Estimation of time-varying channels for pilot-assisted OFDM systems  

作　　者：TANG Tian DENG Gang JIANG Jun 

机构地区：[1]School of Engineering, Beijing University of Posts and Telecommunications, Beijing 100876, China

出　　处：《The Journal of China Universities of Posts and Telecommunications》2007年第2期94-98,共5页中国邮电高校学报（英文版）

摘　　要：Orthogonal frequency division multiplexing （OFDM） systems encounter performance degradations because of the time-varying （TV） channels common in wireless environments. The channel variations within one OFDM symbol introduce intercarrier interference. In this case, the frequency domain channel matrix is no longer diagonal, hence the corresponding channel estimation is challenging. In this article, two novel TV channel estimation approaches are proposed for the pilot-assisted OFDM systems, where the channel is approximated by the high-order linear model or the piece-wise linear model in time domain. The least square estimation is derived for the two kinds of channel approximations. The simulation is performed based on realistic TV channels with a fairly high Doppler spread. The results show the significant decreasing of the estimation mean square error using the proposed approaches.Orthogonal frequency division multiplexing （OFDM） systems encounter performance degradations because of the time-varying （TV） channels common in wireless environments. The channel variations within one OFDM symbol introduce intercarrier interference. In this case, the frequency domain channel matrix is no longer diagonal, hence the corresponding channel estimation is challenging. In this article, two novel TV channel estimation approaches are proposed for the pilot-assisted OFDM systems, where the channel is approximated by the high-order linear model or the piece-wise linear model in time domain. The least square estimation is derived for the two kinds of channel approximations. The simulation is performed based on realistic TV channels with a fairly high Doppler spread. The results show the significant decreasing of the estimation mean square error using the proposed approaches.

关 键 词：OFDM pilot-assisted modulation TV channels channel estimation 

分 类 号：TN929.05[电子电信—通信与信息系统]