Estimation of rapid time-variant channels for OFDM using Wiener filtering

The performance of orthogonal frequency division multiplexing (OFDM) deteriorates in a rapidly time-varying environment due to the loss of orthogonality, resulting in inter-channel interference (ICI). Moreover, the quality of 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-aided 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.