Low-Power Communication for Environmental Sensing Systems

Abstract

Over the last decade, the Internet of Things (IoT) has been changing the world, from enabling connected electronics, smart homes, to smart agriculture. Today, IoT systems have the potential to make a significant impact when it comes to environmental monitoring, which has become increasingly relevant in the times of the climate change crisis and the need to achieve biodiversity conservation. Imagine being able to use passive wireless communication and deploying battery-less sensors for remote environmental monitoring. This dissertation aims to advance and empower these efforts and presents new methods of low-power wireless communication and sensing systems. First, I introduce FarmBeats, an IoT system for data driven agriculture that solves key challenges related to power, connectivity, and cost. Next, I discuss low-power downlink solutions for ambient backscatter systems. In particular, Wireless Quantization Index Modulation and 'Glaze', which build upon data-hiding techniques to enable downlink communication using existing infrastructure and occupied RF spectrum. Lastly, I present Modulated Johnson noise, a new wireless communication system that uses Johnson noise to enable very low-power wireless communication.