GNSS constellation simulator and digital signal generator for receiver test, qualification and certification

This paper presents the overall concept and architectural design of a deterministic GNSS Constellation Simulator and Digital Signal Generator. For baseband receiver testing, verification, and comparison, the analog RF-output of common global navigation satellite system (GNSS) signal generators has to be down-converted and digitized first. The omnipresent white Gaussian noise within this process destroys the required controllability of the simulation environment since every time the process is restarted another set of Gaussian noise is added to the signal samples. With respect to the low power of the GNSS signals this is a considerable drawback in the simulation process. In contrast, the presented solution can be used as a deterministic digital GNSS generator with exactly reproducible digital samples. Moreover real-world data can be recorded and replayed in the same accurate way. This considerably improves the development, qualification, and certification process.