Enabling Wireless Communications in the Terahertz Band

近年来，由于当今社会创建、共享和消费信息的方式发生了变化，无线数据流量呈指数级增长。这种变化伴随着对更高速无线通信的日益增长的需求。每秒太比特的无线链路预计将在未来十年内成为现实。为了实现这一目标，太赫兹波段（0.1-10 THz）通信被设想为下一个十年的关键无线技术之一。THz频段将通过提供前所未有的大带宽，帮助克服当前无线网络的频谱稀缺问题和容量限制。此外，太赫兹波段通信将实现大量期待已久的应用，从太比特无线个人和局域网中附近设备之间的瞬时大规模数据传输，到5G和小型蜂窝以外的移动的设备上的超高清内容流。然而，由于太赫兹波段的信道具有很高的频率选择性路径损耗，而且距离非常有限，因此在研究方面存在一些挑战，这需要创新的解决方案，并对无线通信中的既定概念进行修改。本项目将为太赫兹波段的超宽带通信的发展铺平道路。太赫兹技术及其应用最近被DARPA确定为四个潜在影响比互联网本身更广泛的技术之一。超宽带通信将通过大幅增加无线网络的容量并实现当前无线技术无法实现的期待已久的应用，在社会中发挥重要作用。此外，THz频段尚未受到监管。该项目团队积极参与IEEE 802.15无线个域网太赫兹任务组，其目标是创建该范例的第一个标准。在这个项目中，一个研究生将被支持，硕士生（作为专题学生）将参与，成为这个快速发展的领域的专家。研究成果将在该领域的重要、一流的科学会议、期刊和主要杂志上传播。本项目的研究目标是加强太赫兹频段超宽带通信的理论基础，使太赫兹频段每秒太比特的链路更接近现实。我们的目标突破是将无线系统的容量提高到每秒太比特，并克服当前无线网络的频谱稀缺和容量限制。该项目将沿着沿着三大重点做出贡献。首先，超大规模的多输入多输出的概念被引入到克服距离的限制，基于使用非常大的天线阵列与数千个天线元件。分析了动态工作模式，包括波束形成、空间复用和两者的结合，以及多频带超大规模多输入多输出。其次，将建立三维端到端信道和三维超大质量多输入多输出信道的精确模型，这将为THz波段通信设计提供物理见解和指导。第三，通过捕捉独特的信道特性，距离自适应资源分配，低采样率和多载波同步方案将被调查的太赫兹波段通信。

In recent years, wireless data traffic has grown exponentially due to a change in the way today's society creates, shares and consumes information. This change has been accompanied by an increasing demand for higher speed wireless communication. Wireless Terabit-per-second links are expected to become a reality within the next ten years. Towards this aim, the Terahertz Band (0.1-10 THz) communication is envisioned as one of the key wireless technologies of the next decade. The THz band will help to overcome the spectrum scarcity problems and capacity limitations of current wireless networks, by providing an unprecedentedly large bandwidth. In addition, THz-band communication will enable a plethora of long-awaited applications ranging from instantaneous massive data transfer among nearby devices in Terabit Wireless Personal and Local Area Networks, to ultra-high-definition content streaming over mobile devices in 5G and beyond small cells. Nevertheless, there are several research challenges from the very-high and frequency-selective path loss of the THz-band channel and the very limited distance, which require innovative solutions and the revision of well-established concepts in wireless communication.This project will contribute to pave the way for the development of ultra-broadband communication in the THz band. THz technology and its applications has been recently identified by DARPA as one of the four with a potential broader impact larger than the Internet itself. Ultra-broadband communication will play a major role in the society by drastically increasing the capacity of wireless networks and enabling long-awaited applications not possible with current wireless technologies. In addition, the THz band is not yet regulated. The project team is actively involved in IEEE 802.15 Wireless Personal Area Network Terahertz Task Group, whose objective is to create the first standard for this paradigm. In this project, one graduate student will be supported, and master students (as special topic students) will be involved, to become experts in this fast evolving field. The research results will be disseminated in important, first rate scientific conferences, journals and premier magazines in the field. Moreover, the proposed solutions in this project can be tailored and are useful for the lower frequencies such as the millimeter-wave systems, which can help the development progress of 5G cellular systems.The research objective of this project is to strengthen the theoretical foundations of ultra- broadband communications in the THz band and bring the Terabit-per-second links one-step closer to reality. Our targeted breakthrough is to increase the capacity of wireless systems to reach Terabit-per-second and overcome the spectrum scarcity and capacity limitations of current wireless networks. This project will make contributions along three major thrusts. First, the concept of ultra-massive multiple-input-multiple-output is introduced to overcome the distance limitation, based on the use of the very large antenna arrays with thousands of antenna elements. The dynamic operation modes that include beamforming, spatial multiplexing and a combination of both, as well as the multi-band ultra-massive multiple-input-multiple-output will be analyzed. Second, accurate models for the three-dimensional end-to-end channel, and the three-dimensional ultra-massive multiple-input-multiple-output channel will be developed, which will provide physical insights and the guidelines for the THz band communication design. Third, by capturing the unique channel peculiarities, distance-adaptive resource allocation, and low-sampling-rate and multi-carrier synchronization schemes will be investigated for THz band communications.