Complex Exponential Basis Expansion Model(CE-BEM) has the advantage of simple computation,independence on channel statistics and so on,it is used to time varying of channel estimation widely.But Gibbs effect produces unignored model error of CE-BEM.The paper analyzes the model error and the impact of baseline tilting method, then presents an channel estimator which mitigates the model error, the method estimate the slope of block period,then derives the new data model combined with the baseline tilting method and the LS algorithm and LMMSE algorithm.Computer simulation show that suggested method decreases MSE of critical-sampled CE-BEM and over-sampled CE-BEM in case of higher Doppler frequency shift extension, especially for the critical-sampled CE-BEM,performance is improved considerably.%复指数基扩展模型(CE-BEM)具有计算简单、不依赖于信道统计特征等优点,广泛地应用于时变信道估计中.但是CE-BEM由于Gibbs效应存在较大模型误差,本文分析了CE-BEM的模型误差以及基线倾斜法对模型误差的影响,提出了一种抑制模型误差的信道估计方法,该方法利用时分复用导频的特征估计出区间上的斜率,再结合基线倾斜法推导了新的数据模型,并给出LS算法和LMMSE算法.最后通过计算机仿真研究表明:该方法在较高的多普勒频移扩展的情况下有效的降低了关键性采样CE-BEM和过采样CE-BEM信道估计的MSE值,特别是关键性采样CE-BEM改善明显.
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