Galileo Signal Generation. Simulation Analysis

Abstract

This work presents the navigation signals and their allocation in the radio frequency band used in the new European Global Navigation Satellite System (GNSS): Galileo. All signals are described mathematically and then simulated using Matlab language (in transmission). Results are shown thus proving the theory provided by the European Space Agency document: “Open Service Signal in Space Interface Control Document” (OS SIS ICD). Before introducing the navigation signals, a deep study and analysis on the modulations and multiplexing schemes (Binary Phase Shift Keying(BPSK), Binary Offset Carrier (BOC), Alternate Binary Offset Carrier (AltBOC), Carrier Adaptative Sub-Carrier Modulation (CASM) and Double Binary Offset Carrier (DBOC) is carried out, also giving detailed results and simulations in Matlab proving the theory again. Moreover, the acquirement of both the autocorrelation function (ACF) and the power spectral density (PSD) of all navigation signals (in Matlab) and all modulations (in theory) is emphasised in the study. Ranging codes are also studied in this work, however from a more practical than scientific point of view, showing how they have been implemented and what type of codes they are (memory codes, based register codes, gold codes). Finally, a paper is provided reviewing the innovative aspects of the navigation signals and why these have been selected for this new GNSS.