scholarly journals Secrecy Performance of Underlay Cooperative Cognitive Network Using Non-Orthogonal Multiple Access with Opportunistic Relay Selection

Symmetry ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 385 ◽  
Author(s):  
Tan-Phuoc Huynh ◽  
Pham Ngoc Son ◽  
Miroslav Voznak
Keyword(s):  
Fading Channels ◽  
Relay Selection ◽  
Multiple Access ◽  
Source Node ◽  
Secrecy Outage Probability ◽  
Decode And Forward ◽  
Cognitive Network ◽  
Best Relay Selection ◽  
Secrecy Outage ◽  
Outage Probabilities

In this paper, an underlay cooperative cognitive network using a non-orthogonal multiple access (UCCN-NOMA) system is investigated, in which the intermediate multiple relays help to decode and forward two signals x 1 and x 2 from a source node to two users D1 and D2, respectively, under wiretapping of an eavesdropper (E). We study the best relay selection strategies by three types of relay selection criteria: the first and second best relay selection is based on the maximum channel gain of the links R i -D 1 , R i -D2, respectively; the third one is to ensure a minimum value of the channel gains from the R i -E link. We analyze and evaluate the secrecy performances of the transmissions x 1 and x 2 from the source node to the destination nodes D1, D2, respectively, in the proposed UCCN-NOMA system in terms of the secrecy outage probabilities (SOPs) over Rayleigh fading channels. Simulation and analysis results are presented as follows. The results of the (sum) secrecy outage probability show that proposed scheme can realize the maximal diversity gain. The security of the system is very good when eavesdropper node E is far from the source and cooperative relay. Finally, the theoretical analyses are verified by performing Monte Carlo simulations.

scholarly journals Partial Relay Selection for Secure Cooperative NOMA Networks

2021 ◽  
Author(s):  
Wided Hadj Alouane
Keyword(s):  
Fading Channels ◽  
Relay Selection ◽  
Signal To Noise Ratio ◽  
Secrecy Outage Probability ◽  
Amplify And Forward ◽  
Decode And Forward ◽  
Partial Relay Selection ◽  
Asymptotic Expressions ◽  
Selection For ◽  
Secrecy Outage

Abstract In this paper, we investigate physical layer security of multi-relay non-orthogonal multiple access (NOMA) networks with partial relay selection considering decode-and-forward (DF) and amplify-and-forward (AF) protocols. We propose a partial relay scheme aiming to select the best relay based on the highest signal-to-noise-ratio (SNR) of the first link. We derive new exact and asymptotic expressions for strictly positive secrecy capacity (SPSC) and secrecy outage probability (SOP) considering Rayleigh fading channels. Numerical results demonstrate that AF and DF provide almost a similar secrecy performance. Moreover, they prove that partial relay selection improves SPSC and reduces SOP when the relay-cluster is closer to the legitimate receiver.

Relay Selection-aware Non-orthogonal Multiple Access Networks: Direct and Relaying Mode

2020 ◽  
Vol 13 (3) ◽  
pp. 348-354
Author(s):  
Dinh-Thuan Do ◽  
Minh-Sang V. Nguyen
Keyword(s):  
Relay Selection ◽  
Multiple Access ◽  
Decode And Forward ◽  
Selection Scheme ◽  
Fixed Power ◽  
Transmission Quality ◽  
Improved Performance ◽  
Outage Probabilities ◽  
Future Work ◽  
The Impact

Objective: In this paper, Decode-and-Forward (DF) mode is deployed in the Relay Selection (RS) scheme to provide better performance in cooperative downlink Non-orthogonal Multiple Access (NOMA) networks. In particular, evaluation regarding the impact of the number of multiple relays on outage performance is presented. Methods: As main parameter affecting cooperative NOMA performance, we consider the scenario of the fixed power allocations and the varying number of relays. In addition, the expressions of outage probabilities are the main metric to examine separated NOMA users. By matching related results between simulation and analytical methods, the exactness of derived formula can be verified. Results: The intuitive main results show that in such cooperative NOMA networks, the higher the number of relays equipped, the better the system performance can be achieved. Conclusion: DF mode is confirmed as a reasonable selection scheme to improve the transmission quality in NOMA. In future work, we will introduce new relay selections to achieve improved performance.

scholarly journals Physical Layer Security in Multi-hop Cooperative Wireless Relaying

2021 ◽  
Author(s):  
Sajad Hatamnia ◽  
Mahdi Morafah ◽  
Bill Lin
Keyword(s):  
Relay Selection ◽  
Practical Interest ◽  
Physical Layer ◽  
Link Quality ◽  
Secrecy Outage Probability ◽  
Source Information ◽  
Decode And Forward ◽  
Special Cases ◽  
Secrecy Outage ◽  
Combine Information

<div> <div> <div> <p>In the last decade, multi-hop cooperation has evolved bringing several advantages including coverage improvement, more reliability of wireless links, and power consumption reduction. Still, its application has raised several challenges, such as the need for secure transmission at each hop, algorithms to perform relay selection and the accurate models to facilitate performance analysis. This paper addresses the problem of physical layer (PHY) security in a multi-hop wireless cooperative network, where communication at each hop is assisted by multiple relays forming a cluster, each cluster being surrounded by multiple eavesdroppers which together may tap transmissions from both the source and the relays. The main focus of the study is on analyzing the benefits of various relay selection schemes for protecting the source-destination transmission against the eavesdroppers, which can collude and combine information via diversity combining techniques. To be specific, four relay selection schemes, which differ in the way they employ available measures link quality, are considered to deliver the source information to the destination via a decode-and-forward (DF) strategy. To evaluate the security performance of the multi-hop cooperative link in the presence of colluding eavesdroppers, we derive novel closed-form analytical expressions for the secrecy outage probability (SOP) with consideration of special cases of practical interest. </p> </div> </div> </div>

scholarly journals Secrecy Performance Analysis of Half/Full Duplex AF/DF Relaying in NOMA Systems Over κ - μ Fading Channels

2021 ◽  
Author(s):  
Nesrine Zaghdoud ◽  
Adel Ben Mnaouer ◽  
Hatem Boujemaa ◽  
Farid Touati
Keyword(s):  
Fading Channels ◽  
Signal To Noise Ratio ◽  
Multipath Fading ◽  
Full Duplex ◽  
High Signal ◽  
Secrecy Outage Probability ◽  
Amplify And Forward ◽  
Decode And Forward ◽  
Special Cases ◽  
Secrecy Outage

Abstract Although the progress in understanding 5G and beyond techniques such as Non-Orthogonal Multiple Access (NOMA) and full-duplex techniques has been overwhelming, still analyzing the security aspects of such systems under different scenarios and settings is an important concern that needs further exploration. In particular, when considering fading in wiretap channels and scenarios, achieving secrecy has posed many challenges. In this context, we propose to study the physical layer security (PLS) of cooperative NOMA (C-NOMA) system using the general fading distribution κ - μ. This distribution facilitates mainly the effect of light-of-sight as well as multipath fading. It also includes multiple distributions as special cases like: Rayleigh, Rice, Nakagami-m which help to understand the comportment of C-NOMA systems under different fading parameters. The use of Half-Duplex and Full-Duplex communication is also investigated for both Amplify-and-forward (AF) and Decode-and-Forward (DF) relaying protocols. To characterize the secrecy performance of the proposed C-NOMA systems, closed form expressions of the Secrecy Outage Probability (SOP) and the Strictly Positive Secrcey Capacity (SPSC) metrics for the strong and weak users are given for high signal-to-noise ratio (SNR) due to the intractable nature of the exact expressions. Based on the analytical analysis, numerical and simulation results are given under different network parameters.

scholarly journals Secrecy Outage Probability of a NOMA Scheme and Impact Imperfect Channel State Information in Underlay Cooperative Cognitive Networks

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 895
Author(s):  
Tan-Phuoc Huynh ◽  
Duy-Hung Ha ◽  
Cong Truong Thanh ◽  
Peppino Fazio ◽  
Miroslav Voznak
Keyword(s):  
Fading Channels ◽  
Channel State Information ◽  
Cognitive Networks ◽  
Source Node ◽  
Secrecy Outage Probability ◽  
Imperfect Channel State Information ◽  
Channel State ◽  
State Information ◽  
Secrecy Outage ◽  
The Impact

Security performance and the impact of imperfect channel state information (CSI) in underlay cooperative cognitive networks (UCCN) is investigated in this paper. In the proposed scheme, relay R uses non-orthogonal multiple access (NOMA) technology to transfer messages e 1 , e 2 from the source node S to User 1 (U1) and User 2 (U2), respectively. An eavesdropper (E) is also proposed to wiretap the messages of U1 and U2. The transmission’s security performance in the proposed system was analyzed and performed over Rayleigh fading channels. Through numerical analysis, the results showed that the proposed system’s secrecy performance became more efficient when the eavesdropper node E was farther away from the source node S and the intermediate cooperative relay R. The secrecy performance of U1 was also compared to the secrecy performance of U2. Finally, the simulation results matched the Monte Carlo simulations well.

scholarly journals Physical Layer Security in Multi-hop Cooperative Wireless Relaying

2021 ◽  
Author(s):  
Sajad Hatamnia ◽  
Mahdi Morafah ◽  
Bill Lin
Keyword(s):  
Relay Selection ◽  
Practical Interest ◽  
Physical Layer ◽  
Link Quality ◽  
Secrecy Outage Probability ◽  
Source Information ◽  
Decode And Forward ◽  
Special Cases ◽  
Secrecy Outage ◽  
Combine Information

<div> <div> <div> <p>In the last decade, multi-hop cooperation has evolved bringing several advantages including coverage improvement, more reliability of wireless links, and power consumption reduction. Still, its application has raised several challenges, such as the need for secure transmission at each hop, algorithms to perform relay selection and the accurate models to facilitate performance analysis. This paper addresses the problem of physical layer (PHY) security in a multi-hop wireless cooperative network, where communication at each hop is assisted by multiple relays forming a cluster, each cluster being surrounded by multiple eavesdroppers which together may tap transmissions from both the source and the relays. The main focus of the study is on analyzing the benefits of various relay selection schemes for protecting the source-destination transmission against the eavesdroppers, which can collude and combine information via diversity combining techniques. To be specific, four relay selection schemes, which differ in the way they employ available measures link quality, are considered to deliver the source information to the destination via a decode-and-forward (DF) strategy. To evaluate the security performance of the multi-hop cooperative link in the presence of colluding eavesdroppers, we derive novel closed-form analytical expressions for the secrecy outage probability (SOP) with consideration of special cases of practical interest. </p> </div> </div> </div>

Exact Outage Probability Analysis for Selection Decode-and-Forward Cooperation Systems

2011 ◽  
Vol 341-342 ◽  
pp. 509-513
Author(s):  
Yu Long Zou ◽  
Yu Dong Yao
Keyword(s):  
Outage Probability ◽  
Fading Channels ◽  
Signal To Noise Ratio ◽  
Source Node ◽  
Closed Form Expression ◽  
Decode And Forward ◽  
Full Diversity ◽  
Best Relay Selection ◽  
The One ◽  
Outage Analysis

In this paper, we present a selection decode-and- forward (S-DF) cooperation scheme where only the “best” relay, which is selected as the one who can decode correctly its received signal from source node and can achieve the highest instantaneous signal-to-noise ratio (SNR) at the destination, participates in relaying the source’s signal. We derive a novel exact closed-form expression of outage probability for the S-DF scheme over Rayleigh fading channels, based on which an asymptotic outage analysis is further presented in high SNR regime, showing that given M potential relays, M+1 diversity order is achieved by source node. Consequently, the proposed S-DF scheme with the best relay selection can achieve the full diversity at the expense of just two channels only regardless of the number of candidate relays.

Outage Analysis of Dual-hop Cognitive Networks with Relay Selection over Nakagami-m Fading Environment

Frequenz ◽  
2014 ◽  
Vol 68 (9-10) ◽  
Author(s):  
Zongsheng Zhang ◽  
Xurong Pi
Keyword(s):  
Outage Probability ◽  
Closed Form ◽  
Fading Channels ◽  
Relay Selection ◽  
Primary User ◽  
Cognitive Networks ◽  
Decode And Forward ◽  
Cognitive Approach ◽  
Full Diversity ◽  
Best Relay Selection

AbstractIn this paper, we investigate the outage performance of decode-and-forward cognitive relay networks for Nakagami-m fading channels, with considering both best relay selection and interference constraints. Focusing on the relay selection and making use of the underlay cognitive approach, an exact closed-form outage probability expression is derived in an independent, non-identical distributed Nakagami-m environment. The closed-form outage probability provides an efficient means to evaluate the effects of the maximum allowable interference power, number of cognitive relays, and channel conditions between the primary user and cognitive users. Finally, we present numerical results to validate the theory analysis. Moreover, from the simulation results, we obtain that the system can obtain the full diversity.

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