Reduced complexity MLSD equalizers based on bidirectional DFEs

We propose a reduced complexity maximum likelihood sequence detection (MLSD) equalizer for wireless communications using bidirectional decision feedback equalizers (DFEs). We apply reducedlength two-level estimates produced by a bidirectional DFE. Therefore, the computationally expensive MLSD algorithm is applied sparingly for twolevel signals with the effective channel length shorter than the original channel, regardless of the original constellation size of the symbols. Simulation results show that the proposed algorithm outperforms existing combination schemes based on bidirectional DFEs, especially for large constellations.