(State Key Laboratory for Novel Software Technology,Nanjing University, Nanjing210023,P.R.China)
Abstract: Localization technology is the cornerstone of location based services (LBS). This paper presents the design and implementation of a localization system called IU which is based on WiFi signal strength measurement and smartphone’s inertial sensors. IU utilizes the novel propagation model UAF to predict RSS values not only for every location but also for every orientation of each location. This makes it possible to detect whether APs are shielded by user body and compensate the user attenuation factor in generated values. IU also detects user’s orientation with smartphone’s inertial sensors and then preselect a subset of the predicted data. While prior systems didn’t consider the user body blocking effect, IU does a better simulation about the real-world environment, the blocking effect is thus invisible in the localization phase. Experiments show that IU does achieve a better localization accuracy than previous systems.Keywords:Indoor localization, Smartphone, WiFi propagation model, Sensor fusion, Location based services

Biographies:
　　YANG Hao is a graduate student inDepartment of Computer Science of Nanjing University, Nanjing, China.His research interest lies in WiFi localization system and sensor fusion.
　　Chen Li-jun is a professor in Department of Computer Science of Nanjing University, Nanjing, China. His research interests include internet of things system and test methods.