STARx A GPU Based Multi-System Full-Band Real-Time GNSS Software Receiver

As the construction and modernization of global navigation satellite systems (GNSS), in the near future, the four main navigation systems (GPS, BDS, GLONASS and GALILEO) as well as some regional systems such as QZSS and IRNSS will broadcast many signals in different frequency. Some of the signals may need further adjustment. In interim, the traditional hardware GNSS receivers which have high integration density and low flexibility are not suited for signals monitoring especially for those new signals. In order to meet the requirement of monitoring GNSS signals as well as the joint processing of them, a high-flexibility multi-system full-band real-time GNSS software receiver is developed. In addition to a wideband antenna, a RF front-end and a data acquisition card to fulfill down-conversion and AD conversion, the rest of receiver are implemented in an ordinary PC with a GPU. With efficient acquisition and tracking methods, the proposal receiver can process all of the civil signals from four main GNSS and some of the regional systems in real-time, including GPS L1C/A, L2C, L5, L1C, BDS B1, B2, GLONASS Gl, G2, GALILEO ElOS, E5a, E5b, QZSS L1C/A, L2C, L5, and L1C signals. Based on the software architecture, the receiver can provide PVT results, measurement results, and many intermediate data such as correlator outputs and raw bit stream which are necessary for signals monitoring and performance analysis. Meanwhile, the strong flexibility of this receiver makes it easy to expansion and update in the future. The GLONASS modernized signals as well as BDS Phase III signals can be quickly added to current receiver after the release of their interface control document (ICD). By using the proposed software receiver, this paper presents the real-time tracking states of all civil signals, the positioning results of each navigation signal, and the monitoring results of viable GNSS satellites. Finally, since the receiver can handle all the civil GNSS signals in real-time and has a flexible structure, it can be used as a dedicated development platform for various types of navigation research.