Abstract Physical-layer security is a critical challenge in optical wireless non-orthogonal multiple access (NOMA) systems, where broadcast transmission inherently risks eavesdropping. While intelligent reflecting surfaces (IRS) improve coverage, they introduce additional security vulnerabilities under imperfect channel state information. This paper proposes a joint security optimization framework for IRS-assisted optical NOMA that integrates transmit beamforming, artificial noise, cooperative jamming, and IRS phase-shift control under 64-quadrature amplitude modulation (QAM). An iterative strategy maximizes secrecy performance amidst channel uncertainty. Simulations demonstrate a 47 % improvement in secrecy capacity over conventional optical NOMA and a 25 % increase in secrecy rate compared to standard IRS-assisted designs without jamming. A learning-assisted power allocation mechanism further adapts to dynamic channels for robust mobile performance. The framework effectively enhances confidentiality, robustness, and spectral efficiency for secure high-capacity optical networks.
Sharma et al. (Sat,) studied this question.