摘要
空中智能反射面(Intelligent Reflecting Surfaces,IRS)结合了空中平台与IRS的优势,具有灵活调控无线信道的能力。在移动边缘计算(Mobile Edge Computing,MEC)系统中,物联网设备通过无线通信方式卸载计算任务。由于障碍物阻挡导致的信道衰减和无线信道的广播特性,MEC系统面临卸载速率受限和计算任务信息泄露的风险。本文提出利用空中IRS辅助MEC系统的任务安全卸载,以解决上述问题。在该系统中,物联网设备在分配的时隙内将计算任务卸载到MEC服务器进行计算,空中IRS通过动态调整反射相移和位置,为任务卸载创建安全的信道条件。本文提出一种系统资源联合优化策略,在能量和计算需求约束下,综合优化IRS相移、时隙分配、计算频率、发射功率和IRS位置,以最大化物联网设备的最小安全计算速率。为解决该非凸优化问题,本文采用块坐标下降法分解原问题,并结合半正定松弛法和连续凸逼近法,将非凸问题转化为可解的凸问题。仿真结果表明,本文所提方案能有效提升MEC系统的安全计算能力。
Aerial Intelligent Reflecting Surfaces(IRS)by combining the advantages of aerial platforms and IRS,have the ability to flexibly control wireless channels.In mobile edge computing(MEC)systems,Internet of Things(IoT)devices offload computational tasks via wireless communication.Due to channel attenuation caused by obstacles and the broadcast nature of wireless channels,MEC systems face the risks of limited offloading rates and information leakage.A secure task offloading scheme is proposed for MEC systems assisted by aerial IRS to address these issues.In this system,IoT devices offloaded computational tasks to the MEC server within allocated time slots,while an eavesdropper attempted to intercept the information.The aerial IRS dynamically adjusted its reflection phase shifts and position to create secure channel conditions for task offloading.A joint optimization strategy was developed to optimize IRS phase shifts,time slot allocation,computation frequency,transmit power,and IRS position under energy and computation constraints.The original non-convex problem was decomposed using the block coordinate descent method,and a combination of the semidefinite relaxation and successive convex approximation methods was applied to convert it into a solvable convex problem.Simulation results show that the proposed scheme effectively improves the secure computation capability of the system.
作者
陈智文
崔苗
张广驰
Chen Zhiwen;Cui Miao;Zhang Guangchi(School of Information Engineering,Guangdong University of Technology,Guangzhou 510006,China)
出处
《广东工业大学学报》
2025年第3期111-122,共12页
Journal of Guangdong University of Technology
基金
广东省基础与应用基础研究基金资助项目(2023A1515011980,2023A1515140003)
广东省科技计划项目(2022A0505050023,2023A0505050127)
江西省军民融合研究院“北斗+”项目子课题资助项目(2024JXRH0Y02)。
关键词
空中智能反射面
移动边缘计算
安全卸载
智能反射面位置
aerial IRS(Intelligent Reflecting Surfaces)
mobile edge computing(MEC)
secure offloading
IRS position
