Power savings with opportunistic decode and forward over in-home PLC networks

We consider a cooperative system to provide power saving, quality of service, and coverage extension over in-home power line communications (PLC) networks. We focus on a cooperative relay scheme, where the communication between source and destination nodes follows an opportunistic time division decode and forward (ODF) protocol. At the physical layer we assume the use of a multi-carrier scheme. We show that the joint problem of power and time slot allocation for the multi-carrier time division decode and forward (DF) protocol is not convex. To reduce the complexity, we propose an heuristic algorithm that considers two convex sub-problems. The validation of the algorithm is done over statistically representative in-home PLC networks. Through extensive numerical results, we show that the use of relaying allows for saving several dBs of transmitted power, yet achieving the same rate of the direct transmission. Furthermore, over multiple sub-topologies networks interconnected through circuit breakers, e.g., a multi-floor house, the relay increases the network coverage.