Frequency acquisition and tracking in high dynamic environments

This paper presents mean squared error (MSE) analysis of two classes of fre quency acquisition and tracking algorithms. Additive white Gaussian noise a s well as Rician fading channels are considered, The class of batch-process ing algorithms is an extension of earlier least squares proposals used in m ore benign (lower dynamic) environments. These algorithms try to fit the ph ase trajectory of the down-converted samples of a received signal. Such a t rajectory will depend on the histories of both the signal and the local fre quency variations when the local frequency is updated recursively. We propo se a method to solve this difficulty and present both first-order and secon d-order recursive algorithms. Numerical results demonstrate that the MSE pe rformance predicted by our analysis is consistent with that estimated by co mputer simulation and that the proposed algorithms not only provide rapid a cquisition times but also give small tracking jitters.