The effect of channel estimator memory mismatch on the performance of MLSE in wireless data communications

The maximum likelihood sequence estimator (MLSE) has been shown to be an effective measure against inter-symbol interference. An estimate of the discrete-time equivalent channel is usually required in order to perform sequence estimation. In practice, the length (or memory) of the channel is unknown to the receiver for wireless communication channels. In this paper, upper and lower bounds for the performance loss due to channel estimator memory mismatch are derived for unbiased estimators, while approximate expressions for the irreducible BER floor caused by channel estimator memory mismatch are derived for biased estimators. Simulation results are also provided for random channels to verify the correctness of the analysis.