically applied in both the HIPERLAN/2 and IEEE 802.11a systems cannot fulfill the requirements in scenarios with high velocities. Therefore, this paper deals with the decision-directed estimation (DDE) method for a blind channel estimation procedure. With the help of the output decision symbols from the demodulator at the receiver side, the statistical characteristics of the transmitted data via the noisy fading channel are applied for tracking the fast changing channel transfer function. As a result, DDE can improve the performance of OFDM systems in high velocity applications with a very low computation complexity.