Energy-efficient subchannel assignment and power allocation in VLC-IoT systems with SLIPT

Abstract

In this paper, we investigate joint subchannel assignment and power allocation for the energy efficiency (EE) optimization in an indoor visible light communication (VLC)-Internet of Things (IoT) system with simultaneous lightwave information and power transfer (SLIPT). A mixed-integer fractional nonlinear programming problem that is challenging to solve is formulated. To tackle this problem, the optimal transmission scheme is decomposed into subchannel assignment and power allocation. Firstly, a virtual cell formation and subchannel assignment (VCF-SA) scheme is proposed, which considers the location of IoT devices, quality of service requirements, and energy states. Secondly, a quadratic transformation-based power allocation (QTBPA) scheme is designed to transform the fractional nonlinear programming problem into a series of convex problems that can be solved iteratively. Simulation results illustrate the effectiveness of the proposed scheme in terms of system EE compared to the benchmarks. The impact of system parameters on the EE is also analyzed.