Novel Techniques to minimize the Error Propagation of Decision Feedback Equalizer in 8VSB DTV System

This paper proposes novel techniques to minimize the error propagation caused by large precursors and postcursors in decision feedback equalizer (DFE) of 8VSB DTV system. We first minimize the effect of large precursors by selecting a reference tap (symbol timing of DFE) from the channel estimation. By locating the reference tap, i.e., decision delay, in a feedforward filter (FFF) based on the channel estimation and the amplitude of a reference tap, the effect caused by large postcursors is minimized. Additionally, the combined structure of the feedback filter (FBF) and Viterbi decoder is proposed to correct the past incorrect decision symbols as well as to reduce the decision error probability. Simulation results show that the proposed techniques can prevent effectively the error propagation, and also they can remove much longer precursors as compared to conventional methods