标题： 基于RIS的可见光通信系统的最大最小安全速率和安全能效优化：RSMA对比NOMA 显示英文标题

标题： Max-Min Secrecy Rate and Secrecy Energy Efficiency Optimization for RIS-Aided VLC Systems: RSMA Versus NOMA

摘要： 将VLC与RIS集成显著增强了物理层安全性，通过实现精确的方向信号控制和对通信环境的动态适应。 这些能力加强了VLC系统的保密性和安全性。 本文研究了VLC接入点功率分配、RIS关联以及RIS元件导向角联合优化的安全VLC系统问题，同时考虑了RSMA和功率域NOMA方案。 具体而言，提出了两个框架以最大化最小安全速率（SR）和最小安全能量效率（SEE），通过联合优化功率分配、RIS关联以及功率域NOMA和基于RSMA的VLC系统的RIS元件导向角。 所提出的框架考虑了随机设备方向，并保证了最小用户速率需求。 所提出的优化框架属于混合整数非线性规划类，该类问题没有已知的可行解方法来保证最优解。 此外，由于功率控制、RIS关联和元件导向的联合考虑增加了自由度和灵活性，导致了一组较大的决策变量和约束条件，这进一步复杂化了优化问题。 为此，我们利用了一种基于遗传算法的求解方法，它通过其探索和利用能力可以获得高质量的解。 此外，全面的仿真表明，在各种网络参数下，RSMA方案在SR和SEE指标上均优于功率域NOMA方案。 此外，还提供了关于最小用户速率要求、RIS元件数量和最大VLC AP发射功率对最小SR和SEE性能影响的有用见解。 显示英文摘要

摘要： Integrating VLC with the RIS significantly enhances physical layer security by enabling precise directional signal control and dynamic adaptation to the communication environment. These capabilities strengthen the confidentiality and security of VLC systems. This paper presents a comprehensive study on the joint optimization of VLC AP power allocation, RIS association, and RIS elements orientation angles for secure VLC systems, while considering RSMA and power-domain NOMA schemes. Specifically, two frameworks are proposed to maximize both the minimum secrecy rate (SR) and the minimum secrecy energy efficiency (SEE) by jointly optimizing power allocation, RIS association, and RIS elements orientation angles for both power-domain NOMA and RSMA-based VLC systems. The proposed frameworks consider random device orientation and guarantee the minimum user-rate requirement. The proposed optimization frameworks belong to the class of mixed integer nonlinear programming, which has no known feasible solution methodology to guarantee the optimal solution. Moreover, the increased degree of freedom and flexibility from the joint consideration of power control, RIS association and element orientation results in a large set of decision variables and constraints, which further complicates the optimization problem. To that end, we utilize a genetic algorithm-based solution method, which through its exploration and exploitation capabilities can obtain a good quality solution. Additionally, comprehensive simulations show that the RSMA scheme outperforms the power-domain NOMA scheme across both the SR and SEE metrics over various network parameters. Furthermore, useful insights on the impact of minimum user rate requirement, number of RIS elements, and maximum VLC AP transmit power on the minimum SR and SEE performances are provided.