Study on fractal characteristics of low-voltage power line communication channel

Using the low voltage power line network as a medium for signal communication, data transmission and information exchange offers a convenient and inexpensive solution for modern communication system. With its violent time-varying, strong interference and severe attenuation, the analyses of this communication channel become a challenging but important basic subjects for the sustainable development of L-PLC (Low-Voltage Power Line Communication) technology. In this paper, we point to bring fractal theory in the study of the characteristics of L-PLC channel. Firstly, the time series measured from L-PLC network are analyzed by R/S method which provides us a quantitative analysis of long-term time-dependence of the time series. Then, the changing curves of power spectrum and statistical moment of these time series are drawn, for the analyzing of multi-fractal characteristics of this channel. The results has showed: Hurst index of measured time series are greater than 0.5, fractal dimension is greater than 1.0, L-PLC channel has obvious fractal and chaotic characteristics; statistical moment is a nonlinear function, multi-fractal spectrum is strict symmetrical, the L-PLC channel has strong multi-fractal properties.