Date Added: Aug 2012
Highly accurate indoor localization of Smartphones is critical to enable novel location based features for users and businesses. In this paper, the authors first conduct an empirical investigation of the suitability of Wi-Fi localization for this purpose. They find that although reasonable accuracy can be achieved, significant errors (e.g., 6 - 8m) always exist. The root cause is the existence of distinct locations with similar signatures, which is a fundamental limit of pure Wi-Fi based methods. Inspired by high densities of Smartphones in public spaces, they propose a peer assisted localization approach to eliminate such large errors. It obtains accurate acoustic ranging estimates among peer phones, then maps their locations jointly against Wi-Fi signature map subjecting to ranging constraints.