A trial combing a mirror array-based RIS with a liquid crystal-based RIS in indoor visible light communications

Abstract

The research on reconfigurable intelligent surface (RIS)-aided visible light communication (VLC) has been widely investigated in recent years. However, traditional research on this area only concentrates on one kind of VLC RIS (such as a mirror-based RIS or a liquid crystal (LC)-based RIS), however, dismissing the combination of different kinds of VLC RISs. Consequently, in consideration of the huge potential of the combination for VLC RIS, this paper proposes a trial combing a mirror array-based RIS with a liquid crystal-based RIS in an indoor visible light communication system. The optimization problem is formulated with achievable data rate maximization as the objective function, and meanwhile, the parameters of the two types of RIS is regarded as the independent variables. As for the non-convexity of the proposed optimization problem, in order to determine the optimal configuration of parameters for the two types of RIS, the particle swarm optimization (PSO) algorithm is adopted. Finally, the PSO algorithm is demonstrated to be an effective method to solve the optimization problem in the simulation results, and meanwhile, the combination of a mirror array-based RIS and a liquid crystal-based RIS is able to enhance communication performance to a greater degree compared with the RIS-aided VLC system which employs only one type of VLC RIS.