MLSD-type detection using a channel estimator for time-varying frequency-selective channels

Receiver structures for linearly modulated signals are proposed for frequency-selective fading channels. Their channel estimators explicitly model the time variation of the channel taps via polynomials. The channel is estimated by a sliding window or a fixed block channel estimation technique, and a maximum likelihood sequence detector (MLSD) type structure is employed for data detection. The receiver performs channel estimation and data detection in single or multiple passes. The bit error rate (BER) performance of the receivers is studied through simulation and analysis. In fast fading and high signal-to-noise ratio (SNR), the proposed receivers significantly outperform the per-survivor processing (PSP)-based MLSD receivers which employ the least mean squares (LMS) algorithm for channel estimation