Intelligent Dynamic Switching Between IRS and Decode-and-Forward Relay: A Channel-Aware Optimization Approach for 6G Networks

Abstract

This paper proposes a dynamic switching framework between Intelligent Reflecting Surface (IRS) and Decode-and-Forward (DF) relay transmission modes for next-generation wireless communication systems. Unlike existing studies that rely on static technology selection, the proposed approach enables channel-aware mode adaptation based on instantaneous channel conditions and energy efficiency considerations. The framework supports four operational modes: IRS-only, DF-only, hybrid IRS–DF, and direct SISO transmission. An efficient mode selection algorithm is developed to maximize achievable rate while accounting for power consumption and switching overhead. Simulation results demonstrate up to 20.2% improvement in spectral efficiency and 10.1% enhancement in energy efficiency compared to conventional static schemes, under realistic channel conditions. The proposed framework exhibits low computational complexity, making it suitable for practical 6G network deployment.