Widar: Decimeter-level passive tracking via velocity monitoring with commodity Wi-Fi

Kun Qian, Chenshu Wu, Zheng Yang, Yunhao Liu, Kyle Jamieson

Research output: Chapter in Book/Report/Conference proceedingConference contribution

269 Scopus citations

Abstract

Various pioneering approaches have been proposed for Wi-Fi-based sensing, which usually employ learning-based techniques to seek appropriate statistical features, yet do not support precise tracking without prior training. Thus to advance passive sensing, the ability to track fine-grained human mobility information acts as a key enabler. In this paper, we propose Widar, a Wi-Fi-based tracking system that simultaneously estimates a human's moving velocity (both speed and direction) and location at a decimeter level. Instead of applying statistical learning techniques, Widar builds a theoretical model that geometrically quantifies the relationships between CSI dynamics and the user's location and velocity. On this basis, we propose novel techniques to identify frequency components related to human motion from noisy CSI readings and then derive a user's location in addition to velocity. We implement Widar on commercial Wi-Fi devices and validate its performance in real environments. Our results show that Widar achieves decimeter-level accuracy, with a median location error of 25 cm given initial positions and 38 cm without them and a median relative velocity error of 13%.

Original languageEnglish (US)
Title of host publicationMobiHoc 2017 - Proceedings of the 18th ACM International Symposium on Mobile Ad Hoc Networking and Computing
PublisherAssociation for Computing Machinery
ISBN (Electronic)9781450349123
DOIs
StatePublished - Jul 10 2017
Event18th ACM International Symposium on Mobile Ad Hoc Networking and Computing, MobiHoc 2017 - Chennai, India
Duration: Jul 10 2017 → …

Publication series

NameProceedings of the International Symposium on Mobile Ad Hoc Networking and Computing (MobiHoc)
VolumePart F129153

Other

Other18th ACM International Symposium on Mobile Ad Hoc Networking and Computing, MobiHoc 2017
Country/TerritoryIndia
CityChennai
Period7/10/17 → …

All Science Journal Classification (ASJC) codes

  • Hardware and Architecture
  • Computer Networks and Communications
  • Software

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