中文摘要：

因为，直角的频率部门 multiplexing (OFDM ) 系统遇到表演降级变化时间(电视) 在无线环境普通的频道。在一个 OFDM 符号以内的频道变化介绍 intercarrier 干扰。在这种情况中，频率领域频道矩阵不再是斜的，因此相应频道评价是挑战性的。在这篇文章，二条新奇电视频道评价途径为帮助飞行员的 OFDM 系统被建议，在频道被高顺序的线性模型或片明智的线性模型及时接近的地方域。最少的方形的评价为二种频道近似被导出。模拟与相当高的 Doppler 传播基于现实主义的电视频道被执行。结果显示出用建议途径的评价均方差的重要减少。

英文摘要：

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.