Optimization on Multi-User Physical Layer Security of Intelligent Reflecting Surface-Aided VLC

TL;DR

This paper explores enhancing physical layer security in multi-user VLC systems using intelligent reflecting surfaces, proposing an optimization algorithm that improves secrecy rates with verified simulation results.

Contribution

It introduces a novel system model for IRS-aided VLC with multiple users, transforming the secrecy rate maximization into an assignment problem and proposing an efficient iterative optimization algorithm.

Findings

The proposed algorithm effectively maximizes secrecy rate.

Numerical results confirm IRS improves VLC security.

The method has manageable computational complexity.

Abstract

This letter investigates physical layer security in intelligent reflecting surface (IRS)-aided visible light communication (VLC). Under the point source assumption, we first elaborate the system model in the scenario with multiple legitimate users and one eavesdropper, where the secrecy rate maximization problem is transformed into an assignment problem by objective function approximation. Then, an iterative Kuhn-Munkres algorithm is proposed to optimize the transformed problem, and its computational complexity is in the second-order form of the numbers of IRS units and transmitters. Moreover, numerical simulations are carried out to verify the approximation performance and the VLC secrecy rate improvement by IRS.