Digital GNSS signal recorder, generator, and simulator for receiver test, qualification, and certification

The concept and the architectural design of a GNSS multisystem performance simulation environment are discussed. The proposed system allows simulating satellite constellations, generating digital signals, and replaying these signals for receiver performance analysis. For baseband receiver testing, verification, and comparison, the analog RFoutput of common GNSS signal generators has to be downconverted 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.