Vector Loop Transfer Functions and Noise Bandwidths

Abstract

This paper develops a transfer function formulation of the non-coherent vector tracking architecture for Global Navigation Satellite System receivers. From the transfer function model, a definition of vector loop noise bandwidths is introduced. Simulation results illustrate that vector noise bandwidths are functions of the carrier power to noise density, C/N0, of individual channels, the relative magnitudes of C/N0 across channels, and user-satellite geometry. This paper improves the understanding of the vector architecture by deriving its noise bandwidths and showing some noteworthy inherent features of the vector noise bandwidths with user-satellite geometry and C/N0. A preliminary analysis is also provided, which indicates that vector noise bandwidths have the potential to serve as useful metrics for designing scalar tracking loops with external Doppler aiding.