Physical Layer Security Enhancement via Intelligent Omni-Surfaces and UAV-Friendly Jamming

Abstract

Intelligent reflecting surfaces (IRS) are considered one of the prominent technologies to be adopted in 6G and beyond networks. However, one of the main IRS limitations is restricting the communication to the reflective dimension, which means that users located behind the IRS surface cannot benefit from it. In this paper, we make use of intelligent omni-surfaces (IOS), as an alternative to IRS, in addition to unmanned aerial vehicles (UAV) to achieve secure communication in an Internet-of-Things (IoT) communication system. Specifically, we propose IOS-UAV assisted communication wherein an access point (AP) tries to send confidential information to a legitimate IoT device in presence of an eavesdropper. The UAV serves two fold; it acts as a friendly jammer that is trying to degrade the signal quality at the eavesdropper and as a source of energy to power up the IoT device via simultaneous wireless information and power transfer (SWIPT) to address the limited power available to it. We formulate an average secrecy rate maximization problem, which jointly optimizes the AP and UAV transmission powers, the UAV trajectory, IOS phase shifts and power splitting factor. The formulated problem is non-convex, therefore we exploit successive convex approximation (SCA) to tackle this issue. Simulation results show that the iterative SCA solution converges rapidly. Besides, the proposed scheme outperforms the traditional system without IOS by a gap of 140% in terms of the secrecy capacity.INDEX TERMS Intelligent omni-surface, unmanned aerial vehicle, simultaneous wireless information and power transfer, physical layer security, Internet of things, successive convex approximation.

Double-Faced Active Intelligent Reflecting Surfaces-Assisted Symbiotic Radio Communications

“…This requires a full-dimensional coverage that cannot be assured through the deployment of conventional passive/active IRS, which is the case in all the previously mentioned research studies. Simultaneously transmitting and reflecting IRS (STAR-IRS), which are also known as intelligent-omni-surfaces (IOS), have been proposed in the past few years to provide this full-dimensional coverage [31]- [33]. In STAR-IRS, the incident signal on the surface can be split into two parts; one reflected to the same half space as the incident signal while the other part is transmitted to the opposite half space of the incident signal.…”

Improving the Capacity of NOMA Network Using Multiple Aerial Intelligent Reflecting Surfaces

“…Then, the specific moments of A t can be clarified from (56), i.e., µ At (1) = µ Ht (1) + µ |nst| (1)…”

“…Recently, intelligent reflecting surface (IRS) has emerged as an effective solution to dramatically enhance the performance and coverage of future wireless networks [1], [2]. In particular, IRS can intelligently reflect the radio frequency (RF) signals without signal processing and power supply [3], [4].…”

“…• We obtain the exact expressions of ECs at users of the proposed NOMA-AIRS network over practical Nakagami-m environments recommended to utilize in 5G & B5G standards 1 . It is obvious that the obtained expressions are more complex than those of the previous works where only one AIRS and only one user were used [11], [12], [14], [25].…”

Relay Selection for Improving Physical Layer Security in D2D Underlay Communications

“…An SCA-based procedure to maximize secrecy rate by optimizing BS and UAV transmit powers, UAV trajectory, transmit and reflect phase shifts of RIS, and power splitting factor at the legitimate receiver under UAV trajectory constraints, power budgets, power splitting and energy harvesting constraints, and RIS phase constraints was examined in [263]. The study in [189] focused on maximizing the secrecy rate by optimizing BS beamforming vector and RIS phase shifts under transmit power budget and RIS phase shift constraint.…”