SpecEES: Spectrally-Efficient Near-Zero-Power IoT Connectivity with Existing Wi-Fi Infrastructure

为了真正实现无处不在的设备连接到互联网（物联网或物联网）的愿景，连接应该是可能的，部署，设备和运营成本的开销最小。为了限制部署开销，应通过现有基础设施进行无线连接。不幸的是，企业和医疗机构中最流行的无线网络是Wi-Fi，并且Wi-Fi芯片组的功耗太大（数百毫瓦），无法轻松地由小型纽扣电池供电，而无需频繁更换或重新充电电池的大量运营成本。因此，目前物联网设备（如谷歌的Nest系统）的部署仅限于可以插入电源的位置。这个问题目前阻碍了新物联网设备概念的创新。由于使用传统技术降低Wi-Fi收发器的功耗是不可能的，因此需要新的通信方法。该提案的主要目标是实现新类型的电池供电物联网设备，这些设备可以通过反射或反向散射现有的Wi-Fi信号直接与Wi-Fi接入点进行通信。由于后向散射仅需要具有计算上宽松的基带规格的反射电路的无源天线，因此可以实现物联网设备级的低功耗操作。成功的研究将使物联网设备更快地应用于现有基础设施，并将实现新的低功耗环境、工业、智能家居和健康监测应用。除了启用令人兴奋的新应用程序，该项目还提出了一个协同教育和推广计划，利用赠款中执行的技术工作，以建立令人兴奋的新演示，用于本科和K-12课堂设置。例如，一种基于水果的能量采集系统为开发的低功耗标签供电，该标签直接与Wi-Fi设备通信，将以务实而引人注目的方式向学生介绍工程学的奇迹，希望增加科学，技术，工程和数学（STEM）相关教育环境的多样性。这项工作旨在实现第一个实用的低功耗、低成本集成电路解决方案，该解决方案可以使反向散射标签网络与现有的Wi-Fi协议连接。这将是第一个包括低功耗通用WiFi唤醒接收器的设备，用于反向散射标签的有效同步和介质访问控制，然后反向散射Wi-Fi兼容信号与物联网数据一起携带。重要的是，拟议的后向散射平台将与所有现有的Wi-Fi基础设施无缝运行，从而不会干扰现有的频谱效率高的生产通信。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

In order to truly enable the vision of ubiquitous devices connected to the Internet (Internet-of Things or IoT), connections should be possible with a minimal overhead for deployment, device and operational costs. To limit the deployment overhead, wireless connectivity should occur via existing infrastructure. Unfortunately, the most popular wireless network in enterprises and healthcare facilities is Wi-Fi, and the power consumption of Wi-Fi chipsets is too large (100s of milliwatts) to be easily powered by small coin cell batteries without large operational costs to frequently replace or re-charge batteries. As a result, current deployments of IoT devices (like Google's Nest systems) are limited to locations where they can be plugged into a power source. This issue is currently holding back innovation in new IoT device concepts. Since reducing the power consumption of Wi-Fi transceivers using conventional techniques is not possible, a new communication approach is needed. The primary objective of this proposal is to enable new classes of battery-powered IoT devices that can directly communicate with Wi-Fi access points by just reflecting or backscattering existing Wi-Fi signals. Since backscattering requires only a passive antenna with a reflection circuit with computationally relaxed baseband specifications, low-power operation at the IoT device-level can be achieved. Successful research will enable more rapid adoption of IoT devices into existing infrastructure and will enable new classes of low-power environmental, industrial, smart home, and health monitoring applications. Beyond enabling exciting new applications, the project also proposes a synergistic educational and outreach plan that leverages technical work performed in the grant to build exciting new demos to be used in undergraduate and K-12 classroom settings. For example, a fruit-based energy harvesting system powering the developed low power tags which communicate directly with Wi-Fi devices will introduce students to the wonders of engineering in a pragmatic yet compelling way, with the hope of increasing diversity in science, technology, engineering, and mathematics (STEM)-related education environments. The proposed work specifically aims to enable the first practical low-power, low-cost integrated circuit solution which can enable a network of backscatter tags to connect with existing and Wi-Fi protocols. It would be the first to include a low-power universal-WiFi wake-up receiver for efficient synchronization and medium access control for the backscatter tags, and then backscatter Wi-Fi compliant signals piggybacked with IoT data. Importantly, the proposed backscatter platform will operate seamlessly with all existing Wi-Fi infrastructure so as to not interfere with existing spectrally-efficient productive communication.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.