Channel and Admittance Dependence Analysis in PLC with Implications to Power Loading/Savings

This paper investigates the relationship between the channel frequency response and the line admittance in power line communication channels. Should a dependence exist, the channel frequency response could be inferred at the transmitter from line impedance measurements and this would enable power loading without requiring feedback from the receiver to the transmitter. Firstly, a physical study of the PLC channel to identify under what conditions a relationship exists is carried out. The analysis is then extended to measured channels. It is found that a strict relationship between the channel frequency response and the line admittance exists only in particular cases. However, there are some scenarios where the frequency response is related to the line admittance and therefore power loading algorithms can be derived by measuring the line admittance only. In fact, using an experimental data set, it is shown that admittance based power loading offers power savings w.r.t. conventional uniform power allocation.