Anchor-aided joint localization and synchronization using SOOP : theory and experiments

• Main Authors: Leng, Mei, Quitin, François, Tay, Wee Peng, Cheng, Chi, Gulam Razul, Sirajudeen, See, Samson Chong Meng
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2019
• Subjects: Geo-localization; Synchronization; DRNTU::Engineering::Electrical and electronic engineering
• Online Access: https://hdl.handle.net/10356/102678; http://hdl.handle.net/10220/47791
• Institution: Nanyang Technological University

We consider the problem of tracking a receiver using signals-of-opportunity (SOOPs) from beacons and a reference anchor with known positions and velocities, and where all devices have asynchronous local clocks or oscillators. We model the clock drift at individual devices by a two-state model with unknown clock offset and clock skew and analyze the biases introduced by clock asynchronism in the received signals. Based on an extended Kalman filter, we propose a sequential estimator to jointly track the receiver location, velocity, and its clock parameters using altitude information together with time-difference-of-arrival and frequency-difference-of-arrival measurements obtained from the SOOP samples collected by the receiver and a reference anchor. The receiver was implemented on a software-defined radio testbed, and field experiments are carried out using Iridium satellites as the SOOP beacons. The experiment and simulation results demonstrate that our measurement model has a good fit, and our proposed estimator can successfully track both the receiver location, velocity, and the relative clock offset and skew with respect to the reference anchor with good accuracy.