Progressive iterative channel estimation in fast time-varying OFDM systems

Considering the joint channel estimation and data detection in time-varying orthogonal frequency division multiplexing (OFDM) and addressing transmission performance degradation induced by the severe inter-carrier interference (ICI) at very high speed, a new progressive iterative channel estimation scheme is proposed. To alleviate the error propagation of the inaccurate data due to ICI, the measurement subcarriers in the Kalman filter is designed to be extended from pilots subcarriers to all the subcarriers progressively through the iterations. Furthermore, in iteration process, the interference of the non-pilot data to the measurement subcarriers is considered to be part of noise in the modified Kalman filter, which improves the estimation accuracy. Simulation indicates that the proposed scheme improves the performance in fast time-varying situation.