A predictor-based decision feedback channel estimation method for COFDM with high resilience to rapid time-variations

This paper investigates the performance of a coherent COFDM system in the presence of a time-varying frequency-selective fading channel using a predictor-based channel estimator. The channel estimation method is based on a decision-directed adaptive technique that uses decisions at the output of either the detector (uncoded mode) or the decoder (coded mode). The main aim is to investigate the effect of using a time-domain predictor on the performance of the channel estimator and to compare its impact on both the coded and uncoded estimator modes. It is found that the predictor significantly improves the estimator´s performance, especially when the channel changes rapidly between consecutive OFDM symbols. It is also found that the performance of both the coded and uncoded estimator modes converge for SNR>15 dB