Fairness Optimization for VLC Systems With Liquid Crystal-Based RIS-Enabled Transmitters

The application of liquid crystal (LC)-based reconfigurable intelligent surface (RIS)-assisted transmitters in visible light communication (VLC) systems can guide and amplify the light emitted by light emitting diodes (LEDs). In this paper, we investigate the VLC system employing the RIS-assisted transmitter, where user fairness is maximized by optimizing the refractive index of the RIS module. To address the non-convex problem, we adopt the particle swarm optimization (PSO) algorithm. Simulation results illustrate that equipping the RIS-assisted transmitter in the system and using the proposed algorithm can significantly improve user fairness.