Characterization of the cyclic short-time variation of indoor power-line channels response

Indoor power-line channels response exhibits a time-varying behaviour with a twofold nature. The first one is the well-known long-term variation caused by the connection and disconnection of electrical devices. The second one is a short-time variation, synchronous to the mains, whose origin is the dependence of the impedance presented by electrical devices on the mains voltage (Canete, FJ et al., 2005). The purpose of this paper is to assess the importance of this latter aspect in actual channels. To this end, a measurement procedure able to extract these short-time variations is described at first. Afterwards, a statistical analysis of the results obtained from a measurement campaign performed at different scenarios is given. Specifically, the delay spread, the peak excursion and the rate of change of the frequency response in the band from 1 MHz to 20 MHz are presented and discussed.