WiTraj: robust indoor motion tracking with WiFi signals - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue IEEE Transactions on Mobile Computing Année : 2022

WiTraj: robust indoor motion tracking with WiFi signals

Résumé

WiFi-based device-free motion tracking systems track persons without requiring them to carry any device. Existing work has explored signal parameters such as timeof-flight (ToF), angle-of-arrival (AoA), and Doppler-frequencyshift (DFS) extracted from WiFi channel state information (CSI) to locate and track people in a room. However, they are not robust due to unreliable estimation of signal parameters. ToF and AoA estimations are not accurate for current standardscompliant WiFi devices that typically have only two antennas and limited channel bandwidth. On the other hand, DFS can be extracted relatively easily on current devices but is susceptible to the high noise level and random phase offset in CSI measurement, which results in a speed-sign-ambiguity problem and renders ambiguous walking speeds. This paper proposes WiTraj, a device-free indoor motion tracking system using commodity WiFi devices. WiTraj improves tracking robustness from three aspects: 1) It significantly improves DFS estimation quality by using the ratio of the CSI from two antennas of each receiver, 2) To better track human walking, it leverages multiple receivers placed at different viewing angles to capture human walking and then intelligently combines the best views to achieve a robust trajectory reconstruction, and, 3) It differentiates walking from in-place activities, which are typically interleaved in daily life, so that non-walking activities do not cause tracking errors. Experiments show that WiTraj can significantly improve tracking accuracy in typical environments compared to existing DFS-based systems. Evaluations across 9 participants and 3 different environments show that the median tracking error < 2.5% for typical room-sized trajectories.
Fichier principal
Vignette du fichier
WiTraj_Robust_Indoor_Motion_Tracking_with_WiFi_Signals.pdf (20.13 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)

Dates et versions

hal-03548446 , version 1 (30-01-2022)

Identifiants

Citer

Dan Wu, Youwei Zeng, Ruiyang Gao, Shengjie Li, Yang Li, et al.. WiTraj: robust indoor motion tracking with WiFi signals. IEEE Transactions on Mobile Computing, 2022, 22 (05), pp.1-17. ⟨10.1109/TMC.2021.3133114⟩. ⟨hal-03548446⟩
90 Consultations
170 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More