Dual-Hop Transmission and Multiple Relays for Performance Analysis of Designing Physical Layer Security for IoT Networks

Nguyen, Nhan Duc; Le, Anh-Tu; Do, Dinh-Thuan; Munochiveyi, Munyaradzi

doi:https://doi.org/10.1155/2022/4915583

Journal of Sensors

On this page

Abstract Introduction System Model Conclusions Appendix Data Availability Conflicts of Interest Acknowledgments References Copyright Related Articles

Special Issue

Physical Layer Security for Sensor-enabled Heterogeneous Networks

View this Special Issue

Research Article | Open Access

Volume 2022 | Article ID 4915583 | https://doi.org/10.1155/2022/4915583

Dual-Hop Transmission and Multiple Relays for Performance Analysis of Designing Physical Layer Security for IoT Networks

Nhan Duc Nguyen,¹Anh-Tu Le,²Dinh-Thuan Do,³and Munyaradzi Munochiveyi⁴

Academic Editor: Akilesh Pathak

Received24 Aug 2021

Revised04 Sept 2021

Accepted28 Aug 2022

Published15 Sept 2022

Abstract

This article presents a secure performance metric of a downlink nonorthogonal multiple access (NOMA) in the presence of interference from the traditional user. In the context of NOMA, we deploy two-hop transmission to improve the performance of destinations. Further, multiple relays are implemented to aid robust signal-to-interference-plus-noise ratio (SINR) at destinations. We derive a closed-form expression of secure outage probability (SOP) to characterize security concerns in the case an eavesdropper exists in the overage of second hop transmission. We verify all expressions by employing Monte Carlo simulations.

1. Introduction

1.1. Motivation

The nonorthogonal multiple access (NOMA) procedures can progress the effectiveness of the spectrum since it can allocate the same frequency band to multiple users by differentiating the power levels of each user in the cluster [1–5]. Successive interference cancellation (SIC) is a technique that is achieved at the receiver’s end to distinguish the received signals [6]. The addition of the NOMA technique into cognitive radio (CR) networks has shown advantages like improving better spectral efficiency and also serving increased numerous secondary users, realizing 5th generation (5G) communication systems [7]. In [8], the author mentioned repetition-based NOMA, which can achieve high diversity gain by utilizing repetition. This method is different compared to the conventional power domain NOMA as all users possess the same power level but a diverse number of repetitions. Since it has high diversity gain, we can achieve low outage probability with no need for instant channel state information (CSI) response for power allocation. The key parameters are constrained to sustain the outage probability (OP) lesser than the target value by deriving a closed-form expression of OP. Moreover, in [9] the authors examined the impact of imperfect CSI and imperfect SIC on NOMA-enabled coordinated direct and relay transmission (CDRT) network consisting of a base station communicating directly with a cell-centered user and an FD relay responsible for communicating with a user located at the cell-edge. Here, the authors obtained exact OP and ergodic rates for the users under the assumption of imperfect CSI and SIC. Also, the authors considered the channel links to be operating under Nakagami-m fading conditions. Numerical results demonstrated the adverse impact of imperfect CSI and SIC on the OP performance of the system. To remedy this, the authors determined a suitable base-station power allocation coefficient to ensure fair outage for both network users under imperfect CSI and SIC conditiIn [10], the authors studied the performance of downlink NOMA in vehicular communication over double Rayleigh fading channels, where a base station communicates with a far-user and a near-user. Due to the impact of mobility, the authors derived OP expressions of the individual users as well as for the overall system considering the scenario of when the NOMA rate falls below the system target rate and when Orthogonal Multiple Access (OMA) outperforms the NOMA system. Additionally, the authors derived ergodic capacity and Average Bit Error Rate (ABER) expressions. Numerical results showed that in terms of OP and ergodic capacity, NOMA outperforms OMA, however in terms of ABER, OMA outperforms NOMA as OMA users lack inter-user interferences.

In the presence of massive communications, security becomes the major apprehension among the users. Because of the diverse nature of radio propagation, the communication networks are exposed to the eavesdropper, and this also becomes a major challenge for researchers to overcome [11]. We know that cognitive radio (CR) networks permit unlicensed users in the spectrum that increases the risk of wiretapping, particularly when the users are malicious. In previous generations, cryptographic algorithms are utilized in the top layers to protect the data. But these algorithms are time-consuming and complicated since they have to perform encryption and decryption to protect the data [12]. Whereas, Physical Layer Security (PLS) has become the single utmost significant tactic to secure the data. Since the evolution of CR networks, there has been a giant exploration going on to enhance the performance of PLS [13–20]. Authors in [13, 14] have designed CR networks user-scheduling schemes, to improve the secrecy performance by achieving multiuser diversity for a primary user under the Quality of Service (QoS) limitation. Authors in [13] have shown that the scheme can achieve maximum diversity, whereas in [14], the three user-scheduling schemes show that the secrecy performance rate is significantly enhanced by growing the number of cognitive users. Authors in [15] have employed multiple relay selection policies where one relay aids in transmitting the information and the other acts as a friendly jammer. This way, the authors were able to obtain efficient performance in terms of secrecy outage of the cognitive transmission system. In [16], the authors proposed an Artificial Noise (AN) assisted optimal beamforming scheme, in which the ergodic secrecy rate is maximized by obtaining optimal power allocation among data and AN signal.

Until now, all the works discussed are based on Rayleigh fading channels, whereas the works in [17–20] are based on Nakagami-m fading channels. In [17] the authors have provided a consistent method to identify the secrecy performance of the framework by determining the mathematical expression of Secrecy Outage Probability (SOP) and nonzero secrecy capacity probability. Authors in [18] have considered a multiantenna networks approach by proposing optimal and suboptimal antenna selecting schemes for secured underlay CR networks. The authors have also derived mathematical descriptions of the exact and asymptotic SOP of both schemes. In [19], the authors considered enhancing the secrecy performance by increasing the number of relays or legitimate channel Nakagami parameters. In [20], the authors considered PLS in a CR network with multiple primary and secondary users. PLS also plays a pivotal role in NOMA communications in terms of secure transmission [20–25]. Especially, the authors in [24–26] mentioned that the secrecy performance of the NOMA technique outperforms the Orthogonal Multiple Access (OMA) technique. Authors in [24] optimized the transmit power to achieve a maximum secrecy rate. Along with these techniques, authors in [25, 26] have adopted beamforming and power allocation policies. In [25], the authors considered a NOMA-assisted multicast-unicast system and studied the risk of multicast receivers intercepting the unicasting messages. Whereas, in [26], the cell-edge user is considered an eavesdropper who spies on the data and information of a cell-center user. Authors in [27] have considered the user pairing method to improve the security of the NOMA system. In this model, the users are arranged according to their channel gains and paired with unlike channel gains to achieve the NOMA protocol. The outcomes explain that the secrecy diversity order of the user is equal to the ascending direction of channel ordering.

1.2. Related Works

Recently, several authors have been interested in studying secrecy in NOMA-aided Full-Duplex (FD) systems in the vicinity of eavesdroppers. One of these works is found in [28], where the authors investigated the SOP of NOMA-assisted dual-hop FD amplify-and-forward networks in the presence of a colluding and noncolluding wiretapping eavesdropper. This system comprised a base station, a multiple antenna FD relay, an eavesdropper, and multiple users. In [29], the authors studied the trade-off between reliability and security of PLS techniques in cooperative NOMA-enabled dual-hop Internet-of-Things (IoT) systems under in-phase and quadrature-phase imbalance (IQI) conditions at the transceivers. The system consisted of a single source, a relay, an eavesdropper, and multiple devices. Here, the authors derived closed-form OP and Intercept Probability (IP) expressions. The simulation results showed that IQI increases OP while reducing IP, demonstrating that reliability is impacted but security is enhanced. In [30], the author considered the PLS of a dual-hop NOMA system consisting of a single source, relay, an eavesdropper, and numerous users. The authors maximized the system’s secure sum rate over different source subcarriers with optimal power allocation. Further, the authors solved the nonconvex and mixed-integer programming problem via duality theory. Simulation results demonstrated that the proposed system outperforms OMA systems. In [31], the authors examined the Strictly Positive Secrecy Capacity (SPSC) and SOP of a NOMA-aided dual-hop DF system under different scenarios of untrusted and trusted relays. Here, the network is made up of a base station, a DF relay, an eavesdropper, and a multiple users. The authors derived exact expressions for SPSC and SOP under independent Rayleigh fading. Moreover, numerical results compared the secrecy performance of the proposed system against OMA. Similarly, in [32], the authors examined the secrecy performance of cooperative downlink and uplink NOMA-aided network with an untrusted relay. To minimize secrecy failure at the untrusted relay, the authors proposed adaptive downlink and uplink jamming strategies. For each strategy, the authors derived lower bound ergodic secrecy sum rates for the proposed system. Furthermore, in [33], the authors considered different scenarios of single and multiple antenna relay configurations at the source and the untrusted relay. In this work, the authors derived closed-form lower bound ergodic secrecy sum rate (ESSR) and proved via simulation results how the proposed system outperforms OMA systems.

Differently, in [34], the authors considered the SOP of a cooperative NOMA-aided system with multiple relays over Nakagami-m fading channels in the presence of an eavesdropper. Here, the authors proposed three different types of relay selection (RS) strategies which are Optimal Single Relay Selection (OSRS), Two-Step Single Relay Selection (TSRS), and Optimal Dual Relay Selection (ODRS). The authors obtained closed-form SOP expressions under different RS strategies. Similarly, in [35], the authors considered the asymptotic SOP of NOMA-assisted multiple-DF relay network over Rayleigh fading channels with two RS schemes—OSRS and TSRS. The authors also derived exact asymptotic SOP for both RS schemes considering fixed and dynamic power allocations. In [36], the authors investigated a cooperative NOMA network with multiple relays, where one relay transmits information and the other relays act as jammers. Here, the authors considered two RS schemes, random and max–min RS. The authors derived closed-form SOP for both RS schemes. Simulation results proved that in the moderate to high signal-to-noise ratio (SNR) region, the proposed scheme obtains a lower SOP than systems without jammers. Also, the max-min RS scheme enhances the SOP in the low SNR range.

However, it would be unreasonable for us not to mention the hidden cost of multiple relays in NOMA-aided massive IoT networks. Large CSI signaling overhead, power allocation feedback, and computational complexity emerge when there are a massive number of devices and relays in NOMA-enabled multiple-relay networks [37, 38]. In such a scenario, feedback delay from the multiple relays becomes a critical issue resulting in channel estimation and synchronization errors in the uplink [37, 38]. Therefore, obtaining perfect CSI is difficult to achieve [37, 38]. These issues are still open research problems, and we welcome more research in this area to enable NOMA-enabled multiple relay networks to be implemented practically.

Furthermore, another area of interest this research work did not consider, but is also worth researching, is the security in simultaneous wireless information and power transfer- (SWIPT-) enabled IoT networks. The authors in [39, 40] proposed a PLS approach for SWIPT-enabled multiple relays IoT network. Additionally, the authors investigated the impact of static power splitting relaying (SPSR) and dynamic power splitting relaying (DPSR) on secure communications in the presence of an eavesdropper. Similarly, in [41], the authors also considered the impact of SPSR and DPSR on the outage and throughput performance for a DF relay SWIPT system, consisting of a single source, multiple relays, and a destination. Differently, in [42], the authors proposed partial and full relay selection techniques for self-energy recycling (S-ER) FD multiple-relay networks, in which the self-interference energy is harvested back at the relay for future use.

1.3. Contributions

In several works, such as [34–36], the authors considered systems with multiple relays and different RS strategies when examining the SOP of such proposed systems. However, the practical issue of interference was not investigated in those works. Therefore, in this work, we propose a NOMA-enabled multiple-relay communication network reliant on partial relay selection (PRS) and investigate the SOP performance of the proposed system. In particular, we take into consideration the aspect of interferences on the NOMA-aided communication system. Table 1 provides a comparison of this work versus the works in [28–36]. Our contributions are listed as follows: (i)We consider transmission assisted by NOMA where a single antenna base station communicates with two devices arranged in a near and far position from the base station in the presence of an eavesdropper, multiple relays, and interference causing conventional user equipment (CUE). The proposed system employs a partial relay selection (PRS) scheme. We study the secrecy performance to determine the downlink SOP and SPSC performance under Rayleigh fading channels(ii)We then determine the signal-to-interference-plus-noise ratios (SINRs) of the two devices and use them to formulate exact SOP and SPSC formulas over Rayleigh fading channels. The derived expressions are validated by Monte Carlo simulations(iii)We analyze and compare the SOP and SPSC under various conditions. In particular, we find that transmit SNR at source, interference channel, the number of relays, and power allocation factors are the main impacts on SOP and SPSC. The obtained numerical results demonstrate that the proposed scheme can increase secrecy and achieve significant SOP via many practical scenarios

1.4. Organization

The rest of this paper is organized as follows. Section 2 describes the downlink NOMA under Rayleigh channels in the dual-hop multiple-relay network in the presence of an eavesdropper and interference. In Section 3, we consider the scenario of NOMA in terms of secrecy outage performance. In Section 4, we consider strictly positive secrecy capacity. In Section 5, we provide extensive numerical simulations, and Section 6 concludes the paper.

2. System Model

A downlink NOMA cooperative relay network is studied, as shown in Figure 1. In particular, we consider a base station , a DF relays, two main destinations , an eavesdropper , and a conventional user equipment (CUE). This CUE causes interference to the two main users as in Figure 1. In addition, the channel coefficient from to , from to , from to _, and from the CUE to are , , _, and , respectively. All channels experience Rayleigh fading, i.e., channel with parameter . Moreover, we assume all channels follow perfect CSI as in [4].

In the first time slot, the source transmits the signal to the selected relay in which and are the power allocation coefficient and , and is the signal dedicated to . Therefore, the received signal is given by where is the transmit power at S, and is . When decodes , the signal-to-interference-plus-noise ratio (SINR) is formulated by where . Following the principle of the NOMA scheme [4], the instantaneous signal-to-noise-ratio (SNR) after using successive interference cancellation (SIC) to detect at is given by

In the second time slot, the relay forwards the signal from source S to . As a result, the received signal is formulated by where is the transmit power at , is the power of the CUE, and is . Next, the SINR at when detecting its own signal is given as where . Next the SINR at when detecting signal is expressed by

By conducting SIC, the SINR to detect signal at is expressed by

To consider the impact of the eavesdropper, we need to compute the received signal at E as where is and . Similar to [43], the instantaneous SNR of detecting the signal are given as

By employing partial relay selection (PRS), the selected relay is chosen as follows based on criteria [44].

3. Performance Analysis

In this section, we derive the closed-form of Secrecy Outage Probability (SOP) for . The secrecy rate of is given as where .

3.1. Secrecy Outage Probability of

Following the result reported in [45], the cumulative distribution functions (CDF) of is given as

Then, the SOP of is computed by where and is the targeted secrecy rate. Substituting (2), (5), and (9) into (12), it can be written such SOP for as where , . Then, the SOP of can be rewritten by where , , _, and . Using Gaussian-Chebyshev Quad with , is given by

3.2. Secrecy Outage Probability of

In here, the SOP of is given by

Proposition 1. The expression SOP of is given by

Proof. Putting (3), (7), and (9) into (17), we have After some variable substitutions and manipulations, (19) can be transformed by where , _, and . Using ([46], 3.352.4), (18) can be obtained.
The proof is completed.

3.3. Asymptotic SOP Analysis

In this section, the asymptotic SOP expression could be derived at high SNR to provide more insights of performance analysis. It can be performed by applying the first-order Maclaurin’s series expansions and use as [46]. The asymptotic SOP of and are expressed as, respectively,

4. Strictly Positive Secrecy Capacity Analysis

In this section, we analyze the strictly positive secrecy capacity (SPSC). Then, the SPSC of the system is given as [47].

Proposition 2. The close-form of SPSC is given by

Proof. See Appendix.

5. Simulation Results

In this section, we present the numerical analysis of our SOP of along with the corroboration of analytical results. The parameters of the system can be expressed in Table 2.

Figure 2 considers the SOP versus transmit SNR while varying DF relays. Different values of SOP can be seen for the two destinations. For and _, the best SOP is achieved with . This shows that the addition of more relays is beneficial to SOP. Furthermore, we observe that the different values of SOP for converge to a single floor at high SNR values. This is due to the absence of SIC at , therefore, the SOP is impacted in high SNR regions despite the number of relays. In addition, NOMA performs better than OMA in the range of SNR from 0 to 30 dB. And NOMA performs better than OMA in all SNR.

In Figure 3, we consider the SOP versus transmit SNR while varying . Different values of SOP can be seen for the two destinations. For and _, the best SOP is achieved with (dB). This shows that increasing impacts on SOP. Also, in Figure 3, the analytical and simulated results closely match. Looking closely at the results, we can see that the SOP of is impacted the most by larger values. Furthermore, we observe that the SOP for approaches a floor at high SNR values for (dB). As in Figure 2, this can be attributed to the lack of SIC at .

In Figure 4, we consider the SOP versus transmit SNR while varying . Different values of SOP can be seen for the two destinations. For and _, the best SOP is achieved with (dB). In Figure 4, the analytical and simulated results closely match. Furthermore, we observe that the different SOP values for converge at a floor at high SNR values, this is due to the absence of SIC at the far user . Hence, is impacted by the interference of the CUE, unlike which employs SIC. Figure 4, clearly shows the impact of SIC on SOP at the different NOMA devices.

In Figure 5, we consider the SOP versus varying in dB with (dB). Different values of SOP can be seen for the two destinations. For and _, the best SOP is achieved with an SNR of 30 dB. Furthermore, the analytical and simulated results closely match. Figure 5 clearly shows the impact of power allocation on SOP at the different NOMA devices.

In Figure 6, we consider the SPSC versus transmit SNR while varying . Different values of SPSC can be observed depending on the value of . The best SPSC curve is achieved with . In Figure 6, the analytical and simulated results closely match. Furthermore, we observe that the different SPSC values converge at a ceiling at high SNR values. Demonstrating that at moderate to high SNR values, the number of relays has no significant impact on the SPSC of the proposed system.

In Figure 7, we consider the SPSC versus transmit SNR while varying . Different values of SPSC can be observed depending on the value of . In Figure 7, the analytical and simulated results closely match. Furthermore, we observe that the different SPSC values approach ceilings at high SNR values. Also, for Figure 7, it is clear that a tenfold increase in significantly reduces the ceiling of SPSC of our system in the moderate to high SNR region. This is due to the increased signal strength at the eavesdropper affecting the proposed system.

In Figure 8, we consider the SPSC versus transmit SNR while varying . Different values of SPSC can be observed depending on the value of . In Figure 8, the analytical and simulated results closely match. Furthermore, we observe that the different SPSC values converge at a similar ceiling at high SNR values. For this figure, unlike in Figure 6, a tenfold increase in interference power does not significantly reduce the ceiling of the SPSC of our system. Demonstrating the reliability and security of our proposed system in the moderate to high SNR region in the presence of interference.

6. Conclusions

In this paper, the PLS problem of two destinations (NOMA users) has been studied in the context of downlink NOMA network under the presence of interference from traditional user CUE. Once an eavesdropper can overhear a signal in second hop transmission, SOP can be evaluated to verify the security of the dual-hop downlink transmission. By designing multiple relays, we can have a higher chance to improve SOP. We found that better SOP can be achieved by having more relays to forward signals. We derived the closed-form expressions SOP and lots of scenarios are presented in numerical simulation to confirm the impact of the studied parameters on secrecy performance. Simulation results are presented to examine the impact of the following parameters, i.e., transmit SNR at source, interference channel, the number of relays, and power allocation factors, on system performance. In future work, we may consider the secure performance of multiple NOMA users.

Appendix

A. Proof of Proposition 2

The SPSC can be expressed as

Next, the first term of can be calculated by

Then, it can be calculated as where . Similarly, we can obtain as

In addition, the second term is given by

Similar in above, it can be rewritten by

Then, using Gaussian-Chebyshev Quad we can approximate as where . Putting (A.5) and (A.7) into (A.1), the proof is completed.

Data Availability

No data were used to support this study.

Conflicts of Interest

The authors declare that they have no conflicts of interest.

Acknowledgments

This work has been supported by Van Lang University, Ho Chi Minh City, Vietnam, under the Project 1000.

References

M. Coşandal, E. B. Koca, and H. Sari, “NOMA-2000 versus PD-NOMA: an outage probability comparison,” IEEE Communications Letters, vol. 25, no. 2, pp. 427–431, 2021.
View at: Publisher Site | Google Scholar
B. Xu, Z. Xiang, P. Ren, and X. Guo, “Outage performance of downlink full-duplex network-coded cooperative NOMA,” IEEE Wireless Communications Letters, vol. 10, no. 1, pp. 26–29, 2021.
View at: Publisher Site | Google Scholar
M.-S. Van Nguyen, S. Dinh-Thuan Do, S. Al-Rubaye, A. A.-D. Mumtaz, and O. Dobre, “Exploiting impacts of antenna selection and energy harvesting for massive network connectivity,” IEEE Transactions on Communications, vol. 69, no. 11, pp. 7587–7602, 2021.
View at: Google Scholar
D.-T. Do, A. Le, and B. M. Lee, “NOMA in cooperative underlay cognitive radio networks under imperfect SIC,” IEEE Access, vol. 8, pp. 86180–86195, 2020.
View at: Publisher Site | Google Scholar
D.-T. Do, M. -S. V. Nguyen, F. Jameel, R. Jäntti, and I. S. Ansari, “Performance evaluation of relay-aided CR-NOMA for beyond 5G communications,” IEEE Access, vol. 8, pp. 134838–134855, 2020.
View at: Publisher Site | Google Scholar
D.-T. Do, A.-T. Le, Y. Liu, and A. Jamalipour, “User grouping and energy harvesting in UAV-NOMA system with AF/DF relaying,” IEEE Transactions on Vehicular Technology, vol. 70, no. 11, pp. 11855–11868, 2021.
View at: Publisher Site | Google Scholar
F. Zhou, Y. Wu, Y.-C. Liang, Z. Li, Y. Wang, and K.-K. Wong, “State of the art, taxonomy, and open issues on cognitive radio networks with NOMA,” IEEE Wireless Communications, vol. 25, no. 2, pp. 100–108, 2018.
View at: Publisher Site | Google Scholar
J. Choi, “Repetition-based NOMA transmission and its outage probability analysis,” IEEE Transactions on Vehicular Technology, vol. 69, no. 6, pp. 5913–5922, 2020.
View at: Publisher Site | Google Scholar
V. Aswathi and A. V. Babu, “Full/half duplex cooperative NOMA under imperfect successive interference cancellation and channel state estimation errors,” IEEE Access, vol. 7, pp. 179961–179984, 2019.
View at: Publisher Site | Google Scholar
N. Jaiswal and N. Purohit, “Performance of downlink NOMA-enabled vehicular communications over double Rayleigh fading channels,” IET Communications, vol. 14, no. 20, pp. 3652–3660, 2020.
View at: Publisher Site | Google Scholar
Y. Zou, J. Zhu, X. Wang, and L. Hanzo, “A survey on wireless security: technical challenges, recent advances, and future trends,” Proceedings of the IEEE, vol. 104, no. 9, pp. 1727–1765, 2016.
View at: Publisher Site | Google Scholar
Y. Liu, H. H. Chen, and L. Wang, “Physical layer security for next generation wireless networks: theories, technologies, and challenges,” IEEE Communications Surveys & Tutorials, vol. 19, no. 1, pp. 347–376, 2017.
View at: Publisher Site | Google Scholar
Y. Zou, X. Wang, and W. Shen, “Physical-layer security with multiuser scheduling in cognitive radio networks,” IEEE Transactions on Communications, vol. 61, no. 12, pp. 5103–5113, 2013.
View at: Publisher Site | Google Scholar
Y. Zou, X. Li, and Y. C. Liang, “Secrecy outage and diversity analysis of cognitive radio systems,” IEEE Journal on Selected Areas in Communications, vol. 32, no. 11, pp. 2222–2236, 2014.
View at: Publisher Site | Google Scholar
Y. Liu, L. Wang, T. T. Duy, M. Elkashlan, and T. Q. Duong, “Relay selection for security enhancement in cognitive relay networks,” IEEE Wireless Communications Letters, vol. 4, no. 1, pp. 46–49, 2015.
View at: Publisher Site | Google Scholar
A. Al-Nahari, G. Geraci, M. Al-Jamali, M. H. Ahmed, and N. Yang, “Beamforming with artificial noise for secure MISOME cognitive radio transmissions,” IEEE Transactions on Information Forensics and Security, vol. 13, no. 8, pp. 1875–1889, 2018.
View at: Publisher Site | Google Scholar
C. Tang, G. Pan, and T. Li, “Secrecy outage analysis of underlay cognitive radio unit over Nakagami-m fading channels,” IEEE Wireless Communications Letters, vol. 3, no. 6, pp. 609–612, 2014.
View at: Publisher Site | Google Scholar
H. Lei, C. Gao, I. S. Ansari et al., “Secrecy outage performance of transmit antenna selection for MIMO underlay cognitive radio systems over Nakagami-m channels,” IEEE Transactions on Vehicular Technology, vol. 66, no. 3, pp. 2237–2250, 2017.
View at: Publisher Site | Google Scholar
R. Zhao, Y. Yuan, L. Fan, and Y. C. He, “Secrecy performance analysis of cognitive decode-and-forward relay networks in Nakagami- m fading channels,” IEEE Transactions on Communications, vol. 65, no. 2, pp. 549–563, 2017.
View at: Publisher Site | Google Scholar
Z. Xiang, W. Yang, G. Pan, Y. Cai, and Y. Song, “Physical layer security in cognitive radio inspired NOMA network,” IEEE Journal of Selected Topics in Signal Processing, vol. 13, no. 3, pp. 700–714, 2019.
View at: Publisher Site | Google Scholar
B. Zheng, M. Wen, C. X. Wang et al., “Secure NOMA based two-way relay networks using artificial noise and full duplex,” IEEE Journal on Selected Areas in Communications, vol. 36, no. 7, pp. 1426–1440, 2018.
View at: Publisher Site | Google Scholar
L. Lv, Z. Ding, Q. Ni, and J. Chen, “Secure MISO-NOMA transmission with artificial noise,” IEEE Transactions on Vehicular Technology, vol. 67, no. 7, pp. 6700–6705, 2018.
View at: Publisher Site | Google Scholar
J. Chen, L. Yang, and M. S. Alouini, “Physical layer security for cooperative NOMA systems,” IEEE Transactions on Vehicular Technology, vol. 67, no. 5, pp. 4645–4649, 2018.
View at: Publisher Site | Google Scholar
B. He, A. Liu, N. Yang, and V. K. N. Lau, “On the design of secure non-orthogonal multiple access systems,” IEEE Journal on Selected Areas in Communications, vol. 35, no. 10, pp. 2196–2206, 2017.
View at: Publisher Site | Google Scholar
Z. Ding, Z. Zhao, M. Peng, and H. V. Poor, “On the spectral efficiency and security enhancements of NOMA assisted multicast-unicast streaming,” IEEE Transactions on Communications, vol. 65, no. 7, pp. 3151–3163, 2017.
View at: Publisher Site | Google Scholar
Y. Li, M. Jiang, Q. Zhang, Q. Li, and J. Qin, “Secure beamforming in downlink MISO nonorthogonal multiple access systems,” IEEE Transactions on Vehicular Technology, vol. 66, no. 8, pp. 7563–7567, 2017.
View at: Publisher Site | Google Scholar
X. Li, M. Zhao, M. Zeng et al., “Hardware impaired ambient backscatter NOMA systems: reliability and security,” IEEE Transactions on Communications, vol. 69, no. 4, pp. 2723–2736, 2021.
View at: Publisher Site | Google Scholar
N. Zaghdoud, A. B. Mnaouer, H. Boujemaa, and F. Touati, “Secrecy performance of cooperative NOMA system with multiple full-duplex relays against non-colluding/colluding eavesdroppers,” in 2020 IEEE 45th LCN Symposium on Emerging Topics in Networking (LCN Symposium), pp. 70–77, Sydney, Australia, 2020.
View at: Publisher Site | Google Scholar
X. Li, M. Zhao, X. C. Gao et al., “Physical layer security of cooperative NOMA for IoT networks under I/Q imbalance,” IEEE Access, vol. 8, pp. 51189–51199, 2020.
View at: Publisher Site | Google Scholar
W. U. Khan, “Maximizing physical layer security in relay-assisted multicarrier nonorthogonal multiple access transmission,” Internet Technology Letters, vol. 2, no. 2, 2019.
View at: Publisher Site | Google Scholar
M.-S. Van Nguyen and D.-T. Do, “Evaluating secrecy performance of cooperative NOMA networks under existence of relay link and direct link,” International Journal of Communication Systems, vol. 33, no. 6, 2020.
View at: Publisher Site | Google Scholar
L. Lv, H. Jiang, Z. Ding, L. Yang, and J. Chen, “Secrecy-enhancing design for cooperative downlink and uplink NOMA with an untrusted relay,” IEEE Transactions on Communications, vol. 68, no. 3, pp. 1698–1715, 2020.
View at: Publisher Site | Google Scholar
L. Lv, F. Zhou, J. Chen, and N. Al-Dhahir, “Secure cooperative communications with an untrusted relay: a NOMA-inspired jamming and relaying approach,” IEEE Transactions on Information Forensics and Security, vol. 14, no. 12, pp. 3191–3205, 2019.
View at: Publisher Site | Google Scholar
H. Lei, Z. Yang, K. H. Park et al., “Secrecy outage analysis for cooperative NOMA systems with relay selection schemes,” IEEE Transactions on Communications, vol. 67, no. 9, pp. 6282–6298, 2019.
View at: Publisher Site | Google Scholar
H. Lei, Z. Yang, K. Park, I. S. Ansari, G. Pan, and M. Alouini, “On physical layer security of multiple-relay assisted NOMA systems,” in 2019 IEEE International Conference on Communications Workshops (ICC Workshops), Shanghai, China, 2019.
View at: Publisher Site | Google Scholar
C. Yu, H. Ko, X. Peng, W. Xie, and P. Zhu, “Jammer-aided secure communications for cooperative NOMA systems,” IEEE Communications Letters, vol. 23, no. 11, pp. 1935–1939, 2019.
View at: Publisher Site | Google Scholar
D. Wan, M. Wen, F. Ji, H. Yu, and F. Chen, “Non-orthogonal multiple access for cooperative communications: challenges, opportunities, and trends,” IEEE Wireless Communications, vol. 25, no. 2, pp. 109–117, 2018.
View at: Publisher Site | Google Scholar
X. Chen, R. Jia, and D. W. K. Ng, “The application of relay to massive non-orthogonal multiple access,” IEEE Transactions on Communications, vol. 66, no. 11, pp. 5168–5180, 2018.
View at: Publisher Site | Google Scholar
T. N. Nguyen, D. H. Tran, T. V. Chien et al., “Security-reliability trade-off analysis for SWIPT-and AF-based IoT networks with friendly jammers,” 2022, http://arxiv.org/abs/2206.04428.
View at: Google Scholar
V.-D. Phan, T. N. Nguyen, A. V. Le, and M. Voznak, “A study of physical layer security in SWIPT-based decode-and-forward relay networks with dynamic power splitting,” Sensors, vol. 21, no. 17, p. 5692, 2021.
View at: Publisher Site | Google Scholar
T. N. Nguyen, D. H. Tran, V. D. Phan et al., “Throughput enhancement in FD- and SWIPT-enabled IoT networks over nonidentical Rayleigh fading channels,” IEEE Internet of Things Journal, vol. 9, no. 12, pp. 10172–10186, 2022.
View at: Publisher Site | Google Scholar
T. N. Nguyen, T. T. Duy, P. T. Tran, M. Voznak, X. Li, and H. V. Poor, “Partial and full relay selection algorithms for AF multi-relay full-duplex networks with self-energy recycling in non-identically distributed fading channels,” IEEE Transactions on Vehicular Technology, vol. 71, no. 6, pp. 6173–6188, 2022.
View at: Publisher Site | Google Scholar
Y. Liu, Z. Qin, M. Elkashlan, Y. Gao, and L. Hanzo, “Enhancing the physical layer security of non-orthogonal multiple access in large-scale networks,” IEEE Transactions on Wireless Communications, vol. 16, no. 3, pp. 1656–1672, 2017.
View at: Publisher Site | Google Scholar
D.-T. Do and A.-T. Le, “NOMA based cognitive relaying: transceiver hardware impairments, relay selection policies and outage performance comparison,” Computer Communications, vol. 146, pp. 144–154, 2019.
View at: Publisher Site | Google Scholar
I. Krikidis, J. Thompson, S. Mclaughlin, and N. Goertz, “Amplify-and-forward with partial relay selection,” IEEE Communications Letters, vol. 12, no. 4, pp. 235–237, 2008.
View at: Publisher Site | Google Scholar
I. S. Gradshteyn and I. M. Ryzhik, Table of Integrals, Series, and Products, Academic Press, San Diego, CA, 2000.
N. M. S. Do DT and T. A. Hoang, “Exploiting secure performance in power domain--based multiple access: impacts of relay link/direct link and secure analysis,” International Journal of Communication Systems, vol. 32, no. 15, 2019.
View at: Publisher Site | Google Scholar

Copyright

Copyright © 2022 Nhan Duc Nguyen et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

PDF Download Citation

Download other formats

Order printed copies

Views

180

Downloads

326

Citations