Phase Shift Information Compression in IRS-Aided Wireless Systems: Challenges and Opportunities

Intelligent reflecting surfaces (IRS) have emerged as a promising technology for future 6G wireless networks, offering programmable control of the wireless environment by adjusting the phase shifts of reflecting elements. However, IRS performance depends on accurately configuring the phase shifts of reflecting elements, which introduces substantial phase shift information (PSI) delivery overhead, especially in large-scale or rapidly changing environments. This article first introduces the architecture of IRS-aided systems and highlights real-world use cases where PSI delivery becomes a critical bottleneck. It then reviews current PSI compression approaches, outlining their limitations in terms of adaptability and scalability. To address these gaps, we propose a prompt-driven plug-in module that leverages task-aware prompts to achieve efficient, real-time PSI delivery under diverse conditions. Simulation results demonstrate improved reconstruction accuracy and robustness compared with the baseline method. Finally, we discuss open challenges and outline promising directions for future research.