Application of an Adaptive UKF in the Frequency Offset Estimation of OFDM with Colored Noise

OFDM system is sensitive to the frequency offset, by which the orthogonality will be destroyed between the sub-carriers and the Inter-Carrier Interference (ICI) will be generated. Considered that the colored noise is often studied in the dynamic data processing, an adaptive Unscented Kalman Filter (UKF) is presented to estimate and eliminate the frequency offset in this paper. Adaptive factors are introduced into the iteration of the state variance and the noise variance to inhibit the misalignment in the filtering caused by the correlation of the noise. The results of simulation show favorable estimation of the frequency offset, as well as the smoothing effect of the adaptive UKF, which is the evidence of the strong tracking effect of the proposed algorithm.

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