Snapshot Software Receiver for GNSS in Weak Signal Environments: An Innovative Approach for Galileo E5

Global Navigation Satellite System (GNSS) positioning has turned out to be an enabler of Location-Based Services (LBS). This has motivated in recent years an increasing research activity on signal processing techniques for GNSS receivers. However, one main limitation faced by these GNSS receivers is the propagation of GNSS signals in complex scenarios such as urban canyons and indoor, where signals suffer from high attenuation, severe multipath, near-far problem and non-Line Of Sight (LOS) propagation. These limitations have given rise to highly specialized GNSS receiver architectures, such as snapshot or one shot, overcoming the computational cost of the required processing algorithms and allowing manufacturers the integration of GNSS receivers in mobile platforms. They are commonly known as High Sensitivity GNSS (HSGNSS) receivers [8]. The European Galileo system will provide additional signals for usage and will most likely improve overall GNSS-based positioning, as well as the role of GNSS technology as an LBS enabler. Research on highsensitivity Galileo receivers has been quite limited so far; therefore an extensive research activity is necessary. Some effort on E1bc signals has been done, but E5 has not been sufficiently explored [1]. A higher bandwidth and the possibility of using two signals are an advantage in terms of performance in urban canyons or indoor. Nevertheless, a higher bandwidth translates in a higher sampling rate and computational load. The objective of this work focuses on the design, implementation and performance evaluation of a snapshot software receiver system that exploits the properties of Galileo E5 pilot signals to detect very weak signals, offering a simple yet efficient acquisition-based receiver. The design is based on an acquisition stage that uses efficient signal processing techniques to deliver delay- Doppler estimates and can lead to a position fix without requiring a tracking stage.Space EngineeringAerospace Engineerin