An Experimental Characterization of the PLC Noise at the Source

Power-line communications (PLC) are affected by severe noise. In the inhome scenario, the household appliances are the main sources of noise, when they are fed and running, as they inject noise in the frequencies where PLC operate. This paper presents a methodology for the characterization of the noise generated by devices connected to the power grid. The methodology is applied to study a number of household appliances. The study enables: a) identifying the most noisy devices from which PLC transceivers should be kept far away; b) characterizing the noise both in the time and the frequency domain; c) addressing the definition of noise limits from an electromagnetic-compatibility regulator perspective; and d) quantifying the amplitude of the impulsive noise that may damage the analog front end of the PLC transceiver. This paper addresses the noise during the normal operating conditions of the household appliances, and the noise generated during transients, that is, when the device is connected, disconnected, or switched on or off. In this respect, it is shown that transients may lead to noise spikes that exceed tens of volts.