Joint Turbo Equalization and Channel Estimation with Fixed-Lag Extended Kalman Filtering

In this paper, we present a low complexity turbo equalization receiver for data transmission over time-varying frequency-selective fading channels. In the receiver, a fixed-lag Kalman equalizer jointly estimates the channel and equalizes the data symbols with the assistance of a priori information supplied by the decoder. The complexity of the proposed equalizer does not grow exponentially with the modulation constellation size, and is usually lower than that of many maximum a posteriori equalizers performing joint channel estimation and detection. Performance comparison with different types of turbo equalizers demonstrates the advantage of the proposed turbo equalizer.