A SLIPT-Based Hybrid VLC/RF Cooperative Communication System with Relay Selection

To ease the shortage of spectrum and energy encountered by internet-of-things (IoT), in this paper we investigate simultaneous lightwave information and power transfer (SLIPT) in a hybrid visible light communication (VLC)/radio frequency (RF) cooperative communication system. To facilitate the information delivery from an indoor VLC source (S) to a remote destination (D) located outdoors, a relay is selected from the multiple IoT devices that are randomly distributed within the coverage of S, thus dividing the entire transmission into two hops. In the 1st hop, the VLC signal received at the selected relay is divided into alternating current and direct current components for information decoding and energy harvesting, respectively. Then in the 2nd hop, the selected relay utilizes the harvested energy to forward the decoded source information to D through RF. Depending on the availability of channel state information, two relay transmission schemes are proposed, and the corresponding end-to-end outage probability is derived analytically by accounting for the different channel conditions across the two hops. Simulation results demonstrate the effects of the key parameters and the efficiency of the considered system.