用基于导频的维纳滤波器对快变信道进行性能评估

Estimation of Rapid Time-Variant Channels for OFDM Using Wiener Filtering

OFDM信号在快变信道中传输时会导致其正交性的破坏,会产生信道间干扰(ICI)。传统的信道仿真模型在快变信道的仿真过程中效果会有明显的下降,通过基于导频的OFDM信号,运用维纳滤波器对数字电视广播(DVBT)系统信道在时变WSSUS模型下进行了性能仿真,同时也分析了在运用与信道不匹配模型情况下的维纳滤波器模型进行分析时所带来的问题。

The performance of Orthogonal Frequency Division Muhiplexing（OFDM） deteriorates in a rapidly time- variant environment due to the loss of orthogonality, resulting in Inter Channel Interference（ICI）. Moreover, the quality of a model - based channel estimation may degrade if the estimator has been designed for a time- invariant scenario. In this paper,we consider OFDM and pilot - sided channel estimation via Wiener filtering and derive the filter for a time - variant WSSUS model. In addition, the analysis allows to compute the performance loss for an improper estimation filter which suffers from the problem of model mismatch.