HiMLoc: Indoor smartphone localization via activity aware Pedestrian Dead Reckoning with selective crowdsourced WiFi fingerprinting

The large number of applications that rely on indoor positioning encourages more advancement in this field. Smartphones are becoming a common presence in our daily life, so taking advantage of their sensors can help to provide ubiquitous positioning solution. We propose HiMLoc, a novel solution that synergistically uses Pedestrian Dead Reckoning (PDR) and WiFi fingerprinting to exploit their positive aspects and limit the impact of their negative aspects. Specifically, HiMLoc combines location tracking and activity recognition using inertial sensors on mobile devices with location-specific weighted assistance from a crowd-sourced WiFi fingerprinting system via a particle filter. By using just the most common sensors available on the large majority of smartphones (accelerometer, compass, and WiFi card) and offering an easily deployable method (requiring just the locations of stairs, elevators, corners and entrances), HiMLoc is shown to achieve median accuracies lower than 3 meters in most cases.