摘要
无线传感器与基站之间容易因障碍物阻挡,影响信息交付的及时性,传感器能量供应不足也会引起信息年龄(AoI)性能下降。构建一种基于智能反射面(IRS)辅助通信的无线供能传感器网络系统模型,提出一个联合优化能量发射矩阵、IRS相移和传感器调度的多变量系统总信息年龄最小化优化问题。由于调度变量的二进制性质和IRS相移约束的非凸性质,导致该优化问题无法被直接求解,因此利用变量松弛和半正定凸松弛方法将原非凸问题转化为凸问题,并设计一种基于半正定凸松弛的信息年龄调度优化算法。实验结果表明,当能量站最大发射功率为45 dBm及IRS反射单元数为30时,所提算法相比循环调度算法、非能量收集算法,能将系统总AoI最大分别降低38%、46%,不仅可以为无线传感器持续供能,而且能提高系统的AoI性能。
To solve the problems that information freshness is easily affected by obstacles between the wireless sensor and Base Station(BS)and that insufficient energy supply of the sensor will lead to degradation of the Age of Information(AoI)performance,a wireless powered sensor network system model based on Intelligent Reflecting Surface(IRS)-assisted communication is proposed.First,an optimization problem of minimizing the sum AoI of multivariable systems is established by jointly optimizing energy emission matrix,IRS phase-shift,and sensor scheduling.Second,because of the binary characteristic of scheduling variables and the nonconvexity of IRS phase-shift constraints,the optimization problem cannot be solved directly.Thus,the original non-convex problem is transformed into a convex problem using variable relaxation and semi-definite convex relaxation,and an AoI scheduling optimization algorithm based on semi-definite convex relaxation is proposed.The experimental results show that when the maximum transmission power of the energy station is 45 dBm and the number of IRS reflection units is 30,the proposed algorithm can reduce the total AoI of the system by a maximum of 38%and 46%compared to the cycle scheduling and non-energy harvesting algorithms,respectively.It can not only continuously power wireless sensors but also improve the AoI performance of the system.
作者
杨荐焜
王茜竹
冉泳屹
陈丰
YANG Jiankun;WANG Qianzhu;RAN Yongyi;CHEN Feng(School of Communication and Information Engineering,Chongqing University of Posts and Telecommunications,Chongqing 400065,China;Institute of Electronic Information and Network Engineering,Chongqing University of Posts and Telecommunications,Chongqing 400065,China)
出处
《计算机工程》
CAS
CSCD
北大核心
2023年第8期146-153,162,共9页
Computer Engineering
基金
国家自然科学基金(62003067)
重庆市自然科学基金(cstc2021jcyj-msxmX0586)。
关键词
信息年龄
无线供能传感器网络
能量收集
智能反射面
传感器调度
Age of Information(AoI)
wireless powered sensor network
Energy Harvesting(EH)
Intelligent Reflecting Surface(IRS)
sensor scheduling
