基于NOMA和用户协作的上行移动边缘计算卸载效率优化  

Offloading efficiency optimization for uplink mobile edge computing based on NOMA and user collaboration

作　　者：李洋 胡阳 罗先南 刘昕[3] 齐婷 LI Yang;HU Yang;LUO Xiannan;LIU Xin;QI Ting(State Grid Electric Power Research Institute,Nanjing 211106,China;Nanjing NARI Information&Communication Technology Co.,Ltd.,Nanjing 211106,China;Key Lab of Broadband Wireless Communication and Sensor Network Technology,Ministry of Education,Nanjing University of Posts and Telecommunications,Nanjing 210003,China)

机构地区：[1]国网电力科学研究院有限公司,江苏南京211106 [2]南京南瑞信息通信科技有限公司,江苏南京211106 [3]南京邮电大学宽带无线通信与传感网技术教育部重点实验室,江苏南京210003

出　　处：《南京邮电大学学报（自然科学版）》2024年第3期33-41,共9页Journal of Nanjing University of Posts and Telecommunications：Natural Science Edition

基　　金：国家电网有限公司总部管理科技项目(5700-202040380A-0-0-00);江苏省自然科学基金(BK20200759)资助项目。

摘　　要：为应对大规模计算的需求以及有限传输资源和信道衰落的制约,提出了非正交多址接入(Non-orthogonal Multiple Access,NOMA)和用户协作辅助的上行移动边缘计算(Mobile Edge Computing,MEC)卸载传输方法。用户通过NOMA将计算任务卸载到MEC服务器以提高频谱效率,通过近端用户协助远端用户卸载的方式,减小中断对计算卸载的影响。为实现卸载量与能耗的最佳折中,定义卸载效率为成功卸载数据量与用户消耗能量之比,建立了通过调节卸载时间和功率分配来最大化卸载效率的联合优化问题。为求解该问题,推导了用户的卸载中断概率的闭合表达式,并将该非凸问题转化为松弛问题后利用连续凸近似方法求解。分析了该系统的中断性能,仿真结果表明所提计算卸载方法相较于其他方案能取得更高的卸载效率。To meet the demand of large-scale computing tasks and the challenge of limited transmission resources and serious channel fading,we propose a non-orthogonal multiple access(NOMA)and user cooperation assisted uplink mobile edge computing(MEC)offloading scheme.In this scheme,the user offloads computing tasks to the MEC server through NOMA to improve spectrum efficiency,and the local user helps the remote user with offloading to reduce the impact of outages on computing offloading.To achieve the best tradeoff between unloading quantity and energy consumption,the offloading efficiency is defined as the ratio of the amount of successfully offloaded data to the energy consumed by users.A joint optimization problem is established to maximize the offloading efficiency by adjusting the offloading time and power allocation.To solve this problem,a closed-form expression of the outage probability of a pair of users is derived.Then,the nonconvex problem is transformed into a relaxed problem and solved by continuous convex approximation.The simulation analyzes the outage performance of the system,and the results demonstrate that the proposed method can achieve higher offloading efficiency compared with other schemes.

关 键 词：移动边缘计算 非正交多址接入 用户协作 计算卸载 

分 类 号：TN92[电子电信—通信与信息系统]