AI 中文总结
本文针对ARIS辅助高速列车通信系统的物理层安全问题，提出联合优化算法，提升了保密率，为高速列车通信安全覆盖增强提供了有效方案。
AI 中文摘要
高速列车（HST）已成为重要的交通方式，为其乘客提供高速率、可靠的通信服务是必要的。然而，高速列车通信系统中的无线信道易受包括窃听在内的各种安全威胁，因此解决这些安全问题至关重要。一种有前景的安全增强技术是将可重构智能表面（RIS）集成到无人机上，称为空天可重构智能表面（ARIS）。该技术在提升无线网络性能方面具有巨大潜力，但也给物理层安全（PLS）带来了独特挑战。本文研究ARIS辅助的高速列车通信系统的物理层安全，通过联合优化基站（BS）的有源波束成形和ARIS的相移，在基站发射功率约束和ARIS反射系数单位模约束下，构建加权和保密率最大化问题。为解决该问题，提出一种基于块坐标下降法的联合优化算法，具体将问题分解为有源波束成形设计和ARIS相移优化两个子问题：有源波束成形通过逐次凸近似技术优化设计，ARIS相移采用交替方向乘子法高效更新。仿真结果表明，所提算法收敛速度快，与现有文献中的方法相比，能实现更高的保密率。
英文摘要
High-speed trains (HSTs) have become a prominent means of transportation, requiring high data rates and reliable communication services for HST passengers. However, the wireless channels in HST communication systems are susceptible to various security threats, including eavesdropping. Addressing these security concerns is therefore of critical importance. One promising technology for enhancing security is the integration of a reconfigurable intelligent surface (RIS) on an unmanned aerial vehicle, referred to as an aerial reconfigurable intelligent surface (ARIS). This technology offers significant potential for improving wireless network performance, though it also introduces unique challenges in terms of physical layer security (PLS). This paper investigates the PLS of ARIS-aided HST communication systems. A problem of maximizing the weighted sum secrecy rate is formulated by jointly optimizing the active beamforming at the base station (BS) and the phase shift at the ARIS, subject to constrains on the BS transmit power and the unit modulus of the ARIS reflecting coefficient. To address this problem, a joint optimization algorithm is proposed using the block coordinate descent method. Specifically, the problem is decomposed into two subproblems: active beamforming design and ARIS phase shift optimization. The active beamforming is optimally designed via the successive convex approximation technique, while the ARIS phase shift is efficiently updated using the alternating direction method of multipliers technique. Simulation results demonstrate the rapid convergence of the proposed algorithm, which achieves a higher secrecy rate compared to existing methods in the literature.
CommentsAccepted by IEEE Transactions on Vehicular Technology
