Transmit Power Optimization for a Hybrid PLC/VLC/RF Communication System

The number of indoor smart devices is rapidly growing which requires ubiquitous wireless connectivity for data communications. The limited available radio frequency (RF) spectrum motivates finding alternate wireless solutions. Visible light communications (VLC) are a wireless technology which have shown a high potential to offer wireless data communications in both indoor and outdoor scenarios. Power-line communications (PLC) technology is employed in VLC networks for data transfer between VLC sources due to the ubiquity and the infrastructure availability of power-line networks. As a result, the hybrid wireline/wireless technology of PLC/VLC can be exploited in a complementary fashion to the existing indoor RF networks for improving wireless connectivity. In this paper, we investigate the power allocation problem of a hybrid system composed of a cascaded PLC/VLC link in parallel to an RF wireless link. We formulate and analyze the problem of minimizing the total transmission power consumption under a defined quality of service constraint. Our results show that the proposed hybrid system, under different realizations of PLC, VLC, and RF channel models, provides considerable performance improvement compared to conventional RF systems.