Robustness techniques for global navigation satellite systems (GNSS) receivers =TECHNIQUES DE ROBUSTESSE DES RÉCEPTEURS POUR LES SYSTÈMES GLOBAUX DE NAVIGATION SATELLITAIRE (GNSS)

摘要

The world of satellite navigation has known a constant evolution for several years. At the turn of the century, its craze resulted in a multitude of automated applications being released in both the commercial and industrial markets. All this occurred in areas as diverse as agriculture, construction, security and transport of all kinds. Through integration with complementary technologies and ever smaller achieved accuracy thresholds, geopositioning also managed to break through initially incompatible markets, such as hostile environments and confined spaces (e.g. in urban canyons, inside buildings, under the canopy, etc.). Indeed, recent technological and algorithmic advances can now mitigate or solve the traditional limitations of GPS, namely availability, integrity, accuracy and resistance to interference.;With so much variety and changes, a universal and flexible approach is best suited as a basic structure of a satellite navigation receiver. The work herein therefore focuses on universal architectures for such channels, through various hardware modules forming the receiver. Although indispensable, upstream radio frequency modules and downstream software in navigation receivers are beyond the scope of this thesis.;Following a comprehensive review of the specificities of each satellite signal, a list of their associated tracking techniques is classified. This information sets the stage for the architecture requirements of the targeted universal channels, which are broken up into three and divided into as many papers: 1) frequency domain acquisition, 2) match filter tracking and 3) solution augmentation with differential corrections. Various analyses and receiver configuration tools enabling a flexible and efficient development platform are then presented, including the decoding of navigation messages, different approaches to compute the signal to noise ratio and the quantification level of the incoming signal.;Since the project is ambitious, validation is based on experimentation with real signals, thus avoiding the additional development of complex multifrequency simulators for different constellations. Impacts and benefits of this patent-rewarded research are considerable, especially with the exponential growth of the market for mobile and wearable electronics.;The thesis opens with a renewed old problem, namely the signal selection (rather than the satellite selection). It is revived by leveraging the universal channels to minimize the acquisition time with old signals, while maximizing the robustness of the solution by the gradual transition to modernized and new signals. In addition, this channel flexibility paves the way for cognitive and tactical receivers, enabling them to adapt to their environment or frequency conditions.