Iterative hybrid decision-aided equalization for wireless communications

This paper presents a new method for combating error propagation in a decision-feedback equalizer (DFE) referred to as the hybrid decision-aided equalizer. Simulation results show that the performance of the hybrid decision-aided equalizer is significantly (1.5-2 dB) better than the DFE, and is in fact close to that of the maximum likelihood sequence estimator (MLSE). Detailed complexity analysis shows that the complexity of the hybrid decision-aided equalizer is significantly lower than that of the MLSE. An iterative version of the hybrid decision-aided equalizer is also presented in this paper in which effective stopping rules are implemented. It is shown that a significant additional gain in performance (1 to 2 dB) is achieved with a moderate increase in complexity.