Secure coordinated direct and untrusted relay transmissions via interference engineering  

作　　者：Lu LV Zan LI Haiyang DING Yuchen ZHOU Jian CHEN 

机构地区：[1]State Key Laboratory of Integrated Services Networks,Xidian University,Xi’an 710071,China [2]National Mobile Communications Research Laboratory,Southeast University,Nanjing 210096,China [3]School of Information and Communications,National University of Defense Technology,Wuhan 430035,China

出　　处：《Science China(Information Sciences)》2022年第8期209-223,共15页中国科学（信息科学）（英文版）

基　　金：supported by National Natural Science Foundation of China (Grant Nos. 61901313, 61941105, 61771366, 61901312, 61971320);National Natural Science Foundation of China for Outstanding Young Scholars (Grant No. 61825104);Natural Science Fundamental Research Plan of Shaanxi Province (Grant No. 2020JQ-306);China Postdoctoral Science Foundation (Grant Nos. BX20190264, 2019M650258);Open Research Fund of National Mobile Communications Research Laboratory, Southeast University (Grant No. 2020D07)。

摘　　要：This paper investigates the physical layer security issue of the coordinated direct and untrusted relay transmissions, considering both uplink and downlink scenarios. To effectively prevent the untrusted relay from eavesdropping on the confidential information it receives, two novel interference-assisted jamming schemes are proposed, where the inter-user interference and the artificial noise are intelligently engineered to degrade the signal reception quality at the untrusted relay, therefore enhancing the physical layer security for the uplink and downlink coordinated transmission, respectively. For each of the two proposed jamming schemes, a lower bound for the ergodic secrecy sum rate(ESSR) is derived in closed form to evaluate the secrecy performance. To obtain more system design insights, we further provide an asymptotic analysis for the ESSR scaling laws over the regimes of the high signal-to-noise ratio and a large number of antennas at the base-station. We carry out computer simulations to confirm the accuracy of the derived theoretical analysis.Our simulation results show that the proposed jamming schemes achieve a similar asymptotic performance limit to the case of using a trusted relay. Moreover, the proposed jamming schemes guarantee perfect security for both uplink and downlink coordinated transmissions, and yield a significant ESSR improvement compared with three other baseline schemes.

关 键 词：physical layer security untrusted relay interference exploitation coordinated transmission ergodic secrecy rate 

分 类 号：TN918[电子电信—通信与信息系统]