Piece-Wise Polynomial Approximation Based Channel Estimation for High-Mobility OFDM

In this paper, we deal with channel estimation and intercarrier interference mitigation for very high mobility OFDM systems, the communication is between a BS and a train traveling at a speed of 500 km/hr. The scheme proposed here uses piece-wise polynomial expansion to approximate time-variations of multipath channels. Two adjacent symbols are utilized to estimate the first and second-order parameters. In order to improve the estimation accuracy and mitigate the intercarrier interference caused by pilot-aided channel estimation, the multipath channel parameters were re-estimated in time-domain employing the tentative decision of current OFDM symbol. Simulation results show that this method would improve estimation accuracy and system performance in a high-mobility environment.