基于人工噪声和NOMA安全传输策略分析研究

Secrecy Sum Rate Maximization with Artificial-Noise-Aided Beamforming for Non-Orthogonal Multiple Access

物理层安全技术利用无线信道特征来实现信息的安全通信,有效克服了传统安全技术依赖于窃听者有限计算能力的缺陷。此外,由于非正交多址接入技术(NOMA)满足多用户同时接入,大大提高了频谱效率而备受关注。针对下行多输入单输出(MISO)系统的安全和速率(SSR)最大化问题,提出了一种基于人工噪声(AN)的NOMA波束成形方案;构建了满足用户最小安全中断概率的约束条件下的SSR最大化问题,并确定最优传输参数闭合表达式。最后,通过数值结果验证了所提方案优于传统的基于AN的正交多址方案和没有AN的NOMA方案。

The physical layer security technology utilizes the wireless channel characteristic to realize the secure communication,and effectively overcomes the traditional security technology based on the eavesdropper limited ability flaw,and then satisfies the wireless communication reliability and the security demand.Physical layer security as a complementary and alternative cryptographic method to defend against eavesdroppers from information-theoretic perspective has drawn numerous research interests.Non-orthogonal multiple access(NOMA) has been recognized as a promising technique for providing high data rates for future wireless networks.In this paper,we investigate the secrecy sum rate(SSR) maximization for a downlink multiple-input single-output(MISO) system which consists of a multiple antenna base station,multiple legitimate users,and an eavesdropper.In order to maximize SSR of the MISO system under the constraint of secrecy outage probability,we propose a joint NOMA and artificial noise(AN) aided beamforming(NOMA-AN) scheme.Furthermore,we determine the optimal transmission parameters through solving an equation set for our considered systems.Numerical results validate our proposed NOMA-AN scheme outperforms the conventional AN-based orthogonal multiple access(OMA-AN) scheme and NOMA without AN scheme.