Improved Real Time GPS RF Data Capturing for GNSS SDR Applications

Abstract

Global Navigation Satellite System (GNSS) software-defined radio (SDR) is a programmable software receiver, primarily used to receive satellite data and provide user position. It is flexible and cost-effective compared to conventional satellite receivers. In GNSS SDR, recording the live raw data in real-time is a challenging task as large data are sent by the satellites at a very high speed. These data are further processed by the baseband algorithms which provide the user location. The accuracy of the tracked location depends on the precision of the data captured. Among the available hardware receivers, USRP RF front end kit provides flexibility. This paper proposes an efficient approach to capture the real-time GPS data by using the USRP N210 kit. If the receiver is not tuned with the exact parameters, the problems of data overflow and underflow occur. A novel data controlling queue thread method is introduced to overcome this problem. It is evident that the results obtained from our method are very close to those of Ublox GPS.