CAREER: Taming the Terahertz for 6G Wireless Backhaul

下一代6G无线通信的一个基本要素将是无线回程。回程是在两点之间高速移动大量数据流的网络链路，支持移动和固定位置用户的大型子网。通常情况下，光纤传输回程数据，但光纤部署并不总是可行的；无线回程提供了高速替代方案和解决方案。6G将是第一代广泛部署的无线通信，其数据速率可与光纤相媲美，预示着我们的国家和社会的重要利益。农村和偏远地区的人口可能特别受益于无线回程，因为它支持宽带连接（有助于缩小数字鸿沟），而光纤部署成本过高。无线回程还将实现临时高速网络，这对移动军事单位、自然灾害恢复或季节性努力（如智能和互联农业）的操作至关重要。即使是城市中心以光纤为主的网络，在经济上和物流上也可能受益于无线回程段的高灵活性和相对较低的安装成本。此外，6G无线回程将战略性地利用0.1-10太赫兹之间长期未被充分利用的太赫兹频谱。实现无处不在的6G网络将需要大量新的研究，但太赫兹回程是重要的第一步。提出的工作将利用独特的实验测量、理论模型和新设备设计的组合来填补对现实条件下太赫兹回程性能理解的知识空白。所获得的知识将为未来6G系统的智能设计和优化奠定关键基础。此外，这项工作将培养新一代的学生，从高中到研究生水平，激励他们从事电气工程工作，并有能力在未来推进高度复杂的无线通信和传感技术。迄今为止，太赫兹通信的实验演示仍然非常罕见，在全面理解大气、天线指向、天气和湍流的影响方面留下了许多科学空白，特别是在采用超宽带和长距离的回程要求时。这种测量的缺乏进一步导致无法正确验证系统工程中使用的综合理论模型。项目目标和范围包括三个重点：1。测量真正的太赫兹回程链路，使间隙问题得以研究和正确理解；2. 以实验测量为验证标准，对理论通道模型进行修正，使之更加全面；3. 开发多功能反射射线，这是一种能够主动纠正太赫兹通信问题的设备，如天线指向、湍流和波束畸变。测量方法将依赖于美国国家科学基金会资助的一套独特的太赫兹系统，该系统旨在实现室内和室外敏感、远距离、超宽带的操作。理论模型将被扩展，以解释回程的独特属性，如超宽带，并将各种物理机制统一为一个单一的综合工具，通过该工具可以在任何实际情况下预测回程系统的行为。反射射线将通过推进用于回程特定目的的人工电磁材料概念来设计。这些努力将增强太赫兹无线通信知识，改进理论模型，并发明多功能设备，以提高未来6G无线系统的功率效率、速度、多功能性和可靠性。该项目由通信、电路和传感系统（CCSS）计划和促进竞争研究的既定计划（EPSCoR）共同资助。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

An essential element of next-generation 6G wireless communications will be wireless backhaul. Backhaul is the network link that moves massive data streams at high speed between two points, supporting large subnetworks of mobile and fixed-location users. Normally optical fibers carry backhaul data, but fiber deployment is not always viable; wireless backhaul provides the high-speed alternative and solution. 6G will be the first generation of widely deployed wireless communication that has data rates comparable to fiber optics, heralding important benefits to our nation and society. Rural and remote populations may especially benefit from wireless backhaul, since it supports broadband connectivity (helping to close the digital divide) where fiber deployment is cost prohibitive. Wireless backhaul would also enable temporary high-speed networks critical to operations in mobile military units, natural disaster recoveries, or seasonal endeavors, such as smart and connected farming. Even the fiber-dominated networks in urban centers may economically and logistically benefit from the high flexibility and relatively low installation cost of wireless backhaul segments. Further, 6G wireless backhaul will strategically leverage the long-underutilized terahertz spectrum between 0.1-10 THz. Realizing ubiquitous 6G networks will require much new research, but terahertz backhaul is an important first step. The proposed work will utilize a combination of unique experimental measurements, theoretical models, and new device designs to fill knowledge gaps in the understanding of terahertz backhaul performance under real-world conditions. The knowledge gained will establish the critical foundations upon which future 6G systems can be intelligently engineered and optimized. Moreover, this work will train a new generation of students, from high school to graduate levels, inspired to work in electrical engineering and capable of advancing the highly complex wireless communications and sensing technologies in the future.To date, experimental demonstrations of terahertz communication are still very rare, leaving numerous scientific gaps in the holistic understanding of the impact of the atmosphere, antenna pointing, weather, and turbulence, especially when employing the backhaul requirements of ultrawide bandwidth and long distance. This dearth of measurements further leads to an inability to properly validate comprehensive theoretical models used in system engineering. The project goals and scope involve three thrusts: 1. to measure real terahertz backhaul links and enable gap issues to be studied and properly understood; 2. to use experimental measurements as the validation standard upon which theoretical channel models can be corrected and made more comprehensive; 3. to develop multi-functional reflectarrays, which are devices that can actively correct – in situ – terahertz communication problems such as antenna pointing, turbulence, and beam distortion. The measurement method will rely on a unique NSF-funded suite of terahertz systems that are purposely built to enable sensitive, long-distance, ultrawide bandwidth operations, both indoors and outdoors. The theoretical modeling will be extended to account for backhaul-unique properties, such as ultrawide bandwidth, and to unify the various physical mechanisms into a single comprehensive tool by which backhaul system behavior can be predicted in any practical circumstance. Reflectarrays will be designed by advancing artificial electromagnetic material concepts for backhaul specific purposes. These efforts will enhance terahertz wireless communication knowledge, improve theoretical models, and invent multi-functional devices that improve the power efficiency, speed, versatility, and reliability of future 6G wireless systems.This project is jointly funded by the Communications, Circuits and Sensing Systems (CCSS) Program and the Established Program to Stimulate Competitive Research (EPSCoR).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.