Frequency acquisition and tracking for mobile LEO satellite communications

A class of recursive frequency acquisition and tracking algorithms for use in high dynamic mobile low Earth orbit (LEO) satellite communication systems is proposed. The underlying principle of these algorithms is to apply the least-squares method to the reconstructed phase trajectories to estimate and predict the received frequency variations (Doppler frequency, Doppler rate, etc.). We consider both additive white Gaussian noise (AWGN) and Rician fading channels and analyze the corresponding mean squared errors (MSE). The numerical performance of the proposed algorithms demonstrates that the new frequency tracking algorithms not only has rapid acquisition times but also gives smaller tracking jitters.