The simultaneous wireless information and power transfer (SWIPT) technology is recently used to sustain the lifetime of energy-constrained relay nodes in wireless cooperative networks. An example to achieve this technology is the hybridized power-time splitting-based relaying (HPTSR) protocol. However, the information security aspect of wireless cooperative networks is important and needs adequate attention. In this paper, we perform the secrecy analysis of a SWIPT-enabled cooperative network with source–relay link-based decode-and-forward HPTSR protocol, which can enhance the operational lifetime of the relay nodes and the secrecy performance of the entire cooperative network. Specifically, we examine the secrecy performance of the considered network by deriving the analytical expressions for the near-optimal power splitting factor, secrecy outage probability, and secure energy efficiency of the system. All analytical results are confirmed by numerical simulations. Our results show that the SWIPT-enabled cooperative network outperforms the conventional relaying scheme-based network presented in literature at relatively high signal-to-noise ratios.
The simultaneous wireless information and power transfer (SWIPT) technology is recently used to sustain the lifetime of energy-constrained relay nodes in wireless cooperative networks. An example to achieve this technology is the hybridized power-time splitting-based relaying (HPTSR) protocol. However, the information security aspect of wireless cooperative networks is important and needs adequate attention. In this paper, we perform the secrecy analysis of a SWIPT-enabled cooperative network with source–relay link-based decode-and-forward HPTSR protocol, which can enhance the operational lifetime of the relay nodes and the secrecy performance of the entire cooperative network. Specifically, we examine the secrecy performance of the considered network by deriving the analytical expressions for the near-optimal power splitting factor, secrecy outage probability, and secure energy efficiency of the system. All analytical results are confirmed by numerical simulations. Our results show that the SWIPT-enabled cooperative network outperforms the conventional relaying scheme-based network presented in literature at relatively high signal-to-noise ratios.
In this paper, the secrecy outage performance of a three-node amplify-and-forward relay network with an untrustworthy relay is investigated. To enable a secure transmission, we consider a destination-based jamming technique to prevent the relay from successfully decoding the secret messages between the source and the destination. In addition, the relay is assumed to be an energy-constrained device, thus being first energized by the source in order to be able to retransmit the information to the destination. In doing so, a time switching-based simultaneous wireless information and power transfer scheme is used. A closed-form asymptotic expression for the secrecy outage probability is derived in order to obtain a tight approximation at medium-to-high signal-to-noise ratio. The accuracy of the performed analysis is corroborated by Monte Carlo simulations through different illustrative cases. Numerical results show the impact of key system parameters on the secrecy performance, such as the time allocation factor between the energy harvesting and information transmission phases, the power allocation factor between source and destination for cooperative jamming, and the relay position, so as to provide insights on the design criteria for energy efficient and secure networks.
Physical layer security (PLS) with radio frequency (RF) energy harvesting (EH) in wireless sensor networks has received significant interest as a technology for secure information transmission and prolonging the network lifetime, as well as improving energy efficiency. This article investigates PLS for a simultaneous wireless information and power transfer (SWIPT) cooperative network, which consists of multiple sensor sources, one EH relay (R), and one destination (D) in the presence of one eavesdropper (E). Furthermore, a low-complexity, suboptimal, yet efficient sensor source selection scheme is proposed. Specifically, one sensor source is chosen to transmit information to the relay and destination such that it obtains the best channel from sensor sources to the relay. Then, by considering two relaying strategies, termed the direct link plus static power splitting-based relaying (SPSR) and direct link plus optimal dynamic power splitting-based relaying (ODPSR), the performance analysis in terms of intercept probability (IP) and outage probability (OP) is carried out for each one. Notably, the eavesdropper and destination utilize maximal ratio combining (MRC) to incorporate the received signals from the selected sensor source and the relay, which poses new challenges in obtaining the analytical expressions. In this context, we derive analytical expressions for the OP (for SPSR and ODPSR) at the destination and the IP (for SPSR) at the eavesdropper by adopting the series representation of the modified Bessel function. Finally, Monte Carlo simulations are conducted to validate the theoretical analysis and the proposed schemes’ effectiveness. Simulation results show the superiority of our scheme compared to the benchmarks.
Simultaneous wireless information and power transfer (SWIPT) is a major breakthrough in the field of low-power wireless information transmissions. In this paper, the secrecy performance of the SWIPT-enabled relay network with full-duplex destination-aided jamming is assessed, where both the power-splitting (PS) and time-switching (TS) schemes at the relay are considered with the linear and nonlinear energy harvesting models. The relay harvests energy from the confidential signal and artificial noise sent by the source and destination, respectively, and forwards the amplified signal to the destination, in the presence of an eavesdropper. The analytical closed-form expressions of the connection outage probability (COP), secrecy outage probability (SOP), and transmission outage probability (TOP) for PS- and TS-based schemes are derived, and the closed-form expression of the lower bound of ergodic secrecy capacity (ESC) is calculated. The asymptotic-form expressions of the COP, SOP, TOP, and ESC are further analyzed to capture the valuable information in the high SNR regime. Numerical results verify the correctness of analytical results, reveal the effects of the PS/TS ratio, and transmit the signal-to-noise ratio on secrecy performance.
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.
In Cooperative Networks based on simultaneous wireless information and power transfer (SWIPT), relay nodes collect the energy of radio signals received from source node and transmit the information of source nodes to destination nodes, which not only prolongs the service life of energy-constrained nodes, but also improves the ability of long-distance transmission of information. Due to the openness of energy harvesting, there may be eavesdropping users with malicious decoding. In order to study the security performance of the Cooperative Networks based on SWIPT, this paper mainly studies the physical layer security performance of this network, derives and simulates the expression of system security outage probability and throughput. The simulation results show that the system security performance is mainly influenced by time allocation parameter of SWIPT and decreases with the increase of target rate.
In this paper, we study the physical layer security for simultaneous wireless information and power transfer (SWIPT)-based half-duplex (HD) decode-and-forward relaying system. We consider a system model including one transmitter that tries to transmit information to one receiver under the help of multiple relay users and in the presence of one eavesdropper that attempts to overhear the confidential information. More specifically, to investigate the secrecy performance, we derive closed-form expressions of outage probability (OP) and secrecy outage probability for dynamic power splitting-based relaying (DPSBR) and static power splitting-based relaying (SPSBR) schemes. Moreover, the lower bound of secrecy outage probability is obtained when the source's transmit power goes to infinity. The Monte Carlo simulations are given to corroborate the correctness of our mathematical analysis. It is observed from simulation results that the proposed DPSBR scheme outperforms the SPSBR-based schemes in terms of OP and SOP under the impact of different parameters on system performance.