RIS-Assisted Physical Layer Security: Artificial Noise-Driven Optimization and Measurements

TL;DR

This paper explores RIS-assisted physical layer security by optimizing artificial noise and signal direction, demonstrating improved secrecy capacity through simulations and real-world experiments.

Contribution

It introduces a novel RIS partitioning and phase shift optimization method for enhancing physical layer security in wireless networks.

Findings

Significant increase in secrecy capacity with RIS and artificial noise.

Effective RIS phase shift algorithms for practical implementation.

Successful validation through both simulations and testbed experiments.

Abstract

Reconfigurable intelligent surface (RIS) has emerged as a key enabler for providing signal coverage, energy efficiency, reliable communication, and physical layer security (PLS) in next-generation wireless communication networks. This paper investigates an artificial noise (AN)-driven RIS-assisted secure communication system. The RIS is partitioned into two segments, where the first segment is configured to direct the communication signal (CS) toward the legitimate user (Bob), and the other one is configured to steer the AN toward the eavesdropper (Eve). To this end, iterative and discrete Fourier transform-based algorithms are developed for practical RIS phase shift optimization. The power allocation between the CS and the AN signals is optimized in such a way that the secrecy capacity (SC) is maximized while limiting Eve's channel capacity. The proposed PLS framework is evaluated through both simulations and software defined radio based testbed experiments. The results demonstrate promising improvements in the SC, highlighting the potential of AN-driven RIS-assisted PLS for practical deployments.