This work investigates the secure transmission in the wireless information and power transfer system where a source node communicates with a wireless-powered full-duplex destination node in the presence of a passive eavesdropper. In particular, we propose such a two-phase time-sharing (TS) secure communication protocol: in the first phase, energy harvesting is conducted from the source node to the destination node, while in the second phase, the source node transmits information-bearing signal under the protection of artificial noise sent from the destination node. It is worth to mention that the energy of this artificial noise at the destination node is converted from the harvested energy in the first phase and self-interference exists at the destination in the second phase. We derive the closed-form expressions for the connection outage probability (COP), the secrecy outage probability (SOP) and the transmission outage probability (TOP), based on which the secrecy throughput is formulated. Further, we determine the optimal time allocation factor and the optimal codeword transmission rate to maximize the secrecy throughput with dual outage constraints. Finally, numerical results verifies our results and exams the effect of the time allocation factor and the codeword transmission rate on the performance.
This work investigates the secure transmission in the wireless information and power transfer system where a source node communicates with a wireless-powered full-duplex destination node in the presence of a passive eavesdropper. In particular, we propose such a two-phase time-sharing (TS) secure communication protocol: in the first phase, energy harvesting is conducted from the source node to the destination node, while in the second phase, the source node transmits information-bearing signal under the protection of artificial noise sent from the destination node. It is worth to mention that the energy of this artificial noise at the destination node is converted from the harvested energy in the first phase and self-interference exists at the destination in the second phase. We derive the closed-form expressions for the connection outage probability (COP), the secrecy outage probability (SOP) and the transmission outage probability (TOP), based on which the secrecy throughput is formulated. Further, we determine the optimal time allocation factor and the optimal codeword transmission rate to maximize the secrecy throughput with dual outage constraints. Finally, numerical results verifies our results and exams the effect of the time allocation factor and the codeword transmission rate on the performance.
This paper investigates the secure transmission in simultaneous wireless information and power transfer (SWIPT) system, where a source node communicates with a wireless‐powered full duplex destination node in the presence of a passive eavesdropping node. To take advantage of the benefits from SWIPT and full duplex techniques, we propose a two‐phase time‐sharing protocol: the destination node harvests energy form the source node in the first phase, while the information‐bearing signal is transmitted under the protection of artificial noise sent from the destination node in the second phase. The transmit power of the artificial noise is converted from the harvested energy and self‐interference exists at the destination. We derive the closed‐form expressions for the connection outage probability (COP), the secrecy outage probability (SOP) and the transmission outage probability (TOP), based on which the secrecy energy efficiency (SEE) is formulated. Furthermore, we determine the optimal time allocation factor and transmission power that maximize the SEE while satisfying the COP and SOP constraints. Finally, numerical results verify our analytical results and show that there are tradeoffs among security, reliability and energy efficiency. When the residual loopback interference is mitigated under some certain level, our proposed optimization scheme can significantly boost the SEE.
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.
This paper focuses on information security in an energy harvesting relay system, in which confidential signals are transmitted from a source node to its desired destination with the assistance of one full-duplex (FD) relay. To empower simultaneous wireless information and power transfer, the time-switching (TS) protocol is embraced and the energy-limited FD relay node is powered by energy signals emitted by the source node. With the obtained statistical eavesdropper channel state information (CSI), the ergodic secrecy rate and its approximate expression are derived. As the objective is maximizing the ergodic secrecy rate performance, source beamformers, TS coefficient and the power control factor at FD relay are jointly optimized. To tackle the framed non-convex problem, an alternative method is hence proposed, and closed-form solutions for beamformers, TS coefficient and power control factor are derived iteratively. Besides, the convergence of our proposed algorithm can be guaranteed and is also theoretically proved. Simulation results demonstrate that our iterative algorithm is effective and improves the system secrecy rate considerably.
The simultaneous wireless information and power transfer (SWIPT) has recently attracted much attention since both information and energy are integrated within radio frequency signals, which is considered to be one of the most important technologies for future networks. However, security becomes one of the most critical issues in SWIPT networks due to its broadcasting features over wireless media and the transferring requirements for strong signal strength. To improve the security of SWIPT networks, in this paper, a SWIPT system enabled by full-duplex (FD) jamming is proposed, where an FD energy-limited receiver with the power splitting (PS) structure, powered by a transmitter, generates jamming signals. Both linear and nonlinear energy harvesting (EH) models are considered. To evaluate the secrecy throughput (ST) of the system, we derive the closed-form connection outage probability and secrecy outage probability for the proposed PS-based scheme in the delay-constrained transmission (DCT) mode. The ST is maximized by optimizing the PS ratio based on the asymptotic cases of the high signal-to-noise ratio as well as the perfect self-interference cancellation (SIC). Besides, the exact integral forms of the ergodic secrecy capacity and their closed-form lower bounds are presented for both the PS-based and the time switching (TS)-based schemes in the delay-tolerant transmission (DTT) mode. Simulation results suggest that the PS-based scheme outperforms the TS-based scheme for the DTT mode. For the DCT mode, the PS-based scheme can achieve better performance than the TS-based scheme only in low target communication rate, small PS/TS ratio, high transmit power, and weak path loss. Meanwhile, given a tolerable amount of SIC, the ST obtained in the linear EH model is higher than that achieved in the nonlinear EH model.
In this paper, we investigate the secrecy performance of energy-constrained wireless-powered networks with considering the passive eavesdropping scenario, where the simultaneous wireless information and power transfer-based full-duplex self-jamming (SWIPT-FDSJ) scheme is developed. The maximal ratio transmission protocol is applied at the multi-antenna source such that the wireless signals are designated to the destination directly. Besides, the energy harvesting and full-duplex self-jamming operations are adopted at the energy-constrained destination to prolong its lifetime as well as to confuse the eavesdropper. Specifically, the exact and asymptotic closed-form expressions of the connection outage probability (COP), the secrecy outage probability (SOP), and the secrecy throughput of the proposed system are obtained, based on which we optimize the time-switching ratio to maximize the secrecy throughput. We also degenerate the proposed SWIPT-FDSJ scheme to the reduced half-duplex with no self-jamming (HDNSJ) scheme. The finds suggest that in the HDNSJ scheme, adding the antenna number of the source only benefits the COP performance, but has no impact on the SOP performance. By contrast, it will promote the COP and SOP performance at the same time in the SWIPT-FDSJ scheme, which eventually results in the great improvement of secrecy throughput. In addition, we present the practical application condition of the SWIPT-FDSJ scheme. It is demonstrated that the secrecy throughput performance of the SWIPT-FDSJ scheme is much superior to the HDNSJ scheme on condition that the application condition is satisfied.
Security and energy are two critical Issues for emerging wireless networks and thus we study wireless energy harvesting and physical-layer security for a spectrum-sharing network with a multi-antenna full-duplex secondary receiver in the presence of an eavesdropper. We adopt a time-switching strategy where in the first phase, secondary users are powered through wireless energy transfer from the primary source. In the second phase, the secondary transmitter and receiver use the harvested energy to transmit the information and jamming signal, respectively. We propose a beamforming scheme at the secondary receiver with the main purpose of minimizing the outage probability of the secondary data transmission and maximizing the achievable secrecy rate of the primary system. We derive analytical expression for the outage probability at the secondary receiver and the achievable secrecy rate of the primary network. Moreover, asymptotic closed-form outage probability is presented. Numerical simulations verify the performance of the proposed scheme and analytical results and allow us to investigate the impact of the key system parameters on the network performance.