Power efficient downlink resource allocation for hybrid RF/VLC wireless networks

The growing energy consumption of communication systems raises economical and environmental concerns. Indoor visible light communication (VLC) systems are energy friendly as they exploit the illumination power of LED luminaries for data transmission. However, the VLC systems suffer from service disruptions due to the limited coverage of light. To alleviate this problem, hybrid RF/VLC architecture has been recently proposed for indoor networks where the RF networks can be exploited to resolve the limited VLC coverage. In this paper, we consider a network composed of multiple VLC access points and an RF access points. We develop resource allocation algorithms to maximize the system's power efficiency defined as the total system throughput per unit power. Simulations show that deploying VLC access points improves the power efficiency of the system and increases the minimum guaranteed rate per user. Simulations also show that higher power efficiency can be obtained using the same number of operating VLC access points by redistributing them more uniformly across the room.