An Extended Kalman Filter Based Decision Feedback Fuzzy Adaptive Equalizer For Power Line Channel

In this paper, based on fuzzy logic, adaptive equalization, feedforward and decision feedback approaches, we propose a new decision feedback fuzzy adaptive equalizer (fuzzy DFE) that using extended Kalman filter (EKF) adaptation algorithm to cope with the intersymbol interference (ISI) effects of power line communication channels and the impulsive noise generated by electrical appliances and nonlinear loads that connected to power grids. The simulation results show that the proposed fuzzy DFE technique applied to minimize both influences of the ISI and impulsive noise has lower steady state bit error rate and faster convergent speed compared to conventional decision feedback equalizer (DFE) that using least mean squares (LMS) adaptation algorithm. The proposed fuzzy DFE also performs better than fuzzy DFEs that using RLS and LMS adaptation algorithms in terms of steady state bit error rate and convergent speed when direct sequence spread spectrum is employed as a transmission technique. The bit error rate of the EKF based fuzzy DFE is close to that of the optimal equalizer.