Novel noise reduction algorithm for LS channel estimation in OFDM system with frequency selective channels

Based on the analysis of the effect of the channel estimation error on the performance of Orthogonal Frequency Division Multiplexing (OFDM) systems, a novel noise reduction algorithm for the LS channel estimation is presented for OFDM systems with virtual carriers in frequency-selective fading channels. In the method, the estimated channel vector by the LS algorithm is further processed by the Q matrix from QR decomposition of the part DFT matrix and the zero-forcing processing, and the accuracy of the processed channel estimation vector is highly improved. Simulation results show that the performance of the proposed method is much better than those of the available noise reduction methods for the LS channel estimation, and the MSE of the proposed method is about one fifth of that of the LS method.