Digital GNSS PLL Design Conditioned on Thermal and Oscillator Phase Noise

Both thermal and oscillator phase noise pose significant difficulties for phase-lock loops (PLLs) in consumer grade GNSS receivers employing low quality oscillators. Unfortunately, these phenomena impose conflicting constraints on the PLL design and so a trade-off between noise rejection and tracking error must be made. Design rules are developed for optimal, Wiener filter based PLLs conditioned on the influence of the oscillator and thermal noise on consumer-grade receivers. The performance of these PLLs is examined through both simulation and the use of actual GPS signals.