On the Impact of Mitigating Radiated Emissions on the Capacity of PLC Systems

An active technique to achieve reduction of emissions from PLC networks is presented based on intentional destructive interference by injection of an appropriately selected auxiliary signal into the otherwise unused ground-neutral circuit. Practical application hurdles are discussed. A strategy for the application of the technique in light of the discussed obstacles is presented. It is argued that, to lower implementation costs and due to the low number of impairing interference situations expected, the present active mitigation technique can be used only when a customer files a complaint or when the lowering of emissions is warranted to achieve higher transmission rates. A change based on a "measure at one point, mitigate everywhere" notion is proposed to facilitate the technical implementation of the technique and to lower installation costs. This modification allows a required antenna to be installed in the PLC modems themselves or at a very short distance to them. Simulation results show that the solution is viable. It is also shown that the use of mitigation techniques, even in the cases in which emission limits are not exceeded, can increase the overall Shannon capacity of the network by many tens of Mbps.