基于NOMA系统的物理层安全技术研究

Research on Physical Layer Security Technology Based on NOMA Systems

摘要: 为解决非正交多址接入(NOMA)系统因功率域叠加传输导致的窃听风险，本文构建单小区下行NOMA安全通信模型，定义平均保密速率(ASR)、保密中断概率(SOP)，设计固定功率分配(FPA)、安全最大化功率分配(S-Max)，通过MATLAB (1 × 10⁵次蒙特卡洛)仿真验证。结果表明：S-Max在中高功率区ASR较FPA提升38%，AN-aided在低功率及窃听者靠近场景优势显著，SEE峰值提升55%。本研究为5G/6G NOMA系统物理层安全设计提供可行思路。

Abstract: To address the eavesdropping risk of Non-Orthogonal Multiple Access (NOMA) systems caused by power-domain superposed transmission, this paper constructs a single-cell downlink NOMA secure communication model, defines core indicators including Average Secrecy Rate (ASR), Secrecy Outage Probability (SOP), and designs three strategies: Fixed Power Allocation (FPA), Security-Maximizing Power Allocation (S-Max). Verification is conducted via MATLAB simulations with 1 × 10⁵ Monte Carlo iterations. Results show that in the medium-to-high power region, the ASR of S-Max is 38% higher than that of FPA; the AN-aided strategy demonstrates significant advantages in low-power scenarios and when eavesdroppers are in close proximity, with the peak SEE increased by 55%. This research provides feasible insights for the physical layer security design of 5G/6G NOMA systems.