OFDM Channel Estimation Algorithm Research and Simulation in Tunnel Environment

摘要

Least square (LS) algorithm based on least square criterion has poor estimation performance under low signal to noise ratio, if we directly use this method in tunnel environment, it will lead to larger estimation error. Considering the defects of the LS algorithm, this paper propose an improved LS channel estimation algorithm based on DFT time domain filtering. Firstly, this method will remove noises outside the guard interval; then, by setting a dynamic threshold, noises within the guard interval will be removed. Simulation results show that this method can achieve better estimation performance in low signal-to-noise ratio by selecting appropriate threshold, and this method is suitable for channel estimation in tunnel.