Covert Rate Characterization under Multi-Antenna Detection:A Study on Warden’s CSI Availability and Noise Uncertainty  

作　　者：Zhang Yuchen Xiao Sa Wang Jianquan Ning Boyu Yuan Xiaojun TangWanbin 

机构地区：[1]National Key Laboratory of Wireless Communications,University of Electronic Science and Technology of China,Chengdu 611731,China [2]Kash Institute of Electronics and Information Industry,Kash,844000 China

出　　处：《China Communications》2025年第2期143-159,共17页中国通信(英文版)

基　　金：supported in part by the National Natural Science Foundation of China under Grants 62301117,62001094,and U19B2014;in part by the National Key Laboratory of Wireless Communications Foundation under Grant 2023KP01602;in part by the Natural Science Foundation of Xinjiang Uygur Autonomous Region under Grant 2022D01B184 and 2022D01A297.

摘　　要：In this paper,we investigate covert communications under multi-antenna detection,and explore the impacts of the warden’s channel state information(CSI)availability and the noise uncertainty on system covert capability.The detection performance at warden is analyzed in two cases under the perfect and statistical CSI at warden,respectively.In particular,for the former one,the warden utilizes the likelihood ratio(LR)detector,while for the latter one,the generalized likelihood ratio(GLR)detector is adopted.We first consider the scenario where the blocklength is finite,and demonstrate that the covert rate under both cases asymptotically goes to zero as the blocklength goes to infinity.Subsequently,we take the noise uncertainty at the warden into account which leads to positive covert rate,and characterize the covert rate for infinite blocklength.Specially,we derive the optimal transmit power for the legitimate transmitter that maximizes the covert rate.Besides,the rate gap under two cases,with different CSI availability at the warden,can be presented in closed form.Finally,numerical results validate the effectiveness of our theoretical analysis and also demonstrate the impacts of the factors studied on the system covertness.

关 键 词：channel state information covert communications multiple antenna noise uncertainty 

分 类 号：TN820[电子电信—信息与通信工程] TN918