On Secure QoS-based NOMA Networks with Multiple Antennas and Eavesdroppers over Nakagami-m Fading

Abstract

In this paper, we study the physical layer security of a downlink multi-input single-output non-orthogonal multiple access (NOMA) system, in which transmit antenna selection (TAS) scheme, users’ quality of service (QoS) requirements, Nakagami-m fading channel, and user selection solution are considered for secure NOMA transmission. Specifically, we investigate the scenario that a base station (BS) (source) communicates with two legitimate user (LU) clusters with different priority depending on their QoS requirements in the presence of multiple passive eavesdroppers over Nakagami-m fading. To enhance the secrecy performance, we examine a TAS scheme and a user selection method. In this context, prior to transmission, a transmit antenna and a user in high-priority LU cluster are jointly selected to maximize the channel quality of the link from the BS to the selected user. Furthermore, together with the selected high-priority user, a user in low-priority LU cluster, which has the best channel condition, is chosen for performing two-user NOMA. In order to evaluate the secrecy performance, tight and asymptotic closed-form expressions of secrecy outage probability for selected LUs and overall system are derived. Our theoretical results confirmed by Monte–Carlo simulation show that in QoS-based NOMA system, high-priority users cause the higher effects on the overall secrecy performance in comparison with low-priority users. Finally, these results also indicate that our proposed communication protocol achieves the secrecy performance greater than conventional protocol.

KEYWORDS:

• NOMA
• Physical layer security
• Secrecy capacity
• Secrecy outage probability
• SIC
• TAS

Notes

1 As mentioned above, only the positive integer values of the fading parameters (i.e. $m_{\stackrel{⌢}{H}}$ and $m_{\stackrel{⌢}{L}}$) are considered to obtain the expressions (4) and (5). Thus, the general values of these parameters, as investigated in [20], are not analysed in this paper.

2 In this paper, it is assumed that perfect SIC is obtained at user$\stackrel{⌢}{L}$, as well used in [15, 16]. In fact, this assumption can bring the positive results of secrecy performance for user $\stackrel{⌢}{L}$ but may be difficult to obtain in a practical scenario.

Additional information

Funding

This research is funded by Vietnam National Foundation for Science and Technology Development (NAFOSTED) under [grant number 102.04-2017.301].

Notes on contributors

Tam Nguyen Kieu

Tam Nguyen Kieu was born in Phu Yen Province, Vietnam. He received his MSc from the University of Transport and Communications, Vietnam in 2012. Now, he is a doctorial student at VSB-Technical University of Ostrava, Czech Republic. His research interests include the wireless communication, WiMax and energy harvesting. Email: [email protected]

Duc-Dung Tran

Duc-Dung Tran received BE in electronics and telecommunications from the University of Sciences, Hue, Vietnam, in 2013 and MSc in computer sciences from Duy Tan University, Danang, Vietnam, in 2016. He currently works for Duy Tan University as a researcher. His research interests include 5G wireless communication networks, physical layer security, wireless energy harvesting networks, MIMO systems. Corresponding author. Email: [email protected]

Dac-Binh Ha

Dac-Binh Ha received BS in radio technique, MSc and PhD in communication and information system from the Huazhong University of Science and Technology (HUST), China, in 1997, 2006, and 2009, respectively. He is currently the dean of Faculty of Electrical and Electronics Engineering, Duy Tan University, Danang, Vietnam. His research interests include secrecy physical layer communications, MIMO systems, combining techniques, cooperative communications, cognitive radio, wireless energy harvesting networks and image processing. Email: [email protected]

Miroslav Voznak

Miroslav Voznak is a professor at VSB-Technical University of Ostrava, Czech Republic. His research interests include wireless communications, next-generation networks, IP telephony, security and speech quality, 5G wireless communication networks. Email: [email protected]