基于无线携能的协作NOMA系统安全性能研究

针对中继能量受限的多用户无线窃听场景,提出了一种基于无线携能的协作非正交多址接入(NOMA)安全传输机制并进行了性能分析。该传输机制首先对多天线基站进行最优发射天线选择,引入协作NOMA的全双工技术提高传输可靠性与频谱利用率,采用无线携能技术克服中继节点由于功耗过大引起的能量不足问题。为进一步衡量所提传输机制的系统性能,推导了用户的中断概率和安全中断概率并进行了系统性能分析。数值结果表明,通过合理设置NOMA功率分配比以及无线携能功率分割比有利于提高系统的性能,所提传输机制相对于协作NOMA和传统NOMA传输机制安全中断性能分别提高了33%与59%。

Security performance of cooperative NOMA system based on SWIPT

Aiming at the multi-user wireless eavesdropping scenario with limited energy in relay node, a security transmission scheme is proposed based on the cooperative non-orthogonal multiple access (NOMA) technology and the simultaneous wireless information and power transfer (SWIPT) technology. In this scheme, the transmit antenna selection mechanism is carried out in the multi-antenna base station. Firstly, the full-duplex cooperative relay technology is utilized for improving transmission reliability and spectrum utilization in NOMA system, and the SWIPT technology is utilized for overcoming the energy shortage problem caused by excessive power consumption of the relay node. Furthermore, the closed-form expressions of outage probability and secrecy outage probability are derived for further measuring the system performance. Finally, the effect of key system parameters on system performance is comprehensively analyzed through asymptotic analysis. Numerical results show that the system performance can be improved by reasonably setting the power allocation coefficient of NOMA user and the power splitting ratio of SWIPT user. Compared with the cooperative NOMA and the traditional NOMA transmission mechanism, the proposed scheme has improved the security performance by 33% and 59%, respectively.Keywords: simultaneous wireless information and power transfer (SWIPT);