Secrecy Sum Rate Maximization for OIRS-Aided Visible Light Communications with Confidential Messages
For VLC system designers, this work addresses physical obstructions and internal eavesdropping, but the method is incremental as it applies existing optimization techniques to a new system model.
This paper maximizes secrecy sum-rate in OIRS-aided VLC systems under LoS blockages by jointly optimizing transmission precoder and OIRS unit assignment, achieving significant SSR gains with increasing OIRS units.
This paper investigates the secrecy sum-rate (SSR) performance of optical intelligent reflecting surface (OIRS)-assisted multi-user visible light communication (VLC) systems under line-of-sight (LoS) blockages. To mitigate physical obstructions and internal eavesdropping, a joint optimization problem is formulated to maximize the SSR through the co-design of the transmission precoder and OIRS units assignment. Due to the binary constraints and coupled variables, the problem is highly non-convex. To solve it efficiently, an alternating optimization (AO) framework integrating the concave-convex procedure (CCCP) and first-order Taylor approximations is developed. Simulation results demonstrate the convergence of the proposed algorithm and show that increasing the number of OIRS reflecting units yields significant SSR gains.