This paper studies the secrecy throughput performance of the three-node wireless-powered networks and proposes two secure transmission schemes, namely the half-duplex maximal ratio combining (HD&MRC) scheme and the full-duplex jamming scheme based on time switching simultaneous wireless information and power transfer (FDJ&TS-SWIPT). The closed-form expressions of the secrecy throughput are derived, and intuitive comparison of the two schemes is provided. It is illustrated that the HD&MRC scheme only applies to the low and medium signal-to-noise ratio (SNR) regime. On the contrary, the suitable SNR regime of the FDJ&TS-SWIPT is much wider. It is depicted that FDJ&TS-SWIPT combing with current passive self-interference cancellation (SIC) algorithm outperforms HD&MRC significantly, especially when a medium or high transmit SNR is provided. Numerical simulations are conducted for verifying the validity of the analysis.
This paper studies the secrecy throughput performance of the three-node wireless-powered networks and proposes two secure transmission schemes, namely the half-duplex maximal ratio combining (HD&MRC) scheme and the full-duplex jamming scheme based on time switching simultaneous wireless information and power transfer (FDJ&TS-SWIPT). The closed-form expressions of the secrecy throughput are derived, and intuitive comparison of the two schemes is provided. It is illustrated that the HD&MRC scheme only applies to the low and medium signal-to-noise ratio (SNR) regime. On the contrary, the suitable SNR regime of the FDJ&TS-SWIPT is much wider. It is depicted that FDJ&TS-SWIPT combing with current passive self-interference cancellation (SIC) algorithm outperforms HD&MRC significantly, especially when a medium or high transmit SNR is provided. Numerical simulations are conducted for verifying the validity of the analysis.
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.
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.
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 work conducts the secrecy analysis of full-duplex power-splitting simultaneous wireless information and power transfer networks with artificial noise. The exact closed-form expressions of the COP, SOP and RSP are derived, respectively, which are illustrated by numerical analysis. The results depict the significance of the power-splitting ratio and the transmit signal-to-noise ratio (SNR). To be specific, the secrecy performance is greatly improved with the increasing of the power-splitting ratio. In addition, it is observed that the security of the system will get enhanced with the increasing of the power-splitting ratio at first and then get reversed for a certain transmit SNR. Moreover, the value of the optimum transmit SNR changes with different transmit SNR.
In this paper, the secrecy performance of full-duplex jamming SWIPT system is conducted where multiple eavesdroppers intercept the confidential information individually. The closed-form expressions of the connection outage probability (COP), the secrecy outage probability (SOP), the reliable-secure probability (RSP) and the secrecy throughput are obtained, which depict the secrecy performance of the system intuitively. The results demonstrate the significance of the power-splitting ratio, the transmit signal-to-noise ratio (SNR) and the secrecy information rate on the system security. All the observations indicate the existence of a optimum pair of the secrecy information rate and the power splitting ratio which maximize the secrecy throughput. Numerical results are provided for the validation of the analysis.
Simultaneous wireless information and power transfer (SWIPT) is a promising technique for energy-constrained wireless networks. To improve the security of SWIPT-enabled relay networks, in this paper, a full-duplex (FD) destination-aided jamming strategy is proposed, where a power splitting (PS) scheme is considered and two transmission phases are designed. In the first phase, the energy-limited half-duplex relay receives the signal superposed by confidential information and artificial noise (AN) from the source and destination, respectively. And then the FD destination transmits AN to the passive eavesdropper and receives the signal from the relay concurrently in the second phase. To maximize the secrecy capacity (SC), the individual optimizations of the PS ratio and power allocation (PA) coefficient are investigated, and the approximate optimal closed-form solutions of PS and PA ratios are derived. Besides, an iterative algorithm is also proposed to obtain the global optimal SC by updating the PS and PA ratios alternately. Simulation results confirm that the theoretical PS and PA ratios coincide closely with the exact results, and demonstrate that the optimal SC obtained by the iterative algorithm matches well with that given by the exhaustive search.