Phase-and-rate Feedback Loops for Weak GNSS Signals Tracking

With the transfer function of rate-only feedback loop and phase-and-rate feedback loop,the relationship between loop stability and the product of pre-correlation time and equivalent noise bandwidth will be analyzed.Then realizable phase-and-rate feedback loops for software and hardware receivers will be introduced.Finally,some tracking results of real signals will be given.Simulation results show that software receivers perform well with phase-and-rate feedback loops and longer pre-correlation time when carrier-to-noise ratio(CNR) of received signals is approach to 15 dB×Hz.