A new phase and frequency offset estimation algorithm for OFDM systems applying Kalman filter

In this paper the frequency offset problem in OFDM is addressed. An unknown frequency offset causes per subcarrier amplitude distortion, ICI and phase rotation. In coherent communication accurate frequency as well as phase estimates are required. The estimators are obtained by Kalman filtering, where a frequency domain approach is used. The Kalman filter derived has a structure of a combined phase and frequency tracking loop. The estimator outperforms conventional reported methods, has fast convergence and good tracking ability. Regarding the complexity of the algorithm, the current Kalman filter requires at most 2×2 matrix inversions.