Summary This paper considers a full‐duplex (FD) secure transmission scheme with aid of the artificial noise deployed at both transmitter and receiver under imperfect self‐interference cancellation. The expressions of secrecy and connection outage probabilities are derived, and hence, the secrecy throughput of the proposed scheme is evaluated. The results show that the performance of the proposed FD scheme outperforms that of conventional half‐duplex and FD receiver schemes in terms of the secrecy outage probability. In addition, the proposed FD scheme can achieve high secrecy throughput under various locations of the eavesdropper. Especially when the eavesdropper is located close to the transmitter, the secrecy throughput of the proposed FD scheme is nearly double that of the half‐duplex scheme with artificial noise injection while that of the scheme with FD jamming receiver goes to zero.
Summary This paper considers a full‐duplex (FD) secure transmission scheme with aid of the artificial noise deployed at both transmitter and receiver under imperfect self‐interference cancellation. The expressions of secrecy and connection outage probabilities are derived, and hence, the secrecy throughput of the proposed scheme is evaluated. The results show that the performance of the proposed FD scheme outperforms that of conventional half‐duplex and FD receiver schemes in terms of the secrecy outage probability. In addition, the proposed FD scheme can achieve high secrecy throughput under various locations of the eavesdropper. Especially when the eavesdropper is located close to the transmitter, the secrecy throughput of the proposed FD scheme is nearly double that of the half‐duplex scheme with artificial noise injection while that of the scheme with FD jamming receiver goes to zero.
This letter considers a new secure communication scenario where a full-duplex transmitter (Alan) needs to transmit confidential information to a half-duplex receiver (Bob), with an eavesdropper (Eve) that tries to overhear the confidential information. For realizing the secure communication, we design an effective artificial-noise-aided secure scheme (ANAS) which is composed of two phases' transmissions: in Phase 1, Alan and Bob transmit two independent artificial noises (ANs) simultaneously, while in Phase 2, Alan superimposes the AN received in Phase 1 with its confidential signal and sends out the mixed signal. Since the superimposed AN by Alan in Phase 2 can be effectively cancelled by Bob while remains an interference to Eve, a secrecy rate could then be achieved. Importantly, we derive the approximate closed-form solutions of the average secrecy rate and secrecy outage probability of ANAS under a Rayleigh block-fading channel. Numerical results show that the secrecy rate of ANAS is about twice higher than the benchmark scheme, even though in ANAS half of the time is used to transmit ANs.
The issues of the physical layer security are studied, where one transmitter (Alice), one full‐duplex (FD) legitimate receiver (Bob) and one multi‐antenna jammer (Charlie) are considered to defend against multiple passive and non‐colluding eavesdroppers (Eves), for multiple‐input multiple‐output wiretap channels. With the assumption that the complete channel state information (CSI) for main channels and the statistical CSI for Eves' channels are available, an improved secrecy transmission design is proposed to minimise the secrecy outage probability (SOP), under the minimum secrecy rate requirement. In addition to integrating artificial noise aided transmit beamforming and multi‐antenna cooperative jammer to impair Eves' channels, which is widely used in many existing works, a FD legitimate receiver is applied together to further enhance physical layer security. Based on the basic probability theory and convex optimisation, the accurate closed‐form expression of the SOP is derived, and the impacts on secrecy performance are described, including the qualities of main channels, the Alice's transmit power and the number of Eves. Numerical results show that the proposed scheme using the FD Bob can significantly enhance the system security, as compared with that employing the half‐duplex Bob.
Abstract The satellite‐terrestrial downlink transmissions with larger coverage areas face more severe security challenges than terrestrial cellular communications due to the limitation of the satellite's power and the complexity of the channel. In this paper, the system model consists of one satellite, one legitimate user and multiple randomly distributed eavesdroppers while taking into account practical hardware impairments (HIs) at all transceivers involved. The Shadowed‐Rician fading model is adopted since it is a perfect fit for the satellite‐terrestrial channel. Besides, the full‐duplex (FD) operation is introduced in the destination where the receiver acquires the information signal and simultaneously emits the artificial noise (AN) to interfere with the nearby eavesdroppers. The maximal ratio combination scheme is applied to the destination to improve security. To facilitate evaluation of the effect of various parameters on the security performance, the closed‐form expressions of secrecy outage probability and ergodic secrecy capacity for the system are derived under the stochastic geometry framework. Finally, the simulation results show that the AN plays a pivotal role in improving the security performance, while the HIs can greatly deteriorate the performance, especially in the high transmit power regime. In addition, compared with the traditional half‐duplex receiver, the FD receiver have better security performance and can significantly alleviate the performance deterioration caused by HIs.
In this study, the authors consider secure communications in multiuser wireless networks where full‐duplex (FD) jamming operates to enhance physical layer security. The considered multiuser system is equipped with FD legitimate receivers in contrast to conventional frameworks where a half‐duplex (HD) receiver is at hand. This study investigates an alternative solution in which the authors take advantage of FD capability of the receivers to send jamming signals against the eavesdropper. Under these assumptions, the impact of self‐interference and channel interference on physical layer security is investigated. They derive the expressions of secrecy outage probability and ergodic secrecy rate in the proposed system. Two FD jammer selection schemes are proposed to further improve the security. In addition, they apply a reinforcement learning technology, called Q‐learning, to model the interaction between the source and multiple jamming users. The preliminary results show that the application of FD jamming and user selection scheme leads to a significant improvement in the wireless network security.
This paper investigates the secrecy performance of a full-duplex relaying (FDR) system with a full-duplex (FD) receiver. A novel cooperative jamming protocol is proposed to improve physical layer security, where the FD receiver sends interference to the eavesdropper to degrade its received signal-to-noise ratio when receiving signals from the relay and the source. Taking the residual self-interference (RSI) at both the relay and the FD receiver into consideration, the expressions of secrecy outage probability of the system are derived, where two independent behaviors of the relay toward the jamming signal are considered, 1) the jamming signal from the FD receiver is recognized as an interference at the relay; and 2) the jamming signal is priori known at the relay. Simulation results verified the correctness of the derived expressions and the effectiveness of the proposed protocol. It is demonstrated that the secrecy performance of the system can be significantly enhanced and the gain in terms of the decreased secrecy outage probability becomes more evident in case that the RSI is somewhat low when the proposed protocol is used.
This paper studies physical layer security in a wireless ad hoc network with numerous legitimate transmitter-receiver pairs and eavesdroppers. A hybrid full-duplex (FD)/half-duplex receiver deployment strategy is proposed to secure legitimate transmissions, by letting a fraction of legitimate receivers work in the FD mode sending jamming signals to confuse eavesdroppers upon their information receptions, and letting the other receivers work in the half-duplex mode just receiving their desired signals. The objective of this paper is to choose properly the fraction of FD receivers for achieving the optimal network security performance. Both accurate expressions and tractable approximations for the connection outage probability and the secrecy outage probability of an arbitrary legitimate link are derived, based on which the area secure link number, network-wide secrecy throughput, and network-wide secrecy energy efficiency are optimized, respectively. Various insights into the optimal fraction are further developed, and its closed-form expressions are also derived under perfect self-interference cancellation or in a dense network. It is concluded that the fraction of FD receivers triggers a non-trivial tradeoff between reliability and secrecy, and the proposed strategy can significantly enhance the network security performance.