To guarantee secure information transmission within two sources, a full-duplex (FD) relay jamming scheme for two-way energy harvesting (EH) cooperative networks is proposed, in which the relay can achieve simultaneous information reception and jamming transmission. The EH relay node scavenges energy from two source signals, and then, uses the harvested energy for information relaying and jamming transmission by the power splitting (PS) protocol. Considering multiple eavesdroppers, the non-convex optimization for maximizing the smaller bidirectional secrecy rates is formulated by jointly optimizing the power allocation and PS factor. Furthermore, an iterative algorithm based on successive convex approximation and alternate search method is proposed to solve this non-convexity. Simulation results verify the proposed iterative algorithm and show that the proposed jamming scheme can achieve substantial performance gain than other conventional schemes.
To guarantee secure information transmission within two sources, a full-duplex (FD) relay jamming scheme for two-way energy harvesting (EH) cooperative networks is proposed, in which the relay can achieve simultaneous information reception and jamming transmission. The EH relay node scavenges energy from two source signals, and then, uses the harvested energy for information relaying and jamming transmission by the power splitting (PS) protocol. Considering multiple eavesdroppers, the non-convex optimization for maximizing the smaller bidirectional secrecy rates is formulated by jointly optimizing the power allocation and PS factor. Furthermore, an iterative algorithm based on successive convex approximation and alternate search method is proposed to solve this non-convexity. Simulation results verify the proposed iterative algorithm and show that the proposed jamming scheme can achieve substantial performance gain than other conventional schemes.
Abstract In this paper, for energy harvesting (EH) two‐way relay (TWR) networks with two‐sided eavesdroppers, the problem of secure information transmission is investigated. Based on this system model, a novel full‐duplex (FD) relaying jamming scheme is proposed to achieve simultaneously information reception, EH and jamming signal transmission at the cooperative relay. Particularly, the entire transmission phase and received signal at relay node are divided into two different time durations and three different parts by time allocation (TA) and power splitting (PS), respectively. For the aim of maximizing the sum secrecy rate, adaptive TA factor and PS factor are jointly optimized. We derive the non‐convex optimization function. To solve this highly non‐convex optimization problem, a heuristic approach based on particle swarm optimization (PSO) is proposed. Numerical results verify the superior sum secrecy rate of the proposed scheme. Besides, the impact of system parameters on the output performance is analyzed.
In this article, we investigated the secrecy performance of a three-hop relay network system with Power Splitting (PS) and Energy Harvesting (EH). In the presence of one eavesdropper, a signal is transferred from source to destination with the help of a relay. The source signal transmits in full-duplex (FD) mood, jamming the relay transfer signals to the destination. The relay and source employ Time Switching (TS) and Energy Harvesting (EH) techniques to obtain the power from the power beacon. In this study, we compared the Secrecy Rate of two Cooperative Schemes, Amplify and Forward (AF) and Decode and Forward (DF), for both designed systems with the established EH and PS system. The Secrecy Rate was improved by 50.5% in the AF scheme and by 44.2% in the DF scheme between the relay and eavesdropper at 40 m apart for the proposed system in EH and PS. This simulation was performed using the Monto Carlo method in MATLAB.
In this paper, the secure information transmission of an energy harvesting (EH) cooperative network is considered, in which multiple eavesdroppers can overhear the forwarded relay signal. To prevent multiple eavesdroppers from decoding confidential signals, the destination transmits the jamming signal while the source transmits the confidential signal to the relay. Simultaneously, the relay can harvest more energy from source signals and destination jamming by the power splitting (PS) protocol, which is depicted as a non-linear EH process. Considering the imperfect self-interference cancellation (SIC) at the destination, secrecy rate maximization optimization is formulated to optimize the transmission power of source and destination. However, the formulated optimization is non-convex. To solve this problem, an iterative algorithm is proposed based on the difference of convex functions (DC) programming, which can transform non-convex optimization problems into successive approximate convex problems. Simulation results show that the proposed algorithm has a quick convergence rate, and the proposed scheme leads to a higher achievable secrecy rate.
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.
This paper proposes a jointly cooperative relay and jamming protocol based on full-duplex (FD) capable relay to increase the source-destination secrecy rate in the presence of different types of eavesdroppers. In this so called FD-Relay with jamming (FDJ) protocol, the FD-Relay, first, simultaneously receives data and sends jamming to the eavesdropper, and, then, forwards the data, while the source jams the eavesdropper. Achievable secrecy rates of the proposed FDJ in the presence of different eavesdropper types and self-interference (SI) are derived and compared with those of the traditional half-duplex (HD) relay. The adaptive power allocation for secrecy rate maximization in a multi-carrier scenario for both proposed FDJ and HD-Relay is formulated as a non-convex optimization problem and corresponding iterative solution algorithm is developed using the difference-of-two-concave-functions (DC) programming technique. The simulation results confirm that FDJ offers significant improvements in the secrecy rate over the HD-Relay.
In this article, we raise the concern on secure energy efficiency (SEE) over the wireless-powered untrusted relay networks with nonlinear energy harvesting (EH). To achieve data confidentiality and secrecy performance enhancement concurrently, the untrusted relay can enable simultaneous energy signal reception and confidential information forwarding during the second phase, where no dedicated energy transmission phase or relaying signal splitting is needed for the energy supply. In particular, with the help of destination jamming, the relay can also harvest energy from source signal and jamming signal during the first phase, which is different from conventional relaying protocol that only harvests energy from source and recycled energy. Considering the nonlinear EH efficiency, our objective is to maximize the SEE through piecewise region selection and power allocation. To address this intractable nonconvex problem, a two-layer algorithm based on optimization decoupling, fractional programming, Lagrange dual decomposition and difference of convex functions (DC) programming is proposed. The core idea of the proposed algorithm is to convert the primary problem into simple subproblems by sequentially exploiting the above-mentioned optimization methods. Simulation results reveal the superior secrecy performance of the proposed scheme. The proposed algorithm achieves near-optimal solutions with faster convergence rate.