Opportunistic Relaying in In-Home PLC Networks

We consider the use of a relay to provide capacity improvements and range extension for in-home power line communication networks. In particular, we focus on opportunistic relaying where the relay is exploited only if it provides improved capacity w.r.t. the use of direct transmission between the source and the destination. The relay applies a decode and forward scheme and the channel is shared in a time division multiple access mode. The performance is studied in statistically representative in-home power line communication (PLC) networks via the use of a statistical topology model together with the application of transmission line theory for the computation of the channel transfer function among network nodes. The statistical topology model allows determining the capacity improvements as a function of the relay position. Furthermore, we determine the optimal time slot duration for each considered relay configuration, as well as we propose the use of a globally optimal time slot duration that maximizes the average network capacity. The numerical results show that significant capacity improvement can be obtained via opportunistic relaying in in-home PLC networks. The gains are more significant for low SNR scenarios and for networks composed by sub-networks each connected to the main panel via a circuit breaker that introduces signal attenuation.