过时CSI下全双工中继辅助D2D网络的物理层安全

中继辅助终端直通（devicetodevice,D2D）网络通过与蜂窝网络共享频谱提高D2D用户的频谱效率和蜂窝用户（cellular user,CU）的物理层安全性。为进一步改善其性能，可以在基站和D2D链路的中继节点采用天线选择以及在中继节点采用全双工技术。然而，由于存在反馈时延和移动性，用于蜂窝链路和所有D2D链路天线选择的信道状态信息（channelstateinformation,CSI）均可能是过时的，针对该场景下的物理层安全性和可靠性问题，提出一种主动窃听和过时CSI场景下基站和中继节点均采用发射天线选择的全双工中继辅助D2D网络安全模型，推导CU的中断概率、遍历容量、非零安全容量概率、安全中断概率、渐近安全中断概率的解析表达式。数值计算与仿真结果均表明，基站发射天线数、中继干扰天线数越多，CU的安全性能越好；过时的CSI会降低CU的中断性能和安全性能。

Physical layer security of full-duplex relay-assisted D2D networks under outdated CSI

The relay aided device to device (D2D) network can improve the spectrum efficiency of D2D users and the physical layer security of cellular user (CU) by sharing spectrum with the cellular network.To further improve their performance, transmit antenna selection can be used at the base station and the relay node of the D2D link, and full duplex technology can be used in the relay node.However, due to the feedback delay and mobility, the channel state information (CSI) used for the antenna selection of cellular link and all D2D links may be outdated.For the physical layer security and reliability in the above scenario, security model of a full duplex relay aided D2D network was proposed in the presence of active eavesdropping and outdated CSI, in which the base station and relay nodes both used transmit antenna selection.The closed-expressions for outage probability, ergodic capacity, probability of non-zero secrecy capacity, secure outage probability, asymptotic secure outage probability of relay aided D2D networks were derived.The numerical calculation and simulation results show that the more the number of base station transmit antennas and relay jamming antennas are, the better the CU security performance is.The outdated CSI will deteriorate the outage and security performance of CU.