Abstract
The research described by this thesis was undertaken at a very timely moment in the development of global navigation satellite systems (GNSS). During the course of this work the signal structure of an entirely new generation of GNSS signals was been defined. The first satellites producing a new range of different coding and modulation schemes have been launched, initiating the modernisation of the American GPS and the introduction of the European Galileo system. An important aspect of the new signal structure for both GPS modernisation and Galileo is an entirely new kind of modulation called BOC (Binary Offset Carrier). Despite certain advantages this modulation comes with the notorious characteristic of a multi-peaked correlation function. In our view all known receivers, or receiver principles, have problems with this: either because the receiver is not fail safe and is potentially unreliable (the so-called bump-jumping receiver); or the multi-peaks are eliminated at the very substantial cost in much degraded accuracy. During my research under Dr Hodgart what seems to be an entirely new and original method has been developed which entirely solves the problem of tracking BOC. The problem of multi-peaks goes away and there is no loss of potential accuracy. This thesis describes in detail this invention and the first experimental results. This research was carried out at the University of Surrey under the joint supervision of Surrey Space Centre and Surrey Satellite Technology Ltd. Shortly before this work began SSTL achieved a contract to design and build the first ever test satellite (Giove- A) of the Galileo signals and technology. This research contributed to the design and manufacture of a Galileo signal generator which was flown on-board the satellite (launched December 2005). Expanding upon SSTL's existing designs this work enabled the design and creation appropriate receivers to monitor the transmissions both in ground based emulations and real live tests after launch. These designs are intended to be the core of future SSTL space receivers. This thesis describes in detail the creation of both transmitter and receiver architectures for the testing and evaluation of GNSS signals.