Joint power allocation for the multi-user NOMA-Downlink in a power-line-fed VLC network

Visible light communications (VLC) constitute as a promising downlink technique of supporting the ever-increasing tele-traffic. Since the ubiquitous mains power line constitutes a natural backbone feed for VLC, a combined power line and VLC network is conceived, where the source data are fed by power line communications (PLC) into the VLC network. We refer to it as a PLC-VLC network, where the power line connects the light emitting diodes without requiring a duplicated filter-backbone. Then, the information is forwarded to multiple users via visible light. Furthermore, to increase the downlink bit rate, non-orthogonal multiple access (NOMA) is invoked in VLC. For the sake of maximizing the sum-throughput, we conceive a joint PLC-VLC power allocation (JPA) strategy, where the power allocated both to the PLC and to the VLC links is jointly determined upon analyzing the power relationship between them. Our simulations demonstrate that NOMA significantly outperforms orthogonal multiple access (OMA) with the aid of the proposed JPA.