Publications
CONFERENCE (INTERNATIONAL) Orientation Estimation using Differences in WiFi Signal Behavior in LOS and NLOS Cases
Jiaqing Yang (Ritsumeikan University), Kota Tsubouchi, Shoma Nakamae (Ritsumeikan University), Nobuhiko Nishio (Ritsumeikan University)
The 22nd International Conference on Pervasive Computing and Communications (PerCom 2024)
April 22, 2024
Accurate orientation information is essential for calibrating pedestrian dead reckoning (PDR) systems, which determine a user's position based on accelerometer and gyroscope data. Calibrating PDR helps mitigate cumulative errors during navigation, but previous methods have struggled to correct errors in body rotation direction using gyro sensors. Traditional approaches, such as magnetic compasses, are impractical indoors due to interference. Instead, this paper proposes a unique technique that uses readily available smartphone data—Received Signal Strength Indicator (RSSI) and Round-Trip-Time (RTT)-based distance measurements. The core principle is that RSSI is influenced by obstacles and user presence (non-line-of-sight or NLOS conditions), while RTT-based distances remain more stable. By accurately measuring distances and estimating expected signal strengths, the method distinguishes between line-of-sight (LOS) and NLOS conditions. Field tests confirm the method's efficacy, achieving a remarkable 90\% accuracy in estimating WiFi-AP direction. This innovative approach contributes to addressing cumulative errors in smartphone-based navigation without relying on specialized equipment.
Paper :
Orientation Estimation using Differences in WiFi Signal Behavior in LOS and NLOS Cases
(external link)