Secrecy Performance of Cooperative NOMA System with Multiple Full-Duplex Relays against Non-Colluding/Colluding Eavesdroppers

In 5G and beyond wireless communication net-works, non-orthogonal multiple access (NOMA) and Full-Duplex (FD) techniques are considered as promising key techniques. However, the secrecy in NOMA systems has proven to be quite challenging, especially in the presence of multiple eavesdroppers. For this purpose and using the potential of cooperative and FD communication, we investigate the secrecy performance of dual-hop FD Amplify-and-Forward NOMA system. Based on the channel state information of the first hop, partial relay selection (PRS) is performed to determine the best relay. The secrecy outage behaviour of the considered system is studied through deriving closed-form expressions of the secrecy outage probability (SOP) metric for both strong and weak NOMA users under the presence of multiple eavesdroppers in colluding and non-colluding wiretapping scenarios. Numerical results are also provided to verify the derived analytical results.Scopu

Secure two-user AF relaying networks using cooperative jamming

In this paper, we investigate secure two-user AF relaying networks based on a destination assisted cooperative jamming (DACJ). We consider two sources, one destination, one eavesdropper and multiple amplify-and-forwards (AF) relays. In the first time slot, each source broadcasts the information signal to the relays. In order to protect the source message from being eavesdropped, the destination simultaneously transmits a jamming signal to each relay. The selected relay amplifies and forwards the combined signal to the destination and eavesdropper. We introduce reactive relay selection and power allocation to decrease the power consumption. Closed-form expressions for lower bound of ergodic secrecy capacity (ESC) are provided. Numerical results are presented to verify the exactness of the proposed mathematical analysis. ? 2018 IEEE.This publication was made possible by NPRP grant # 8-1781-2-735 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors

Secrecy Performance Analysis of Cooperative NOMA system with multiple DF Relays

In this paper, we derive the Secrecy Outage Probability (SOP) and Strictly Positive Secrecy Capacity (SPSC) of cooperative Non Orthogonal Multiple Access (NOMA) in the presence of K Decode and Forward (DF) relays and Rayleigh fading channels. We also optimize the powers allocated to far and near users to maximize the SPSC or minimize the SOP. Our results are valid for any number of relays with arbitrary positions.Scopu

Multihop transmission strategy using dijkstra algorithm to improve energy efficiency in WSNs

Thanks to the development in the wireless communication technologies and the microelectronics domain, Wireless Sensor Networks (WSNs) are more and more omnipresent. The most important challenge of WSN is how to extend its lifetime. For long distance communication, using one hop transmission causes the dissipation of a lot of energy. To avoid this dissipation, an energy-efficient multihop transmission strategy based on Dijkstra algorithm is proposed in this paper. We consider a WSN organized into clusters, each cluster is composed of N sensor nodes classified as follows: source node, cluster head (CH) node as the destination, group of active nodes and group of sleeping nodes. The selection of CH node is based on the position of nodes within the cluster and their residual energy. Then, the CH groups the remaining nodes into active or sleeping nodes according to a reference distance. We suppose that the transmitting symbol is correctly received only if the Signal-to-Noise Ratio (SNR) at the receiver is above a threshold γth. Our main objective is to define a new transmission technique minimizing the power consumption using multihop communication. The selected relays which cooperate to aid the source-destination communication are those offering the least transmit power while maintaining SNR equal to the threshold γth. We use Dijkstra algorithm to select the reliable relays. Simulations results demonstrate that the proposed transmission technique can reduce enormously the power consumption.Scopu

Energy-Efficient Transmission Technique based on Dijkstra Algorithm for decreasing energy consumption in WSNs

In this paper, we propose an energy-efficient multihop transmission technique for Wireless Sensor Networks (WSN) based on Dijkstra algorithm. We consider a WSN composed of N sensor nodes. Firstly, we group the sensor nodes into clusters according to their placement in the monitoring area, then we organize the nodes within each cluster by electing the appropriate node as cluster head and classifying the remaining nodes into active nodes and sleeping nodes. Then, we select the set of reliable relays which cooperate to forward data with the least transmit power. Our proposed relay selection algorithm is based on Dijkstra algorithm. The main contribution of the paper is to define a new transmission strategy that improves the results of our previous work proposed in [?] by better minimizing power consumption. Therefore, the proposed transmission technique can improve significantly the reduction of power consumption compared to the previous transmission technique. Simulations results prove that the new transmission technique based on Dijkstra algorithm increases the energy savings to prolong the network lifetime.This publication was made possible by NPRP grant #10-0102-170094 from the Qatar National Research Fund (a member of Qatar Foundation).Scopu

Secure Performance of AF and DF Relaying in Cooperative Noma Systems

In this paper, we study the secrecy outage probability (SOP)and the strictly positive secrecy capacity (SPSC)of cooperative non-orthogonal multiple access (NOMA)system with a single antenna over Rayleigh fading channel in which there are a source, a relay node, two destinations and one eavesdropper. The relay adopts amplify-and-forward (AF)and decode-and-forward (DF)relaying schemes. The SOP and SPSC performance are analyzed to evaluate the level of security granted to legitimate users for both AF and DF protocols. The effects of the optimal power allocation value on system performance are also discussed and provided through numerical results.This publication was made possible by NPRP grant #10-0102-170094 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors.Scopu

Secrecy performance analysis of half/full duplex AF/DF relaying in NOMA systems over κ−μ fading channels

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. The results show, for low eavesdropper SNR, the positive effect of fading on the secrecy of the NOMA system. Whereas, fading deteriorates more the system secrecy with high eavesdropper SNR. We also deduce that FD relaying gives better secrecy to the weak user. While, more secrecy is granted to the strong user when using HD relayingScopu

A Clustering Routing based on Dijkstra Algorithm for WSNs

Wireless Sensor Networks (WSNs) have witnessed a growing interest in the last two decades owing to its various advantages. Thus, in a big WSN, using one hop transmission, as in LEACH algorithm, causes loss of a lot of energy. To mitigate this loss, a new Clustering Routing based on Dijkstra Algorithm (C.R.D.A) is proposed in this paper. Our main objective in the proposed C.R.D.A is to define a new clustering routing algorithm allowing to reduce power consumption. Therefore, we used a game theory model to find the optimal placement of the sink node. This last searches the best number of clusters using ELBOW method and divides the network into k-{opt} clusters using K-means clustering algorithm. Then, it elects the cluster head of each cluster based on two criteria: the distance to the cluster centroid and the residual energy of nodes. Dijkstra algorithm is applied to select the set of reliable relays which offer the least transmit power to route data inter and intra clusters. The performance of our proposed algorithm is compared to LEACH algorithm. Simulations results demonstrate that the proposed C.R.D.A minimizes significantly the power consumption than LEACH algorithm and consequently prolong the lifetime of WSN.This publication was made possible by NPRP grant #10-0102-170094 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors.Scopu

Impact of outdated CSI on the secrecy performance of dual-hop networks using cooperative jamming

This paper studies the problem of secure dual-hop AF network in the presence of eavesdropper. We study the secrecy performance of partial relay selection with outdated channel state information (CSI). We propose a system secrecy where two sources and destination simultaneously transmit the legitimate and the jamming signal respectively. The selected relay forwards the combined signal to the legitimate receiver and the eavesdropper. We derive a closed-form expression for lower bound on the ergodic secrecy capacity (ESC) under different assumptions of the eavesdropper channel gains. We verify that the system performance is degraded as the correlation coefficient decreases. Simulation results are considered to verify the exactness of the proposed mathematical analysis. - 2019 IEEE.1This publication was made possible by NPRP grant # 10-0102-170094 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors.Scopu

Secure half-duplex dual-hop AF relaying networks with partial relay selection

In this paper, we focus on the half-duplex (HD) relaying with partial relay selection (PRS) scheme using destination-assisted jamming (DAJ). We consider one source (S), one destination (D), one passive eavesdropper and multiple amplify-and-forward (AF) relays. The relay node is selected based on the best instantaneous signal-to-noise ratio (SNR) of the first hop. Closed-form expressions for lower-bound of ergodic secrecy capacity (ESC) and secrecy outage probability (SOP) are derived over independent and identically distributed (i.i.d.) Rayleigh fading environment. Moreover, we present a comparison between the proposed system and the secure AF relaying system with reactive relay selection (RRS). In the RRS, the relay is chosen based on the best SNR of the second hop. Simulation results are presented to verify the exactness of our proposed mathematical analysis. - 2019 IEEE.1This publication was made possible by NPRP grant # 10-0102-170094 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors.Scopu