Joint Data-Pilot acquisition and tracking of Galileo E1 Open Service signal

Global Navigation Satellite Systems (GNSSs), such as the modernized Global Positioning System (GPS) and the ongoing European satellite navigation system Galileo, incorporate the new composite GNSS signals (e.g., Galileo E1 Open Service (OS) signal), which consist of two different components, the data and pilot channels. The existence of dual channel allows one to adopt special techniques to acquire and track these new signals. In this paper, the authors analyze the performance of three different implementation strategies, namely, i. Data-only, ii. Pilot-only, and iii. Joint Data-Pilot, for two different receiver modes: one with Sine Binary Offset Carrier (1,1) (SinBOC(1,1)) reference receiver, and the other one with Composite BOC (CBOC) reference receiver. All the simulations have been carried out in TUT Galileo E1 open source signal simulator, based on the most recent Galileo Signal-In-Space Interface Control Document (SIS-ICD). The simulation results show that acquisition with individual channel is not the best approach to acquire the signal as intuitively expected. Joint Data-Pilot channel combines all the significant power from data and pilot channels non-coherently that ultimately improves the signal detection around 2.8 dB, which has been verified via simulations in the context of the paper. Joint Data-Pilot channel also provides around 3 dB improvement over any individual channel in terms of tracking error variance. It will also be shown in the paper that the performance deterioration caused by using Sine BOC(1,1) reference receiver instead of CBOC reference receiver is negligible. Most of the findings based on data-pilot combination are as intuitively expected. However, the main novelty of the paper stays in presenting a realistic and detailed Simulink-based simulator for Galileo E1 signal that takes into account two receiver modes, and has already been made open access for research purpose.