On the basis of the study of the maximum- likelihood estimation technique which elimilates the intersymbol interference

this paper presents a near-maximum-likelihcod estimation scheme which is used in the voiceband serial data transmission system. The scheme employs predecision feedback to reduce the number of the effective components of channel states and the simplified Viterbi algorithm

thus reducing the amount of operation. Simulation analysis indicates that the error performance of this scheme is superior to that of the decision feedback equalizer with the square root Kalman algorithm.