A New Multipath and Noise Mitigation Technique Using Data / Data-less Navigation Signals

Modernized GPS and Galileo will be available to civil users at the end of this decade. Their signal structure design will bring tremendous improvement for any user compared to current GPS. One important advance, which is the focus of this paper, is the availability of data and pilot (or data-less) channels wrapped in a Quadrature Phase Shift Keying (QPSK) modulation (or similar). The presence of a pilot channel will allow for a more effective tracking of the carrier, bringing lower loss of lock threshold, better resistance to dynamics, and better carrier aiding. A new method, using both the data and pilot channel is developed herein that reduces the noise of the carrier-phase estimation while keeping the excellent performance of coherent carrier tracking. The use of a more reliable and accurate Phase Lock Loop (PLL) allows for longer integrations that can significantly aid the Delay Lock Loop (DLL) in mitigating thermal noise in case of a low signal-to-noise ratio. This possibility can also be used to integrate multipath mitigation techniques that usually have a lower resistance to ambient noise. A method using the High Resolution Correlator technique on the pilot channel and a Narrow CorrelatorTM technique on the data pilot is investigated. It shows excellent resistance to noise and multipath, while being very robust. Finally the combination of the two carrier phase and code delay tracking using the data and pilot channels is tested in different environments including the presence of strong multipath. Static and kinematic users are simulated as well.