NeTS: Small: Small Terahertz Cells

在无线技术无处不在的今天，我们面临着严重的频谱短缺。太赫兹频段(100 GHz到10 THz)是频谱中很大程度上未被使用的部分，可以潜在地用于高速率短距离无线链路，从而在一定程度上缓解频谱压力。然而，该频段会受到随距离变化的大信号衰减的影响，因此需要高度定向的传输(或铅笔形波束)。这项研究确定了在房间和其他短距离应用领域实现这种定向传输以提供覆盖的基本挑战。此外，鉴于覆盖的高度方向性，该项目研究了向移动用户分配频谱资源的问题，这导致了对频率可用性的空间依赖。这项工作的影响是广泛的：它通过研究迄今未被探索的频谱部分来解决频谱稀缺的根本问题，并将影响新兴的5G无线标准。PI还将教授一个关于太赫兹通信的研究生研讨会课程，从而影响教育。该项目描述了使用密集天线阵列在太赫兹频谱上提供高度定向覆盖的频率和角度相关性。这种行为的一个后果是，除非仔细规划覆盖范围，否则即使用户移动几英尺，数据速率也可能下降数量级。本项目提出了一种系统的方法来研究使用密集天线阵列集群的太赫兹网络的覆盖问题。该项目还研究了一种使用镜片提供覆盖范围的新方法。第一个问题将通过建立一个详细的太赫兹传播模拟器来研究，其中包括密集天线阵列的模型和互耦合效应的模型(这两个模型在这个频段很重要)。后一种方法将使用大量测量数据进行研究。鉴于这些研究，该项目将审查为房间内的移动用户提供覆盖的问题。由于频谱资源表现出空间相关性，确保用户继续获得所需的服务质量的问题将结合资源分配方法和几何约束。这项研究的结果将是对太赫兹通信信道的详细了解，以及一套可供该领域其他研究人员使用的工具和测量方法。

With the ubiquitous use of wireless technology today, we are experiencing a severe shortage of spectrum. The terahertz frequency band (100 GHz to 10 THz) is a largely unused part of the spectrum that can potentially be used for high rate short-range wireless links thus easing the spectrum pressure to some degree. However, this frequency band suffers from large signal attenuation with distance, resulting in a need for highly directional transmissions (or pencil beams). This research identifies fundamental challenges in implementing such directional transmissions for providing coverage in rooms and other short-range application domains. Additionally, the project examines the problem of allocating spectrum resources to mobile users given the highly directional nature of coverage, which causes a spatial dependence on frequency availability. The impact of this work is broad: it addresses the fundamental problem of spectrum scarcity by examining a hitherto unexplored part of the spectrum and it will impact the emerging 5G wireless standard. The PI will also teach a graduate seminar class on terahertz communications, thus impacting education.The project describes the frequency and angular dependence of using dense antenna arrays to provide highly directional coverage across the terahertz spectrum. A consequence of this behavior is that as a user moves even a few feet, the data rate can drop by orders of magnitude, unless coverage is planned carefully. This project presents a systematic approach to studying the coverage problem for terahertz networks using clusters of dense antenna arrays. The project also examines a novel approach of using lenses to provide coverage. The first problem will be studied by building a detailed terahertz propagation simulator, which includes models for dense antenna arrays and models for mutual coupling effects (which are significant at this frequency band). The latter approach will be studied using a large set of measurements. Given these studies, the project will then examine the problem of providing coverage to mobile users in rooms. Since spectrum resources show a spatial dependence, the problem of ensuring users continue to receive their required quality of service will combine resource allocation approaches with geometric constraints. The outcome of this research will be a detailed understanding of the terahertz communication channel as well as a set of tools and measurements that can be employed by other researchers in the field.