Collaborative Research: SWIFT: SMALL: Enabling Seamless Coexistence between Passive and Active Networks using Reconfigurable Reflecting Surfaces

多种无线技术之间的和谐共存对于无线电频谱的有效利用是必要的。然而，由于无线信道的随机性和不可控性，这使得难以限制共存无线系统之间的干扰，因此已知在实践中实现这一点具有挑战性。这一挑战因许多无线技术（如射电天文学）依赖于无源接收器而加剧，这些无源接收器的性能可能会被最轻微的干扰所破坏。然而，超材料的最新进展使得有可能开发可重构反射表面（RRS），其是电磁活性表面（例如，具有无线能力的墙），其可用于控制无线传播环境。因此，RRS可以潜在地帮助减轻共存的无线技术之间的干扰的挑战。本研究的目标是，因此，开发一种新的框架，将使多个无源和有源无线系统之间的无缝共存，通过开发所需的基本科学和技术，实际利用RRS的概念，以抑制在无线接收器的干扰。通过实现这一目标，拟议的研究将为实现广泛的无线技术和应用之间的无缝共存铺平道路。改进这些关键技术将产生切实的社会和经济影响。这项研究得到了一个全面的教育计划的补充，该计划包括以频谱为中心的课程，以及研究生和本科生通过频谱共享的各种活动的参与。具体的扩大参与活动，包括研讨会和参加科学博览会和推广活动，计划让代表性不足的K-12学生参与频谱研究。这项研究将为RRS增强的频谱共存网络的整体和跨层设计，分析，部署和优化开发基础分析和实验方法。这包括几个新的贡献：1）整体统计模型，其捕获频谱共享场景中RRS部署对无线传播环境的影响，并创建针对频谱共存用例定制的RRS启发的性能度量，2）用于网络规划的系统方法，其可用于确定部署多少RRS，其中，以及利用什么表面和取向以便于无缝通信，3）用于执行分布式频谱共享同时动态地利用RRS可重新配置性的新颖的在线优化框架，以及4）提供近连续波束操纵能力的RRS的设计和制造，该奖项反映了NSF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。

Harmonious coexistence between multiple wireless technologies is necessary for efficient utilization of the radio spectrum. However, enabling this in practice is known to be challenging because of the random and uncontrollable nature of the wireless channels, which makes it difficult to limit interference among co-existing wireless systems. This challenge is exacerbated by the fact that many wireless technologies, such as radio astronomy, rely on passive receivers whose performance can be disrupted by the slightest levels of interference. However, recent advances in metamaterials have made it possible to develop reconfigurable reflective surfaces (RRSs), which are electromagnetically active surfaces (e.g., a wall with wireless capabilities) that can be used to control the wireless propagation environment. Thus, RRSs can potentially help mitigate the challenge of interference among co-existing wireless technologies. The goal of this research is, thus, to develop a novel framework that will enable seamless co-existence among multiple passive and active wireless systems, by developing the fundamental science and technology needed to practically exploit the RRS concept to suppress interference at the wireless receivers. By achieving this goal, the proposed research will pave the way towards a seamless co-existence among a broad range of wireless technologies and applications. Improving these critical technologies will have tangible societal and economic impacts. The research is complemented by a comprehensive educational plan that includes spectrum-centric courses as well as the involvement of graduate and undergraduate students through diverse activities on spectrum sharing. Concrete broadening participation events, including seminars and participation in science fairs and outreach activities, are planned to engage under-represented K-12 students in spectrum research.This research will develop foundational analytical and experimental approaches for holistic and cross-layer design, analysis, deployment, and optimization of RRS-enhanced spectrum co-existence networks. This includes several novel contributions: 1) A holistic statistical model that captures the effect of RRS deployment on the wireless propagation environment in spectrum sharing scenarios and creates RRS-inspired performance metrics tailored to spectrum co-existence use cases, 2) A systematic approach for network planning that can be used to determine how many RRSs to deploy, where, and with what surface and orientation so as to facilitate seamless communication, 3) A novel online optimization framework for performing distributed spectrum sharing while dynamically leveraging RRS reconfigurability, and 4) Design and fabrication of an RRS that offers near-continuous beam steering capability, as well as an experimental demonstration of RRS-enhanced spectrum co-existence in practical settings.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.