Enhancing Physical Layer Security in Large Intelligent Surface-aided Cooperative Networks

Intelligent surfaces have recently been presented as a revolutionary technique and recognized as one of the candidates for beyond fifth-generation wireless networks. This paper investigates the physical layer security of a large intelligent surface (LIS) aided wireless system over Nakagami-m channels. We propose a phase-based adaptive modulation scheme, where LIS’s phase-shift optimization process is effectively utilized to enhance the system’s security. Moreover, the effect of the Nakagami-m fading parameter (m), correlation parameter ($\rho$), and a number of passive LIS elements (M) on the system performance are examined. The significant improvement in confidentiality is shown while evaluating the bit error rate performance of the proposed scheme.