# Improving Physical Layer Security of Cooperative NOMA System with Wireless-Powered Full-Duplex Relaying

^{1}

^{2}

^{*}

## Abstract

**:**

## 1. Introduction

- We investigate a cooperative NOMA system with wireless-powered FD relaying. In particular, an AN-aided secrecy enhancing scheme is proposed for self-sustained FD relay to reduce the decoding performance of the eavesdropper, where the FD relay can harvest energy from the source and SI signal.
- For the proposed AN-aided secrecy enhancing scheme, the lower bound of the ergodic secrecy sum rate (ESSR) is analyzed with closed-form expressions. In particular, the proposed scheme achieves a positive lower bound of ESSR, indicating that perfect secrecy can be guaranteed.
- Monte Carlo simulations are provided to verify the accuracy of the theoretical analysis, and the superiority of the proposed AN-aided secure transmission scheme over the benchmark scheme is also presented. This indicates that adopting AN at the wireless-powered FD relay can significantly improve the secrecy performance in the cooperative NOMA systems.

## 2. System Model and the Proposed Scheme

#### 2.1. System Model

#### 2.2. Proposed Scheme

## 3. Performance Analysis

## 4. Simulations

## 5. Conclusions

## Author Contributions

## Funding

## Conflicts of Interest

## References

- Zeng, Y.; Zhang, R. Full-duplex wireless-powered relay with self-energy recycling. IEEE Wirel. Commun. Lett.
**2015**, 4, 201–204. [Google Scholar] [CrossRef] [Green Version] - Ding, Z.; Fan, P.; Poor, H.V. On the coexistence between full-duplex and NOMA. IEEE Wirel. Commun. Lett.
**2018**, 7, 692–695. [Google Scholar] [CrossRef] - Rauniyar, A.; Engelstad, P.E.; Osterbo, O.N. Performance Analysis of RF Energy Harvesting and Information Transmission Based on NOMA with Interfering Signal for IoT Relay Systems. IEEE Sens. J.
**2019**, 19, 7668–7682. [Google Scholar] [CrossRef] [Green Version] - Yang, S.; Ren, Y.; Lu, G.; Wang, J. Optimal resource allocation for full-duplex wireless-powered relaying with self-energy recycling. In Proceedings of the 2019 11th International Conference on Wireless Communications and Signal Processing (WCSP), Xi’an, China, 23–25 October 2019; pp. 1–6. [Google Scholar]
- Liu, Y.; Ding, Z.; Elkashlan, M.; Poor, H.V. Cooperative Non-orthogonal Multiple Access with Simultaneous Wireless Information and Power Transfer. IEEE J. Sel. Areas Commun.
**2016**, 34, 938–953. [Google Scholar] [CrossRef] [Green Version] - Do, N.T.; Da Costa, D.B.; Duong, T.Q.; An, B. A BNBF User Selection Scheme for NOMA-Based Cooperative Relaying Systems With SWIPT. IEEE Commun. Lett.
**2017**, 21, 664–667. [Google Scholar] [CrossRef] [Green Version] - Guo, C.; Zhao, L.; Feng, C.; Ding, Z.; Chen, H.-H. Energy Harvesting Enabled NOMA Systems with Full-Duplex Relaying. IEEE Trans. Veh. Technol.
**2019**, 68, 7179–7183. [Google Scholar] [CrossRef] [Green Version] - Sun, L.; Du, Q. Physical layer security with its applications in 5G networks: A review. China Commun.
**2017**, 14, 1–14. [Google Scholar] [CrossRef] - Chen, J.; Yang, L.; Alouini, M.-S. Physical Layer Security for Cooperative NOMA Systems. IEEE Trans. Veh. Technol.
**2018**, 67, 4645–4649. [Google Scholar] [CrossRef] [Green Version] - Feng, Y.; Yang, Z.; Yan, S. Non-orthogonal multiple access and artificial-noise aided secure transmission in FD relay networks. In Proceedings of the 2017 IEEE Globecom Workshops (GC Wkshps), Singapore, 4–8 December 2017; pp. 1–6. [Google Scholar]
- Liu, C.; Zhang, L.; Xiao, M.; Chen, Z.; Li, S. Secrecy performance analysis in downlink NOMA systems with cooperative full-duplex relaying. In Proceedings of the 2018 IEEE International Conference on Communications Workshops (ICC Workshops), Kansas City, MO, USA, 20–24 May 2018; pp. 1–6. [Google Scholar]
- Lv, L.; Jiang, H.; Ding, Z.; Yang, L.; Chen, J. Secrecy-Enhancing Design for Cooperative Downlink and Uplink NOMA with an Untrusted Relay. IEEE Trans. Commun.
**2020**, 68, 1698–1715. [Google Scholar] [CrossRef] - Lei, H.; Yang, Z.; Park, K.-H.; Ansari, I.S.; Guo, Y.; Pan, G.; Alouini, M.-S. Secrecy Outage Analysis for Cooperative NOMA Systems with Relay Selection Schemes. IEEE Trans. Commun.
**2019**, 67, 6282–6298. [Google Scholar] [CrossRef] [Green Version] - Salem, A.; Musavian, L.; Jorswieck, E.A.; Aissa, S. Secrecy Outage Probability of Energy-Harvesting Cooperative NOMA Transmissions With Relay Selection. IEEE Trans. Green Commun. Netw.
**2020**, 4, 1130–1148. [Google Scholar] [CrossRef] - Guo, C.; Zhao, L.; Feng, C.; Ding, Z.; Wang, H.-M. Secrecy Performance of NOMA Systems With Energy Harvesting and Full-Duplex Relaying. IEEE Trans. Veh. Technol.
**2020**, 69, 12301–12305. [Google Scholar] [CrossRef] - Yang, S.; Ren, Y.; Lu, G. Optimal power allocation for wireless-powered full-duplex cooperative NOMA system with partial CSI. In Proceedings of the 2020 IEEE Globecom Workshops (GC Wkshps), Taipei, Taiwan, 7–11 December 2020; pp. 1–5. [Google Scholar]
- Ding, Z.; Yang, Z.; Fan, P.; Poor, H.V. On the Performance of Non-Orthogonal Multiple Access in 5G Systems with Randomly Deployed Users. IEEE Signal Process. Lett.
**2014**, 21, 1501–1505. [Google Scholar] [CrossRef] [Green Version] - Gradshteyn, I.S.; Ryzhik, I.M. Table of Integrals, Series, and Products, 7th ed.; Academic: New York, NY, USA, 2007. [Google Scholar]
- Abramowitz, M.; Stegun, I. Handbook of Mathematical Functions with Formulas, Graphs, Mathematical Tables; Dover: New York, NY, USA, 1972. [Google Scholar]

**Figure 5.**ESSR versus the whole transmit power ${P}_{s}$ with different ${U}_{1}$’s power allocation ratios ${\alpha}_{1}$.

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. |

© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).

## Share and Cite

**MDPI and ACS Style**

Ren, Y.; Tan, Y.; Makhanbet, M.; Zhang, X.
Improving Physical Layer Security of Cooperative NOMA System with Wireless-Powered Full-Duplex Relaying. *Information* **2021**, *12*, 279.
https://doi.org/10.3390/info12070279

**AMA Style**

Ren Y, Tan Y, Makhanbet M, Zhang X.
Improving Physical Layer Security of Cooperative NOMA System with Wireless-Powered Full-Duplex Relaying. *Information*. 2021; 12(7):279.
https://doi.org/10.3390/info12070279

**Chicago/Turabian Style**

Ren, Yuan, Yixuan Tan, Meruyert Makhanbet, and Xuewei Zhang.
2021. "Improving Physical Layer Security of Cooperative NOMA System with Wireless-Powered Full-Duplex Relaying" *Information* 12, no. 7: 279.
https://doi.org/10.3390/info12070279