GPS Localization Improvement of Smartphones Using Built-in Sensors

Location awareness and navigation are becoming one of the most important features in mobile phones and smartphones. Personal navigation and location based services are enlarging the scope of mobile applications. GPS is the most efficient positioning technology. Thanks to the reduction in the size of the GPS receivers and the integration of GPS with mobile phones, GPS is one of the most important service providers in LBS. By the way, since mobile phones and smartphones usually have relatively low cost GPS chips, the performance of locating accuracy is highly dependent on environmental factors. In addition, the accuracy of GPS varies depending on the number of GPS satellites and is reduced in GPS interfering spots such as in a forest or around buildings. This paper proposes a localization improvement algorithm in GPS interfering spots by integrating information of multiple sensors in smartphones. The proposed algorithm is implemented in a smartphone and the performance is evaluated on a campus. The proposed algorithm has better performance than only the GPS location information in GPS interfering spots and maintains reasonable performance in open spaces where the GPS receiver is accurate.