ABSTRACT
This chapter proposes a cooperative location optimization scheme in a social network via crowd sensing. Specifically, the authors use neighborhood-based weighted least-squares estimation when relative distances between smartphones are available. The energy efficiency is achieved by sharing location information among co-located users and lower the global positioning system (GPS) update rate. Numerical and experimental results conclusively demonstrate that proposed cooperative localization schemes can achieve considerable performance gain in both indoor and outdoor environments. In terms of accuracy, GPS is preferred over its alternatives, especially in outdoor environments. However, GPS is extremely power hungry due to the inevitable complex computations. The authors organize: summarizes use cases and work on smartphone-based ranging; discusses system design; describes mathematical models, cooperative protocol, and the necessary condition for inter-node ranging; presents the Coloc scheme for the case that relative distances between smartphones in a neighbourhood; presents numerical results and experimental results, respectively.
