Robustification of the self-optimizing narrowband interference canceler - extremum seeking in complex domain

Self Optimizing Narrowband Interference Canceller (SONIC) is a novel active disturbance rejection algorithm which combines the gain-freezing technique and automatic adjustment of a complex-valued estimation gain. In the paper a new version of the self-adjustment mechanism, based on the extremum-seeking technique, is proposed. To preserve the compactness of the original controller, the adaptation algorithm is designed to operate in complex domain. The resulting adaptive controller is much more robust than its previous variant.