This master thesis is a research project, in the field of Global Navigation Satellite Systems, focused on joint estimation of time of arrival of direct and reflected signal, for improving the user positioning. The purpose is to investigate if, and the degree in which, different joint estimation methods can outperform the tracking loops already implemented in the conventional receivers.
The maximum likelihood estimator will be investigated and implemented. Due to the computational complexity of the maximum likelihood estimation, signal compression techniques will be used. Different constraints will be proposed and developed.
For evaluation of the solutions, a simulation platform will be developed, which will be used for generating the direct and reflected signals and also for implementing the maximum likelihood algorithm. The performance of estimator in multipath environments will be compared with the classical tracking loops.