ipexSR: A real-time multi-frequency software GNSS receiver

Today's Global Navigation Satellite System (GNSS) receivers predominantly utilize hardware based digital signal processing. This approach generally provides high performance and low power consumption GNSS receivers but on the other hand limits the flexibility as the receiver functionality is fixed. The aim of this paper is to present an overview on the ipexSR real-time GNSS software receiver developed at the Institute of Geodesy and Navigation at the University FAF. The receiver does all signal processing in software and therefore is conceptually well suited for many applications which for example may benefit from additional data, utilize different interfaces or have a need for customized integration depth. Starting with an overview of the receiver architecture and signal processing chain some features of the ipexSR are presented. To give an indication of the capabilities of software receiver technology several applications including GNSS signal monitoring and assisted GNSS techniques are presented afterwards. The paper closes with current developments like implementation of a vector tracking loop or the capability to utilize the new Galileo AltBOC signal.