Abstract:

The purpose of this work is to design a new algorithm for GNSS dual-frequency signals tracking, which is called the sum-diff joint tracking algorithm in this paper. The sum-diff joint tracking algorithm is based on the dual-frequency L1-assisted-L2 tracking method. The carrier sum-diff joint tracking algorithm can overcome the inherent shortcomings in traditional dual-frequency L1-assisted-L2 tracking method that the L2 signal tracking can get assistant information from the L1 signal tracking, but the L1 signal tracking cannot get any assistant information from the L2 signal tracking. The simulation results show that sum-diff joint tracking algorithm can couple dual-frequency signals in the carrier tracking loops and can make dual-frequency signals assist each other to achieve their tracking, and it significantly improves robustness and sensitivity in the GNSS dual-frequency signal tracking.

Key words: GNSS receiver, Dual-frequency signals, Combined tracking algorithm, High sensitivity