In this paper, we analyze the secrecy performance of a dual hop communication system with decode and forward relay (DFR) in the presence of an eavesdropper (EAV), which operates in full duplex mode. The secrecy capacity of the system is enhanced by using a Hybrid scheme of combination of time switching-based relaying (TSR) and power splitting-based relaying (PSR). A novel scheme of assisting the confidential information transmission by simultaneous transmission of jamming signal is presented. Both relay and EAV harvest energy from RF signals by using the Hybrid scheme. The performance of the scheme is evaluated in terms of secrecy outage probability (SOP) under several conditions of network parameters and SNRs of inter node channels. We also compare the results of PSR scheme alone in terms of SOP with Hybrid scheme under our proposed jamming model. MATLAB based simulation of our scheme demonstrates significant reduction of SOP.
In this paper, we analyze the secrecy performance of a dual hop communication system with decode and forward relay (DFR) in the presence of an eavesdropper (EAV), which operates in full duplex mode. The secrecy capacity of the system is enhanced by using a Hybrid scheme of combination of time switching-based relaying (TSR) and power splitting-based relaying (PSR). A novel scheme of assisting the confidential information transmission by simultaneous transmission of jamming signal is presented. Both relay and EAV harvest energy from RF signals by using the Hybrid scheme. The performance of the scheme is evaluated in terms of secrecy outage probability (SOP) under several conditions of network parameters and SNRs of inter node channels. We also compare the results of PSR scheme alone in terms of SOP with Hybrid scheme under our proposed jamming model. MATLAB based simulation of our scheme demonstrates significant reduction of SOP.
In this paper we evaluate the secrecy outage probability (SOP) of an amplify and forward relay (AFR) scheme in presence of a single eavesdropper (EAV). A two hop communication scheme is studied where secrecy is enhanced by transmitting jamming signals from source (S), relay (R) and destination (D). A novel scheme of assisting the confidential information transfer by simultaneous transmission of jamming signal is presented. The source transmit power is appropriately divided for simultaneously transmission of jamming signal and information signal following a power splitting ratio (a). The performance of the scheme is evaluated in terms of secrecy outage probability (SOP) under several conditions of transmission power of source, relay, destination and SNRs of inter node channels. A MATLAB based simulation of our scheme demonstrates significant reduction of SOP.
A two-hop relay network is considered, in which an eavesdropper can overhear the relaying signal. To prevent the eavesdropper from decoding this signal, a destination transmits a jamming noise while a source transmits the data signal to the relay. At the same time, the relay can harvest energy from both the source signal and the jamming noise, and use this harvested energy to forward the received signal to the destination. In such a wireless-powered relay system with cooperative jamming, we propose two adaptive relaying schemes based on power splitting and time switching techniques. In the proposed power splitting-based relaying (PSR) and time switching-based relaying (TSR) schemes, the relay controls the power splitting ratio (p) and time switching ratio (α), respectively, in order to achieve a balance between signal processing and energy harvesting. We find analytically the optimal values of p and α in each scheme to maximize the secrecy capacity under the assumption of high signal-to-noise ratio (SNR). Interestingly, although the eavesdropper's channel state information (CSI) is used in the derivation of the optimal control parameters (p and α), they are shown not to be affected by the eavesdropper's CSI in a high SNR regime. This implies that the proposed schemes can be effective even for practical environments where there is no eavesdropper's CSI. Furthermore, simulation results show that they well coincide with the exact solutions in practical environments even though the closed-form solutions are obtained with a high SNR assumption. Moreover, the comparisons of PSR and TSR in various scenarios show that the two relaying schemes have complementary performances depending on the network conditions. Specifically, PSR achieves greater secrecy capacity than TSR when the channel condition is unfavorable to the eavesdropper for wiretapping.
This paper studies the secrecy performance of an energy-harvesting relaying system in the presence of a dualuse source node and an eavesdropper.Specifically, the source has dual roles in the dual-hop communication: 1) to transmit confidential information in the first hop; 2) to generate jamming signal to interfere the eavesdropper in the second hop.Moreover, the multi-antenna relay deploys a power-splitting harvesting scheme to coordinate the information receiving and energy harvesting, and adopts maximal ratio combining technique to process the multiple copies of signals.Considering decode-andforward protocol and transmit antenna selection scheme, we derive an analytical expression for secrecy outage probability, and perform Monte Carlo simulation to validate the analysis.Analytical results show that the SOP performance with the dualuse source node can be effectively improved when the relaydestination channel does not have absolute advantage over the relay-eavesdropper channel.
This article studies a secure communication of a simultaneous wireless information and power transfer system in which an energy-constrained untrusted relay, which harvests energy from the wireless signals, helps the communication between the source and destination and is able to decode the source’s confidential signal. Additionally, the source’s confidential signal is also overheard by a passive eavesdropper. To create positive secrecy capacity, a destination-assisted jamming signal that is completely cancelled at the destination is adopted. Moreover, the jamming signal is also exploited as an additional energy source. To evaluate the secrecy performance, analytical expressions for the secrecy outage probability (SOP) and the average secrecy capacity are derived. Moreover, a high-power approximation for the SOP is presented. The accuracy of the analytical results is verified by Monte Carlo simulations. Numerical results provide valuable insights into the effect of various system parameters, such as the energy-harvesting efficiency, secrecy rate threshold, power-splitting ratio, transmit powers, and locations of the relay and eavesdropper, on the secrecy performance.
In this article, we investigated the secrecy performance of a three-hop relay network system with Power Splitting (PS) and Energy Harvesting (EH). In the presence of one eavesdropper, a signal is transferred from source to destination with the help of a relay. The source signal transmits in full-duplex (FD) mood, jamming the relay transfer signals to the destination. The relay and source employ Time Switching (TS) and Energy Harvesting (EH) techniques to obtain the power from the power beacon. In this study, we compared the Secrecy Rate of two Cooperative Schemes, Amplify and Forward (AF) and Decode and Forward (DF), for both designed systems with the established EH and PS system. The Secrecy Rate was improved by 50.5% in the AF scheme and by 44.2% in the DF scheme between the relay and eavesdropper at 40 m apart for the proposed system in EH and PS. This simulation was performed using the Monto Carlo method in MATLAB.
In this paper, we consider a multi-node-assisted two-hop cooperative network, where an energy constrained source (S) aims to establish secure communications with a legitimate user in the presence of an eavesdropper. The cooperative nodes simultaneously assist the transmission from base station to legitimate user. Each cooperative node applies power splitting protocol to coordinate the received signal energy for information decoding and energy harvesting. The power splitting ratios at multi-node are formulated based on decode-and-forward (DF) relaying protocols. Depending on the available channel state information (CSI) at the source, we propose two different jamming schemes for secrecy performance enhancement. An optimal node is selected as a jammer to interfere the eavesdropper or a relay to forward the information to legitimate user. we evaluate the network performance based on secrecy outage probability (SOP). In addition, simple and accurate approximations are obtained at different transmission speed thresholds. Furthermore, numerical results reveal that there exist unique splitting ratios and harvesting efficiency that minimize the SOP.