Characterization of Noise in Narrowband Power Line Communications

During the last decades, the usage of telecommunications systems has increased rapidly. As a result of this increase, there is a need for the development of new telecommunications networks and transmission technologies. One of the currently considered technologies is electric power lines. The obvious advantage of using electric power lines as the data transmission medium is that every building and home is already equipped with the power line and connected to the power grid. The power line communication (PLC) systems use the existing alternating current (AC) electrical wiring as the network medium to provide high-speed network access points almost anywhere there is an outlet. However, power supply networks are not designed for communications and they do not present a favourable transmission medium. Thus, the PLC transmission channel is characterized by a large and frequency-dependent attenuation, changing impedance and fading as well as unfavourable noise conditions. Various noise sources, acting from the supply network, due to different electric devices connected to the network, and from the network environment, negatively influence a PLC system, causing disturbances in an error-free data transmission. This paper investigates and classifies the noise on a PLC network and proposes a noise model for various classes of noise superimposed on the PLC channel. The study output shows that the synchronous and asynchronous impulsive noise are the most disturbing forms of noise affecting the PLC channel. In addition, the result of the study also shows that the effect of coloured background noise is more felt in the low frequency zones