mm-Wave Radar for Touchless Interaction: from Soli Concept to Pixel 4

Google’s Pixel 4 launched in fall 2019 with the first radar ever integrated into a smartphone, enabling gesture and presence sensing for new modes of user interaction. These sensing capabilities are powered by Soli, a miniaturized radar system designed and developed specifically for touchless interaction at Google Advanced Technology and Projects (ATAP). In this talk, we discuss Soli’s development and productization path, from concept to core R&D to integration into Pixel 4. We highlight the tightly intertwined co-design of core radar technology, algorithms, and interaction design in Soli’s development, driven by requirements for a ubiquitous and scalable human sensing technology. We also discuss some of Soli’s new approaches and innovations in radar systems, signal processing, machine learning, and interaction design in order to enable a new modality for sensory perception. In the second part of the talk, we cover some of the technical challenges faced in integrating Soli radar into the Pixel 4 smartphone, including chip size and placement, power consumption, and interference. We discuss how our cross-disciplinary approaches to these challenges ultimately enabled Soli to successfully ship in the phone. Finally, we close with future-looking directions for radar in consumer devices. By capturing the sensitivity and precision of human movements in everyday user interfaces, we believe scalable mm-wave technology has the potential to revolutionize the way we interact with technology.