Quasi-synchronous noise interference cancellation techniques applied in low voltage PLC

Low voltage power lines are attractive for communications in smart metering, but they are subject to many kinds of interferences. One important source of interference is the one which is synchronous with the power network frequency. This noise shares the mean periodicity with the mains, but it also usually has some sort of time drift or jitter that shifts the position and phase of the signal from period to period. This paper refers to this particular kind of noise, which this paper will label as “quasi-synchronous”. Several processing techniques have been used to cancel this component of a signal. The core of the algorithm is the predictor and its learning mechanism, which is able to provide a predicted version of the quasi-synchronous noise adjusted to the variations of the input phase, ready to perform the cancellation. The results of these cancelation technologies are described, applied to both, synthetic and real input signals, to demonstrate that quasi-periodic noise can be cancelled with affordable processing power consumption.