Secure Communication in Dynamic RDARS-Driven Systems

TL;DR

This paper proposes a novel dynamic RDARS-driven secure communication system that maximizes secrecy rate through joint design of beamforming, reflection, and mode selection, using an efficient optimization framework.

Contribution

It introduces a new optimization framework for dynamic RDARS systems, enabling flexible mode configuration and improved secrecy performance over existing schemes.

Findings

RDARS significantly enhances secrecy rate.

The proposed optimization outperforms existing reflection surface schemes.

Simulation confirms the effectiveness of dynamic mode selection.

Abstract

In this letter, we investigate a dynamic reconfigurable distributed antenna and reflection surface (RDARS)-driven secure communication system, where the working mode of the RDARS can be flexibly configured. We aim to maximize the secrecy rate by jointly designing the active beamforming vectors, reflection coefficients, and the channel-aware mode selection matrix. To address the non-convex binary and cardinality constraints introduced by dynamic mode selection, we propose an efficient alternating optimization (AO) framework that employs penalty-based fractional programming (FP) and successive convex approximation (SCA) transformations. Simulation results demonstrate the potential of RDARS in enhancing the secrecy rate and show its superiority compared to existing reflection surface-based schemes.