BikeLoc: a Real-time High-Precision Bicycle Localization System Using Synthetic Aperture Radar Hongjiang Lyu, Linghe Kong, Chengzhang Li Yunxin Liu, Jiansong Zhang, Guihai Chen 2017.8.3 APNet 2017

Development of Smart Bicycles

Why not GPS? GPS's error is at meters level. It performs poorly under tall buildings and in the tunnel.

1 2 3 Requirements for Bicycle Localization System Portablility Little power consumption 2 Online algorithm 3

A new bicycle localization system Related works: S. Kumar, S. Gil, D. Katabi, and D. Rus. Accurate indoor localization with zero start-up cost. MobiCom, 2014. J. Xiong and K. Jamieson. Arraytrack: A fine-grained indoor location system. NSDI, 2013. S. Nirjon, J. Liu, G. DeJean, B. Priyantha, Y. Jin, and T. Hart. Coin-gps: indoor localization from direct gps receiving. MobiSys, 2014. BikeLoc:

Overview of BikeLoc 1 2 Take Channel State Information (CSI) snapshots Performing Circular Synthetic Aperture Radar 2 Determine the direction of APs 3

Theoretical Part Circular Synthetic Aperture Radar Wireless Channels Relative Power Relative Power

Theoretical Part Obstacle Circular Synthetic Aperture Radar Wireless Channels Relative Power Relative Power

Theoretical Part Extending to Three Dimensions Relative Power

Design of BikeLoc Position of the APs Direction of APs z Position of the APs x y Direction of APs Motion Sensor Localization Height of the wheel Real-time Localization Position of the wheel Starting point Middle point Current point

Design of BikeLoc

Why Wheel? We use Circular Synthetic Aperture Radar (CSAR). CSAR is tansition-resilient.

Hardware Prototype of BikeLoc Laptop Mobike Antennas Gyroscope

Relative power among different Experimental Results Relative power among different azimuthal and polar angle with antenna pairs: A1A2, A1A3, A2A3 and Sum of them. A2 A1 A3 Accuracy: 1.5° A1A2 Sum A2A3 A1A3

Angle-Of-Arrival Estimation Accuracy AOA Estimation of Different Antenna Pairs:

Localization Accuracy Localization Accuracy Against Number of APs:

Localization Accuracy Error in Distance of Motion Sensor Localization：

Conclusion We design BikeLoc, a novel design to enable accurate bicycle localization based on a subtle combination of the wheel and WiFi devices. We implement a prototype of BikeLoc. In our testbed, we showed that BikeLoc is very promising to achieve tens of centimeters level localization accuracy.

Q&A 19