Publication Type

Conference Proceeding Article

Version

acceptedVersion

Publication Date

9-2015

Abstract

Indoor localization of mobile devices and tags has received much attention recently, with encouraging fine-grained localization results available with enough line-of-sight coverage and hardware infrastructure. Some of the most promising techniques analyze the time-of-arrival of incoming signals, but the limited bandwidth available to most wireless transmissions fundamentally constrains their resolution. Frequency-agile wireless networks utilize bandwidths of varying sizes and locations in a wireless band to effi- ciently share the wireless medium between users. ToneTrack is an indoor location system that achieves sub-meter accuracy with minimal hardware and antennas, by leveraging frequency-agile wireless networks to increase the effective bandwidth. Our novel signal combination algorithm combines time-of-arrival data from different transmissions as a mobile device hops across different channels, approaching time resolutions previously not possible with a single narrowband channel. ToneTrack’s novel channel combination and spectrum identification algorithms together with the triangle inequality scheme yield superior results even in non-line-ofsight scenarios with one to two walls separating client and APs and also in the case where the direct path from mobile client to an AP is completely blocked. We implement ToneTrack on the WARP hardware radio platform and use six of them served as APs to localize Wi-Fi clients in an indoor testbed over one floor of an office building. Experimental results show that ToneTrack can achieve a median 90 cm accuracy when 20 MHz bandwidth APs overhear three packets from adjacent channels

Keywords

Indoor Wireless Location, Time (Difference) of Arrival (ToA/TDoA), Channel Combination, CSI Combination, Bandwidth Increment, MUSIC Spectrum Identification, Time Synchronization, Distributed MIMO, Triangle Inequality

Discipline

Software Engineering

Research Areas

Software and Cyber-Physical Systems

Publication

MobiCom '15: Proceedings of the 21st Annual International Conference on Mobile Computing and Networking: Paris, September 7-11, 2015

First Page

537

Last Page

549

ISBN

9781450336192

Identifier

10.1145/2789168.2790125

Publisher

ACM

City or Country

New York

Additional URL

http://doi.org/10.1145/2789168.2790125

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