Abstract: In orthogonal frequency division multiplexing systems，time-varying channels results in severe intercarrier interference，at the same time，random phase noise introduced by oscillator causes both the common phase error and the ICI，which degrade the OFDM system performance severely.A channel estimation algorithm is proposed based on fractional basis expansion model to join the time-varying channel and phase noise by using the spliced pilots and minimum mean square error.The simulation results indicate the algorithm can estimate the channel information accurately.

Key words: Orthogonal Frequency Division Multiplexing（OFDM）, channel estimation, phase noise

摘要： 在正交频分复用系统中，信道的时变特点导致严重的子载波间干扰，同时，由振荡器产生的相位噪声会带来公共相位错误和子载波间干扰，这都使OFDM系统的性能急剧恶化。基于分数倍基扩展模型，利用重叠导频和最小均方准则，对时变信道和相位噪声联合估计。仿真结果表明，所提出的算法可以提高信道估计质量。

关键词: 正交频分复用, 信道估计, 相位噪声