Intelligent reflecting surface (IRS) is an enabling technology to engineer the radio signal prorogation in wireless networks. By smartly tuning the signal reflection via a large number of low-cost passive reflecting elements, IRS is capable of dynamically altering wireless channels to enhance the communication performance. It is thus expected that the new IRS-aided hybrid wireless network comprising both active and passive components will be highly promising to achieve a sustainable capacity growth cost-effectively in the future. Despite its great potential, IRS faces new challenges to be efficiently integrated into wireless networks, such as reflection optimization, channel estimation, and deployment from communication design perspectives. In this paper, we provide a tutorial overview of IRS-aided wireless communication to address the above issues, and elaborate its reflection and channel models, hardware architecture and practical constraints, as well as various appealing applications in wireless networks. Moreover, we highlight important directions worthy of further investigation in future work.

中文翻译：

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智能反射表面辅助无线通信：教程

智能反射面 (IRS) 是一种在无线网络中设计无线电信号传播的使能技术。通过大量低成本的无源反射元件巧妙地调整信号反射，IRS 能够动态改变无线信道以提高通信性能。因此，预计包含有源和无源组件的新型 IRS 辅助混合无线网络将在未来经济高效地实现可持续的容量增长。尽管 IRS 潜力巨大，但要有效地集成到无线网络中仍面临着新的挑战，例如反射优化、信道估计和通信设计角度的部署。在本文中，我们提供了 IRS 辅助无线通信的教程概述以解决上述问题，并详细阐述其反射和信道模型、硬件架构和实际约束，以及无线网络中的各种吸引人的应用。此外，我们强调了值得在未来工作中进一步研究的重要方向。