Weak Satellite Signal Tracking Loop Based on Traditional Tracking Framework

Abstract

Global Satellite Navigation System (GNSS) is applied widely in many fields nowadays, but is still quite limited under complex signal environments, especially weak signal situation. And the major limitation comes from the signal tracking algorithm in GNSS receiver. To solve this problem, this paper mainly deals with performance enhancement for traditional tracking framework. By inviting definition of digital equivalent bandwidth and analyzing sensitivity and stability, this framework is deeply discussed, and the relationship between correlation time and loop bandwidth setting becomes clearer. Based on this foundation, an adaptive tracking algorithm is proposed with longer correlation time under vibrated signal attenuation situation, via statistical learning of carrier phase discriminator outputs. Experiments demonstrate that our proposed algorithm outweighs the traditional one with more gain of sensitivity and stable adaptation under attenuated data situation.