Towards Intelligent Reflecting Surface Empowered 6G Terahertz Communications: A Survey
Towards Intelligent Reflecting Surface Empowered 6G Terahertz Communications: A Survey
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DOI：
10.23919/jcc.2021.05.007
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发表时间：
2021-05-01
影响因子：
4.1
通讯作者：
Wen, Qiye
中科院分区：
文献类型：
--
作者：
Chen, Zhi;Ma, Xinying;Wen, Qiye
太赫兹（THz）通信已被广泛设想为提供足够带宽并实现第六代（6G）无线网络的超高数据速率的有前景的使能器。为解决太赫兹波传播衰减严重、衍射不良等问题，提出了一种智能反射面（IRS），通过调节无源反射元件的相移，以可编程方式控制入射电磁波的传播，以创建智能无线电环境，提高频谱利用率，增强覆盖能力。首先，介绍了IRS支持的THz通信应用场景，包括无线移动的通信、保密通信、无人机（UAV）应用场景、移动的边缘计算（MEC）应用场景和THz定位应用场景。然后，我们讨论了IRS授权的THz系统所采用的使能技术，包括硬件设计、信道估计、容量优化、波束控制、资源分配和鲁棒性设计。此外，所出现的挑战和开放的问题，在未来的IRS授权的太赫兹通信也被强调。具体而言，这些新出现的问题可能源于信道建模、新材料探索、实验IRS测试床和密集部署。最终，太赫兹通信和IRS的结合能够加速6G无线网络的发展。
Terahertz (THz) communications have been widely envisioned as a promising enabler to provide adequate bandwidth and achieve ultra-high data rates for sixth generation (6G) wireless networks. In order to mitigate blockage vulnerability caused by serious propagation attenuation and poor diffraction of THz waves, an intelligent reflecting surface (IRS), which manipulates the propagation of incident electromagnetic waves in a programmable manner by adjusting the phase shifts of passive reflecting elements, is proposed to create smart radio environments, improve spectrum efficiency and enhance coverage capability. Firstly, some prospective application scenarios driven by the IRS empowered THz communications are introduced, including wireless mobile communications, secure communications, unmanned aerial vehicle (UAV) scenario, mobile edge computing (MEC) scenario and THz localization scenario. Then, we discuss the enabling technologies employed by the IRS empowered THz system, involving hardware design, channel estimation, capacity optimization, beam control, resource allocation and robustness design. Moreover, the arising challenges and open problems encountered in the future IRS empowered THz communications are also highlighted. Concretely, these emerging problems possibly originate from channel modeling, new material exploration, experimental IRS testbeds and intensive deployment. Ultimately, the combination of THz communications and IRS is capable of accelerating the development of 6G wireless networks.