Physical Layer Service Integration in 5G: Potentials and Challenges

High transmission rate and secure communication have been identified as the key targets that need to be effectively addressed by fifth generation (5G) wireless systems. In this context, the concept of physical-layer security becomes attractive, as it can establish perfect security using only the characteristics of wireless medium. Nonetheless, to further increase the spectral efficiency, an emerging concept, termed physical-layer service integration (PHY-SI), has been recognized as an effective means. Its basic idea is to combine multiple coexisting services, i.e., multicast/broadcast service and confidential service, into one integral service for one-time transmission at the transmitter side. This article first provides a tutorial on typical PHY-SI models. Furthermore, we propose some state-of-the-art solutions to improve the overall performance of PHY-SI in certain important communication scenarios. In particular, we highlight the extension of several concepts borrowed from conventional single-service communications, such as artificial noise (AN), eigenmode transmission etc., to the scenario of PHY-SI. These techniques are shown to be effective in the design of reliable and robust PHY-SI schemes. Finally, several potential research directions are identified for future work.Comment: 12 pages, 7 figure

Game theory-based resource allocation for secure WPCN multiantenna multicasting systems

This paper investigates a secure wireless-powered multiantenna multicasting system, where multiple power beacons (PBs) supply power to a transmitter in order to establish a reliable communication link with multiple legitimate users in the presence of multiple eavesdroppers. The transmitter has to harvest radio frequency (RF) energy from multiple PBs due to the shortage of embedded power supply before establishing its secure com- munication. We exploit a novel and practical scenario that the PBs and the transmitter may belong to different operators and a hierarchical energy interaction between the PBs and the transmitter is considered. Specifically, the monetary incentives are required for the PBs to assist the transmitter for secure communications. This leads to the formulation of a Stackelberg game for the secure wireless-powered multiantenna multicasting system, where the transmitter and the PB are modelled as leader and follower, respectively, each maximizing their own utility function. The closed-form Stackelberg equilibrium of the formulated game is then derived where we study various scenarios of eavesdroppers and legitimate users that can have impact on the optimality of the derived solutions. Finally, numerical results are provided to validate our proposed schemes

Game theory-based resource allocation for secure WPCN multiantenna multicasting systems

This paper investigates a secure wireless-powered multiantenna multicasting system, where multiple power beacons (PBs) supply power to a transmitter in order to establish a reliable communication link with multiple legitimate users in the presence of multiple eavesdroppers. The transmitter has to harvest radio frequency (RF) energy from multiple PBs due to the shortage of embedded power supply before establishing its secure com- munication. We exploit a novel and practical scenario that the PBs and the transmitter may belong to different operators and a hierarchical energy interaction between the PBs and the transmitter is considered. Specifically, the monetary incentives are required for the PBs to assist the transmitter for secure communications. This leads to the formulation of a Stackelberg game for the secure wireless-powered multiantenna multicasting system, where the transmitter and the PB are modelled as leader and follower, respectively, each maximizing their own utility function. The closed-form Stackelberg equilibrium of the formulated game is then derived where we study various scenarios of eavesdroppers and legitimate users that can have impact on the optimality of the derived solutions. Finally, numerical results are provided to validate our proposed schemes

On Secrecy Performance for Energy-Harvesting Multi-Antenna Relaying Networks with a Dual-Use Source

This paper studies the secrecy performance of an energy-harvesting relaying system in the presence of a dual-use source node and an eavesdropper. Specifically, the source has dual roles in the dual-hop communication: 1) to transmit confidential information in the first hop; 2) to generate jamming signal to interfere the eavesdropper in the second hop. Moreover, the multi-antenna relay deploys a power-splitting harvesting scheme to coordinate the information receiving and energy harvesting, and adopts maximal ratio combining technique to process the multiple copies of signals. Considering decode-and-forward protocol and transmit antenna selection scheme, we derive an analytical expression for secrecy outage probability, and perform Monte Carlo simulation to validate the analysis. Analytical results show that the SOP performance with the dual-use source node can be effectively improved when the relay-destination channel does not have absolute advantage over the relay-eavesdropper channel

The Role of Physical Layer Security in Satellite-Based Networks

In the coming years, 6G will revolutionize the world with a large amount of bandwidth, high data rates, and extensive coverage in remote and rural areas. These goals can only be achieved by integrating terrestrial networks with non-terrestrial networks. On the other hand, these advancements are raising more concerns than other wireless links about malicious attacks on satellite-terrestrial links due to their openness. Over the years, physical layer security (PLS) has emerged as a good candidate to deal with security threats by exploring the randomness of wireless channels. In this direction, this paper reviews how PLS methods are implemented in satellite communications. Firstly, we discuss the ongoing research on satellite-based networks by highlighting the key points in the literature. Then, we revisit the research activities on PLS in satellite-based networks by categorizing the different system architectures. Finally, we highlight research directions and opportunities to leverage the PLS in future satellite-based networks

Wireless powered communication networks using peer harvesting

For an energy-constrained wireless network, energy harvesting (EH) is a promising technology to prolong the network life. Whether traditional near-field wireless power transfer (WPT) using inductive and resonant coupling or far-field WPT via radiated electromagnetic waves, both of them draw considerable research interests these years [1], [2]. In particular, the far-field WPT is meaningful for wireless powered communication (WPC) networks. A fundamental tradeoff was first studied for simultaneous wireless information and power transfer (SWIPT) in [3], [4]. These results aroused the interest of researchers. Subsequently, wireless communication with EH technology was presented in [5], [6]

Robust AN-Aided Secure Beamforming and Power Splitting in Wireless-Powered AF Relay Networks

In this letter, we investigate the secrecy design in a wireless-powered amplify-and-forward relay network, where the relay is energy constrained and powered by the signal from the transmitter. Specifically, by adopting the power splitting (PS) scheme at the relay, we investigate the worst-case secrecy rate maximization by jointly designing the relay beamforming matrix, artificial noise covariance, and the PS ratio. However, the formulated problem is highly nonconvex due to the secrecy rate function and the dynamic relay power constraint. By exploiting the hidden convexity, we transform the original problem to a solvable reformulation via the successive convex approximation and constrained concave–convex procedure, which can provide a high-level approximated beamforming solution. Then, an iterative algorithm is proposed to obtain the solution. Numerical results showed the effectiveness of the proposed robust scheme