Author Identifier (ORCID)
Shihao Yan: https://orcid.org/0000-0002-4586-1926
Abstract
Simultaneously transmitting and reflecting reconfigurable intelligent surfaces (STAR-RIS) and non-orthogonal multiple access (NOMA) are two promising technologies for extending coverage and enhancing spectral efficiency in multi user wireless communication systems. However, their integration also introduces significant security challenges. Most existing studies on the physical layer security (PLS) of STAR-RIS assisted NOMA systems rely on idealized assumptions, such as independent fading channels and perfect successive interference cancellation (SIC), which fail to reflect realistic propagation environments. To address this gap, we propose a novel analytical framework to evaluate the joint impact of channel correlation and imperfect SIC on the secrecy performance of STAR-RIS assisted NOMA systems. Specifically, we derive the statistical characteristics of the cascaded channel gains for both legitimate users and the eavesdropper under correlated channels. Using the moment-matching method, we obtain closed-form expressions for the cumulative distribution functions (CDFs) of the signal-to-interference-plus-noise ratios (SINRs) of the legitimate users and the probability density function (PDF) of the signal-to-noise ratio (SNR) at the eavesdropper. These results enable our derivation of exact closed-form expressions for the secrecy outage probability (SOP) and the analysis of the asymptotic SOP in the high-SNR regime, from which we determine the secrecy diversity order. Our theoretical analysis and simulation results reveal that: (i) The STAR-RIS assisted NOMA system outperforms its OMA counterpart in terms of secrecy performance. Notably, the secrecy advantage for the near user becomes more pronounced at high SNRs, while for the far user, the advantage is more evident at low SNRs under channel correlation. (ii) The detrimental effect of imperfect SIC diminishes as the target secrecy rate decreases. (iii) The secrecy diversity order is influenced by both the number of STAR-RIS elements and the level of channel correlation.
Document Type
Journal Article
Date of Publication
1-1-2025
Publication Title
IEEE Transactions on Vehicular Technology
Publisher
IEEE
School
School of Science
Creative Commons License
This work is licensed under a Creative Commons Attribution-No Derivative Works 4.0 License.
Comments
This is an Author's Accepted Manuscript of an article published by IEEE. © 2025 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.
Feng, Y., Zhu, X., Yang, N., Yan, S., & Wang, H. (2025). Secure performance of STAR-RIS assisted NOMA system with channel correlation and imperfect SIC. IEEE Transactions on Vehicular Technology. Advance online publication. https://doi.org/10.1109/TVT.2025.3599396