A Simple Way of Increasing Estimation Accuracy of Generalized Adaptive Notch Filters

Generalized adaptive notch filters are used for identification/tracking of quasi-periodically varying dynamic systems and can be considered an extension, to the system case, of classical adaptive notch filters. It is shown that frequency biases, which arise in generalized adaptive notch filtering algorithms, can be significantly reduced by incorporating in the adaptive loop an appropriately chosen decision delay. The resulting performance gains can be substantial. The proposed method can be used both in the system case and in the signal case.