ORUS Galileo/GPS Open Receiver

Franck Benghouzi, Jose Perello Gisbert and Jean-Luc Issler

Abstract:	ORUS (Open Receiver for Upgraded Services) is a complete hardware/software environment for modeling and processing Satellite RadioNavigation signal processing chains and characterising and processing GNSS broadcast signals (SIS). ORUS allows the user to model the different functions of RadioNavigation receivers (present and modernized GPS, future Galileo signals). This is done by means of a modular and hierarchised architecture (open receiver) and associated HW/SW modules library dedicated to Radionavigation signals processing. In addition, a dedicated interface allows the user to acquire and store real digitalized signals up to 2 Gbits/s into N hardware disks with a whole capacity of 546 Gbytes (around 35 minutes of storage with 8 bits of quantization). The modeling and processing environment offers a user friendly interface describing the system architecture. A multi-window graphical environment allows the user to visualize the model « vertical » hierarchy and offers a functional decomposition of the tool (modeling window, simulation window, monitoring window, and library). The software environment provides a component library and specific modules for RadioNavigation signal processing chains (GPS, EGNOS, Galileo) from the higher level (test-bed, complete receivers) to the lower level (shift registers, Look-up tables, etc.) including intermediate modules (signal generators, signal processing modules, etc.). A generic hardware component library (VHDL code to be implemented in the ORUS HW board) is also available to implement the high-rate processing functions (supporting in particular the BPSK/QPSK/BOC/AltBOC modulations processing) for fast simulations or real-time processing of digitalized signals. ORUS intends to support the Satellite RadioNavigation community (Research labs, Institutions, Universities, Service providers) to model and simulate the Radionavigation processing chain at different levels depending on their objectives. The envisaged applications are therefore: Training models applied to existing RadioNavigation systems, Performance assessment for new signals or systems, innovative receiver architecture, R&D: Innovative algorithms design & Calibration, Radionavigation application development: Quality Of Service validation. Today, HW/SW models are available to process GPS and Galileo signals at different C/N0 levels including the processing of the PRS signals. The ORUS environment has already been used by ESA and CNES (French Space Agency) to acquire and store GIOVE-A signals at 2Gbits/s. ESA has processed the recorded GIOVE-A signals with ORUS in the L1, E5 and E6 bands. In addition, the DGA (French Ministry of Defence) has been used the simulation features of ORUS to assess the Galileo PRS signal characteristics (robustness to interferences). ENAC has also been using ORUS for a student project on the tracking loop filters. The paper intends to present the architecture of ORUS, the existing models to process the GSVF/GIOVE-A signals and the results obtained.
Published in:	Proceedings of the 20th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2007) September 25 - 28, 2007 Fort Worth Convention Center Fort Worth, TX
Pages:	1049 - 1053
Cite this article:	Benghouzi, Franck, Gisbert, Jose Perello, Issler, Jean-Luc, "ORUS Galileo/GPS Open Receiver," Proceedings of the 20th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2007), Fort Worth, TX, September 2007, pp. 1049-1053.
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