Non-orthogonal multiple access systems will face serious physical layer security (PLS) problems in the present of internal eavesdropper. However, in the existing schemes, it’s difficult to always guarantee the positive secrecy rate of the system. To this end, we consider the PLS against internal eavesdropping in two-users scenario and the beamforming design and optimal power allocation problems are given. The developed analytical results demonstrate that the proposed scheme can absolutely achieve positive secrecy rate if provided sufficient power. Simulation results show that the performance of proposed scheme is better than the existing solutions.

中文翻译：

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保证 NOMA 系统的正保密率防止内部窃听

在存在内部窃听者的情况下，非正交多址系统将面临严重的物理层安全（PLS）问题。然而，在现有方案中，很难始终保证系统的正保密性。为此，我们考虑了在两个用户场景下防止内部窃听的 PLS，并给出了波束成形设计和优化功率分配问题。开发的分析结果表明，如果提供足够的功率，所提出的方案绝对可以达到正保密率。仿真结果表明，所提出方案的性能优于现有方案。