In this paper, the joint receiving antenna selection and full-duplex zero-forcing jamming scheme is presented to safeguard the information transmission of the multi-antenna wireless-powered networks. The performance of the connection outage probability, the secrecy outage probability, and the secrecy throughput are investigated whose closed-form expressions are derived. It is shown that the COP and the SOP are decreasing and increasing functions of the transmit power of jamming node and its antennae number, and , respectively. Moreover, the findings indicate the existence of an optimum secrecy rate per channel use for maximizing the ST. Besides, we also find that at the low regime of , the decline of COP with the increasing of is dominant to ST and the increment of SOP can be ignored, which turns to the opposite at the high regime. This result implies that a smaller is suggested at the low regime of while a larger one is preferred at the high regime for pursuing a better ST performance. Numerical simulations are carried out to validate the preciseness of the theoretical analysis.
In this paper, the joint receiving antenna selection and full-duplex zero-forcing jamming scheme is presented to safeguard the information transmission of the multi-antenna wireless-powered networks. The performance of the connection outage probability, the secrecy outage probability, and the secrecy throughput are investigated whose closed-form expressions are derived. It is shown that the COP and the SOP are decreasing and increasing functions of the transmit power of jamming node and its antennae number, and , respectively. Moreover, the findings indicate the existence of an optimum secrecy rate per channel use for maximizing the ST. Besides, we also find that at the low regime of , the decline of COP with the increasing of is dominant to ST and the increment of SOP can be ignored, which turns to the opposite at the high regime. This result implies that a smaller is suggested at the low regime of while a larger one is preferred at the high regime for pursuing a better ST performance. Numerical simulations are carried out to validate the preciseness of the theoretical 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.
In this paper, we investigate the secrecy performance of wireless powered communication networks (WPCNs) faced by multiple passive eavesdroppers, where the full-duplex (FD) receiver utilizes the harvested energy to send the artificial jamming for enhancing the secrecy performance. Moreover, we adopt a practical maximal ratio transmission (MRT) scheme at the transmitter taking into account the impact of imperfect CSI to try to improve the transmission efficiency of the considered system. Specifically, in order to evaluate the proposed scheme, three important performance metrics, namely, connect outage probability (COP), secrecy outage probability (SOP), and secrecy throughput are adopted in this paper. Concretely, the exact and asymptotic expressions for COP, SOP, and secrecy throughput were derived to effectively analyze the impact of key parameters on the system performance more comprehensively. Through the simulation analysis, we can find that the proposed energy harvesting-based FD-aid jamming (EHFDJ) scheme can achieve better secrecy performance than the reduced half-duplex non-jamming (HDNJ) scheme under a relatively small self-interference.
In this paper, the physical-layer security of a cooperative wireless system with multi-antenna full-duplex (FD) destination is examined. More specifically, we consider a cooperative transmission scenario in which a source communicates with a destination through a relay in the presence of an eavesdropper. In order to degrade the wiretap channel, the FD destination simultaneously transmits an interference signal towards the eavesdropper, while receiving information from the relay. A joint transmit and receive beamformer design is proposed to maximize the signal-to-interference-plus-noise ratio (SINR) at the destination, while guaranteeing that the SINR at the eavesdropper is below a certain threshold. We reformulate the optimization problem as a semidefinite relaxation problem in terms of a transmit beamforming matrix. To balance the performance and system complexity, we investigate suboptimum beamforming designs based on zero-forcing criterion. We derive exact closed-form expressions for the average secrecy rates of the proposed suboptimum designs. Our results reveal that optimum and suboptimum beamforming schemes along with friendly jamming significantly improve the secrecy performance. Moreover, simulation results demonstrate that the optimum scheme outperforms suboptimum schemes, especially in high transmit power regimes.
In this paper, we investigate the secrecy performance of full-duplex multi-antenna spectrum-sharing wiretap networks in which a jamming signal is simultaneously transmitted by the full-duplex secondary receiver (Bob) based on the zero forcing beamforming (ZFB) algorithm. For the security enhancement, we propose the two antenna reception schemes: 1) random selection combining (RSC) where Bob selects LB antennas at random to combine the received signals and 2) generalized selection combining (GSC) where Bob selects LB strongest antennas to combine the received signals. We derive the exact closed-form expressions for the secrecy outage probability of full-duplex multi-antenna spectrum-sharing wiretap networks with ZFB algorithm. In order to explore a new design of the proposed schemes, we provide tractable asymptotic approximations for the secrecy outage probability in high signal-to-noise ratio regime under two distinct scenarios. From the analysis, we demonstrate that: 1) when the main channel is much better than the eavesdropper's channel, GSC/ZFB scheme achieves full diversity NB, while RSC/ZFB scheme only achieves partial diversity LB and 2) GSC/ZFB scheme achieves better secrecy performance than RSC/ZFB with different antenna numbers at Bob.
This paper investigates secure communications of energy harvesting untrusted relay networks, where the destination assists jamming signal to prevent the untrusted relay from eavesdropping and to improve the forwarding ability of the energy constrained relay. Firstly, the source and the destination transmit the signals to the relay with maximal ratio transmission (MRT) technique or transmit antenna selection (TAS) technique. Then, the destination utilizes maximal ratio combining (MRC) technique or receive antenna selection (RAS) technique to receive the forwarded information. Therefore, four transmission and reception schemes are considered. For each scheme, the closed-form expressions of the secrecy outage probability (SOP) and the connection outage probability (COP) are derived. Besides, the effective secrecy throughput (EST) metric is analyzed to achieve a good tradeoff between security and reliability. In addition, the asymptotic performance of EST is also considered at the high signal-to-noise ratio (SNR). Finally, simulation results illustrate that: (1) the EST of the system with MRT and MRC scheme are superior to other schemes, however, in the high SNR regime, the EST of the system with MRT scheme is inferior to TAS; and (2) for the source node, there exists an optimal number of antennas to maximize the EST of the proposed schemes.
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.