认知物联网短包通信中双向中继系统的信息年龄分析

Age of Information for Short-Packet Two-Way Relay System in Cognitive IoT Network

未来认知物联网(IoT)将存在大量用于监控的时间敏感类短包信息。针对认知物联网短包通信场景,该文分析了认知次用户对在双向中继短包通信系统中的信息新鲜度。该文采用信息年龄(AoI)作为衡量信息新鲜度的性能指标。根据短包通信理论,该文推导出系统的误包率和平均峰值AoI(PAoI)表达式,并得出了系统在高信噪比情况下的表达式。在此基础上,考虑认知物联网短包通信中频谱检测性能的非理想,采用交替迭代优化算法对感知包长和传输包长进行联合优化以最小化PAoI加权和。仿真结果验证了理论分析的正确性。该研究发现,对于双向中继系统次用户对的PAoI加权和,感知包长和传输包长存在折中关系,该文所采用的交替迭代优化算法能够有效提升系统PAoI性能。

Future cognitive Internet of Things(IoT)applications will rely on time-sensitive short-packet information to control and monitor.This paper analyzes the information freshness of secondary users in the short-packet two-way relay system.In this paper,the age of information(AoI)is used as a performance metric to measure the freshness of information.Based on the short-packet communications theory,the expressions of the packet error rate and the average peak AoI(PAoI)are derived.In addition,the performance under the high signal-to-noise ratio regime is analyzed.Due to imperfect sensing,an alternate iterative optimization algorithm is used to jointly optimize the spectrum sensing time and short-packet length to minimize the average weighted sum PAoI.The simulation results verify the correctness of the theoretical analysis.And it shows that there is a trade-off relationship between the spectrum sensing time and short-packet length,and the proposed algorithm can minimize the average weighted sum PAoI.