Iterative Blind Channel Estimation for OFDM Receivers

Finite-Alphabet based blind channel estimation in OFDM systems is known to be extremely complex due to an exhaustive search to be performed over a tremendous number of channel coefcient combinations. In this paper, we present a novel blind channel estimator, which dramat-ically reduces this number of coefcient combinations to be checked without a signicant deterioration in estimation quality. Hence, the new low complexity approach enables the application of blind channel estimators based on the -nite alphabet set even if the transmitted data are high-rate modulated. Furthermore, we show that the performance of blind channel estimation can be improved by an iterative process based upon the capabilities of channel coding. Us-ing bit error rates (BERs) before and after channel decod-ing, the algorithm is tested with simulations and compared to other blind and non-blind channel estimators.