Intelligent reflecting surface (IRS) has recently emerged as a new solution to enhance wireless communication performance via passive signal reflection. In this letter, we unlock the potential of IRS controller in relaying information and propose a novel IRS-assisted communication system with both IRS passive reflection and active relaying. Specifically, we jointly optimize the time allocations for decode-and-forward (DF) relaying by the IRS controller and the IRS passive beamforming to maximize the achievable rate of the proposed system. We also compare the rate performance of the proposed system with the conventional IRS without relaying, and reveal the conditions for one to outperform the other. Simulation results demonstrate that the proposed new design can significantly improve the coverage/rate performance of IRS-assisted systems.

中文翻译：

---

IRS 遇见中继：联合资源分配和无源波束成形优化


智能反射表面（IRS）最近成为一种通过无源信号反射增强无线通信性能的新解决方案。在这封信中，我们释放了 IRS 控制器在中继信息方面的潜力，并提出了一种具有 IRS 被动反射和主动中继功能的新型 IRS 辅助通信系统。具体来说，我们联合优化 IRS 控制器和 IRS 无源波束成形的解码转发 (DF) 中继的时间分配，以最大限度地提高所提出系统的可实现速率。我们还将所提出的系统与没有中继的传统 IRS 的速率性能进行了比较，并揭示了一个系统优于另一个系统的条件。仿真结果表明，所提出的新设计可以显着提高 IRS 辅助系统的覆盖/速率性能。