  In recent years, with the development of the Global Navigation Satellite
System (GNSS), the satellite navigation technology has played a crucial role in
smartphone navigation. To solve the problem of the low positioning accuracy in
the smartphones based on GNSS, this paper proposes to apply real-time dynamic
carrier phase difference technique (RTK) in the smartphones, and a real-time
positioning system for smartphones based on RTK is implemented. This paper
presents the implementation and experimental results of this system. This
system is mainly composed of the GNSS reference station, the NTRIP system and
the smartphones. The experimental results show that the system effectively
improves the positioning accuracy of smartphones
