智能反射面辅助短包通信中时效与能效间的折衷  

Tradeoff between Age of Information and Energy Efficiency for Intelligent Reflecting Surface Assisted Short Packet Communications

作　　者：张洋译 管新荣 王权 邓诚 朱泽源 蔡跃明 ZHANG Yangyi;GUAN Xinrong;WANG Quan;DENG Cheng;ZHU Zeyuan;CAI Yueming(College of Communication Engineering,Army Engineering University of PLA,Nanjing 210007,China;Unit 32319 of PLA,Urumqi 830002,China;Unit 32579 of PLA,Guilin 541000,China)

机构地区：[1]陆军工程大学通信工程学院,南京210007 [2]中国人民解放军32319部队,乌鲁木齐830002 [3]中国人民解放军32579部队,桂林541000

出　　处：《电子与信息学报》2025年第2期315-323,共9页Journal of Electronics & Information Technology

基　　金：国家自然科学基金(62171461,62171464)。

摘　　要：在监控物联网中,一些感知设备需要在能耗受限条件下及时地将采集信息回传给接入节点(AP),信息年龄(AoI)和能量效率(EE)对系统都很重要。该文研究了多设备监控物联网中时效与能效之间的折衷问题,其中感知设备在智能反射面(IRS)辅助下通过短包传输监控信息给AP。为了避免多个感知设备占用同一资源块导致包的碰撞,该文提出了一个接入控制协议,并推导了平均AoI和EE的闭式表达式。在此基础上,引入了平均AoI和EE之比这个指标,通过优化传输功率来最小化平均AoI和EE之比,以折衷时效性能与能效性能。仿真结果验证了该文理论分析的正确性,并且表明所提协议能够实现更好的时效和能效性能。此外,所提算法能够有效找出最优的时效-能效折衷点。Objective:In monitoring Internet of Things(IoT)systems,it is essential for sensor devices to transmit collected data to the Access Point(AP)promptly.The timely transmission of information can be enhanced by increasing transmission power,as higher power levels tend to improve the reliability of data transfer.However,sensor devices typically have limited transmission power,and beyond a certain threshold,increases in power yield diminishing returns in terms of transmission timeliness.Therefore,effectively managing transmission power to balance timeliness and Energy Efficiency(EE)is crucial for sensor devices.This paper investigates the trade-off between the Age of Information(AoI)and EE in multi-device monitoring systems,where sensor devices communicate monitoring data to the AP using short packets with support from Intelligent Reflective Surface(IRS).To address packet collisions that occur when multiple devices access the same resource block,an access control protocol is developed,and closed-form expressions are derived for both the average AoI and EE.Based on these expressions,the average AoI-EE ratio is introduced as a metric that can be minimized to achieve an optimal balance between AoI and EE through transmission power optimization.Methods:Deriving the closed-form expression for the average AoI is challenging due to two factors.Firstly,obtaining the exact distribution of the composite channel gain is difficult.Secondly,in short-packet communications,the packet error rate expression involves a complementary cumulative distribution function with a complex structure,complicating the averaging process.However,the Moment Matching(MM)technique can approximate the probability distribution of the composite channel gain as a gamma distribution.To address the second challenge,a linear function is used to approximate the packet error rate,yielding an approximate expression for the average packet error rate.Additionally,to examine the relationship between the ratio of average AoI and EE with transmission power,the second

关 键 词：信息年龄 能量效率 短包通信 智能反射面 

分 类 号：TN926[电子电信—通信与信息系统]