对于减少基于残留边带调制（VSB）的数字电视（DTV）接收机的符号间干扰（ISI），尽管判决反馈均衡器（DFE）是一种非常有效的方案，但这种方案由于受误差传播的影响而降低了接收质量。为减少误差传播，提出了一种使用软判决的DFE算法。该优化算法在判决器中使用了双曲正切函数，以改善DFE对抗误差传播的能力。此外，为了加快误差传播的仿真过程，还对反馈部分的抽头权值更新过程做了一个简单而有效的修改。计算机仿真结果表明，新算法对抗误差传播的性能远优于疑符算法，与理想DFE具有近似的表现。

Decision feedback equalizer(DFE) is an efficient scheme for suppressing intersymbol interference(ISI) in vestigial sideband(VSB) based digital TV(DTV) receivers.However,it suffers from error propagation(EP).This paper considers the use of soft decisions in mitigating EP in a DFE.An optimized soft decision algorithm using the hyperbolic tangent function in the decision device is proposed to improve performance over reducing EP.Furthermore,in order to speed up the EP simulation process,a simple but effective modification is made in the feedback tap weight updating process.Computer simulation results show that the proposed soft decision algorithm nearly meets the EP performance of ideal DFE,which is far better in performance compared to the erasure algorithm.