Fuzzy equalized integrated system of visible free space optic (VFSO) and BPLC

A new integrated system of visible free space optic (VFSO) and broadband powerline communication (BPLC) that applies the concepts of fuzzy logic for channel equalization is proposed. Having used already installed powerline cables and white LEDs as a communication channel this system has the advantage of low cost and easy implementation for data transmission. In this system the created intersymbol interference (ISI) due to nonlinear distortions over the equivalent channel of VFSO and PLC is a considerable issue hindering further increase in the attainable data rate. In this work, the equivalent channel model for integrated system is developed and in order to mitigate the influences of high power impulsive noises and multipath distortion of BPLC channel, which are the main causes of ISI, besides channel coding and choosing discrete multitone (DMT) as a robust modulation schemes in case of ISI we designed adaptive fuzzy equalizer system. Then the performance of fuzzy equalized integrated system was compared by decision feedback (DF) equalized system in case of steady state BER and convergence speed of channel equalization. The attained results have shown that by incorporating appropriate linguistic rules which can be derived from training symbols the system performance would be improved.