RIS-aided Indoor Visible Light Communication System with Spatial Modulation

Visible light communication (VLC) is considered as a promising candidate for next-generation communication in scenarios such as the Internet of Things or indoor Internet broadcasting. However, VLC environments are often complex and varied, with inherent occlusion and blocking challenges. In this paper, we explore a reconfigurable intelligent surface (RIS)aided VLC system using spatial modulation (SM) to enhance communication in scenarios that the line-of-sight path is obstructed. We focus on optimizing the rotation angles of RIS units to improve the channel gain in different numbers of active transmitters using SM. Inspired by particle swarm optimization, a novel algorithm called the G-PSO algorithm is proposed. Simulations validate the superior bit error ratio performance at different signal-to-noise ratios and transmitter configurations of SM, evidencing significant systemic performance improvements.