A Spread-Spectrum System with Dual Processing Gains Designed for Cyclic Noise in Power Line Communications

摘要

We propose a spread-spectrum power line communication system considering the cyclic features of the noise in the lines. For this purpose, we model the noise as the sum of a time-invariant stationary process and two cyclostationary processes, i.e., cyclic continuous noise and cyclic impulsive noise. The proposed system employs two different countermeasures to each of these two classes of cyclic noise. For the cyclic continuous noise, it uses multiple-processing-gain spread spectrum technique: the smaller processing gains are assigned for the periods with lower instantaneous noise power and the larger ones for the periods of higher noise power. Considering the cyclic impulsive noise, convolutional coding with interleaving is applied. In order to analyze the performance improvement due to the employment of multiple processing gains, we introduce a simple model of the continuous noise. The overall performance is evaluated by computer simulation with the actual noise wave-form measured in power lines.