Optimized Decision Feedback Equalizer and Comparison with MLSE Algorithm for GSM Channel

In this paper, we present basic equation of efficient recursive least square algorithm based on GMSK modulation by linear superposition of amplitude modulated pulses for reduction complexity in equalizer. In this here, the DFE method be improved using of signal processing technique and soft decision which is called ´´generalized DFE or GDFE method´´. We compare the performance and complexity GDFE with MLSE method for different channels used in GSM systems. The GDFE differs from the conventional DFE in its tap values and value of tap feedback filter related with channel length, which discussed in simulation result. Our simulation results, obtained for fading multi path channels, show that the GDFE scheme improves the performance 1 dB approximately in comparison with conventional DFE. The GDFE method is robust to errors channel and this is a good specific beside low complexity, which is applicable in practical systems.