Simultaneous lightwave information and power transfer: Policies, techniques, and future directions

Harvesting energy from the surrounding environment is an important and practical solution to prolong the life of the energy-constrained Internet-of-Things (IoT) devices, e.g., wireless sensors. Visible light communications (VLC) has been proved able to provide high-speed data links while meeting the illumination requirement. Thereby, the energy of VLC signals may be harvested by the energy-constrained IoT terminals, such as indoor sensors and portable/wearable devices. This paper presents the concept of simultaneous lightwave information and power transfer (SLIPT) with a particular focus on the design of the receiver and the practical methods to realize SLIPT in the domains of time, signal components, and photoelectric converters. Furthermore, this paper also introduces the applications of SLIPT to various network topologies and communication technologies, e.g., multiple input multiple output, hybrid VLC-radio frequency, and secure communications. Finally, a detailed discussion of future research directions and challenges for the design of SLIPT systems is also presented.