EARS: Enabling Opportunistic Environmental Monitoring with Non-Uniform Sampling and Processing Circuits

该项目的最终愿景是帮助解决全球气候变化问题，这些问题已导致环境状况变得更加不可预测，并可能给人类社会带来可怕的后果。拟议的项目旨在通过不需要专用发射器或带宽的廉价频谱传感设备，为运行在专用射频(RF)频段的昂贵、复杂的监测设备提供替代解决方案。在美国，政府机构每年花费数十亿美元开发、维护和运营其遥感资产，但仍无法实现持续的环境监测。该项目应对持续和无处不在的全球环境监测的重大挑战，通过研究关键的使能技术，朝着众包的全球环境传感系统的愿景取得进展。同时，该项目计划将这项研究纳入K-12推广计划，并对本科生和研究生进行教育。研究成果将通过学术传播和教育视频与社区分享。这项研究的技术目标是通过一种新的射频传感模式实现机会性的环境监测，该模式利用主动和被动遥感的各个方面，以及低成本的按需频谱传感硬件和算法。传感硬件的目标是在100 MHz至5 GHz的广泛环境信号上提供机会信号(SOOP)反射测量。此外，由于所需功能的相似性，研究成果也适用于无线通信中的其他频谱感知挑战。智能的优点是通过应用程序、算法和硬件级别的创新展示环境监测方面的新能力。在应用层面，拟议的研究将利用自由的环境信号进行反射测量，使用从100 MHz(调频无线电)到5 GHz(WiFi)的SoOps，并在两者之间使用GPS/GNSS、军事通信卫星(MilComSat)、XM、LTE、GSM，以实现前所未有的对环境特性的按需感知。在硬件层面，灵活的接收器架构将利用非均匀采样(NUS)模数转换器(ADC)，该ADC可根据输入信号内容自动调整采样率。与现有设计相比，这可能会实现更高效的频谱感知硬件，因为只有在必要时才会生成样本。基于这种接收器架构，本项目将进一步探索新的NUS数字信号处理算法，直接对NUS-ADC输出的非均匀采样进行操作，从而避免了现有NUS设计中所需的耗电的内插电路。

The ultimate vision of this project is to help address global climate change issues, which have caused environmental conditions to become much less predictable with potentially dire consequences for the human society. The proposed project aims to provide an alternative solution to expensive, complex monitoring equipment operating in dedicated radio-frequency (RF) bands through inexpensive spectrum sensing equipment that requires no dedicated transmitters or bandwidth. In the US, government agencies spend billions of dollars every year to develop, maintain, and operate their remote sensing assets, but are still unable to achieve continuous environmental monitoring. This project addresses the Grand Challenge of continuous and ubiquitous global environmental monitoring, making progress towards the vision of a crowd-sourced, global environmental sensing system by investigating the key enabling technologies. Meanwhile, this project plans to integrate the research into K-12 outreach programs, and educate students at both the undergraduate and graduate levels. The research outcomes will be shared with the community via academic dissemination and educational videos.The technical objective of this research is to enable opportunistic environmental monitoring via a novel RF sensing modality exploiting aspects of active and passive remote sensing, as well as low-cost on-demand spectrum sensing hardware and algorithms. The sensing hardware aims to provide signal-of-opportunity (SoOp) reflectometry over a wide spectrum of ambient signals from 100 MHz to 5 GHz. In addition, the research outcomes are applicable to other spectrum sensing challenges in wireless communications due to the similarity of required functionalities. The intellectual merit is to demonstrate new capabilities in environmental monitoring via application, algorithm, and hardware level innovations. At the application level, the proposed research will leverage free ambient signals to perform reflectometry, using SoOps from 100MHz (FM radio) to 5GHz (WiFi) with GPS/GNSS, Military Communication Satellite (MilComSat), XM, LTE, GSM in between with the goal of unprecedented on-demand sensing of environmental properties. At the hardware level, an agile receiver architecture will leverage non-uniformly sampled (NUS) analog-to-digital converters (ADCs) that automatically adjust the sample rate depending on the input signal content. This potentially will enable more efficient spectrum sensing hardware relative to existing designs, as the samples are generated only when necessary. Based on this receiver architecture, this project will further explore novel NUS digital signal processing algorithms that operate directly on the non-uniform samples at the output of the NUS-ADC, thus avoiding the power-hungry interpolation circuitry required in existing NUS designs.