Carrier Phase Tracking of Weak Signals Using Different Receiver Architectures

This paper investigates four receiver architectures and their ability to track the carrier phase signal under attenuated environments. The receiver architectures considered include a standard receiver, an estimator-based receiver, a vector-based receiver and an ultra-tight GPS/IMU receiver. The receiver architectures were implemented in software and tested using pedestrian-based data collected in open-sky environments but attenuated using a variable signal attenuator. To assess the performance of the different receivers, their phase lock indicator values and carrier phase-based positioning quality were compared. Unexpectedly, the vector-based receiver did not perform very well and more work is needed to understand why this is the case. Of the remaining receivers, the ultra-tight receiver performed best, the estimator-based receiver performed second best and the standard receiver performed the worst. The ultra-tight receiver provided about 7 dB and 3 dB of sensitivity improvement over the standard and estimator-based receivers.