Fuzzy Phase-Locked Loops

Document Type

Conference Proceeding

Publication Date


Publication Title

IEEE Position, Location and Navigation Symposium


The problem of robust phase-locked loop (PLL) design has attracted attention for many years, particularly since the advent of the Global Positioning System. This paper proposes and demonstrates the use of a fuzzy PLL to estimate the time-varying phase of a sinusoidal signal. It is shown via simulation results that fuzzy PLLs offer performance comparable to analytically derived PLLs (e.g., Kalman filters and H estimators) when the phase exhibits high dynamics and high noise. The fuzzy PLL rules are optimized using a gradient descent method and a genetic algorithm

Original Citation

D. Simon and H. El-Sherief. (1994). Fuzzy Phase-Locked Loops. IEEE Position, Location and Navigation Symposium, Las Vegas, 252-259, doi: 10.1109/PLANS.1994.303321.