A new Decision-Feedback Equalizer (DFE) is proposed to overcome Inter-Symbol Interference (ISI) faster in the communication system without the aid of training sequences. Unlike the conventional DFE, the feedforward filter component and the feedback filter component in the proposed DFE operate with Constant Modulus Algorithm (CMA) and Decision-Directed (DD) algorithm respectively. It makes full use of the advantages of the CMA's "eyeopened" ability and DD's faster convergence rate ability. Consequently the proposed DFE has the faster convergence rate than the conventional DFE which can improve the performance for the system. Simulations with underwater acoustic channels are presented and the simulation results are shown to prove the efficiency of the proposed DFE.
Keywords-decision-feedback equalizer; constant modulus algorithm; decision-directed algorithm; underwater acoustic channelI.