Optimal Soft Slicer Design for MMSE-DFE

A technique on optimal decision feedback equalizer (DFE) soft feedback slicer design is proposed in this letter. A soft slicer of M-ary PAM is given as a function of the noise variance at the slicer input. The equalizer mean-square error (MSE), which includes the error propagation effect, is used as the criterion of the optimal soft slicer design. By incorporating the slicer characteristics into the MSE and the assumption of Gaussian noise distribution at the equalizer output, the optimal soft slicer is obtained by minimizing the MSE. Simulation results corroborate the effectiveness of the method.