Secrecy Outage Probability of Energy-Harvesting Cooperative NOMA Transmissions With Relay Selection
Secrecy Outage Probability of Energy-Harvesting Cooperative NOMA Transmissions With Relay Selection
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DOI：
10.1109/tgcn.2020.2999815
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发表时间：
2020-05
影响因子：
4.8
通讯作者：
Abdelhamid Salem;Leila Musavian;Eduard Axel Jorswieck;S. Aïssa
中科院分区：
文献类型：
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作者：
Abdelhamid Salem;Leila Musavian;Eduard Axel Jorswieck;S. Aïssa
提出并比较了三种在协作能量采集(EH)通信中实现安全非正交多址接入的中继选择技术。在协作中继系统中，源节点在被动窃听者存在的情况下，通过放大转发EH中继与多个用户进行通信。中继选择是一种两阶段策略，第一阶段以达到用户的目标数据速率为目标，第二阶段以优化保密中断概率为目标。对于三种情况：i)当窃听者的信道状态信息(CSI)未知时，考虑两阶段传统的中继选择方案；ii)当窃听者的CSI已知时，使用两阶段最优中继选择方案；以及iii)当多个中继器参与向终端用户转发信号时，推导出新的隐蔽中断概率的显式解析表达式。给出了蒙特卡罗仿真结果，并研究了系统主要参数对其保密性的影响。特别是，最优中继选择方案在保密中断概率方面优于传统方案和多中继方案，并且随着中继数目的增加，这种优势变得更加明显。
Three relay selection techniques, aiming at achieving secure non-orthogonal multiple access in cooperative energy-harvesting (EH) communications, are proposed and compared. In the cooperative relaying system, the source node communicates with multiple users through amplify-and-forward EH relays in the presence of a passive eavesdropper. The relay selection is a two-stage strategy, where the first stage aims at achieving the users’ target data rate, and the second aims at optimizing the secrecy outage probability. New explicit analytical expressions for the secrecy outage probability are derived for three operating scenarios: i) when the channel state information (CSI) of the eavesdropper is unknown, and a two-stage conventional relay selection scheme is considered, ii) when CSI of the eavesdropper is known, and a two-stage optimal relay selection scheme is used, and iii) when multiple relays participate in forwarding the signal to the end users. Monte-Carlo simulations are provided to confirm the derivations, and the effects of the main system parameters on its secrecy are investigated. In particular, it is shown that the optimal relay selection scheme outperforms the conventional and the multiple-relays schemes in terms of secrecy outage probability, and that this superiority becomes more obvious when the number of the relays increases.