Complex adaptive notch filter structure for tracking multiple complex sinusoidal signals

A new type of complex adaptive notch filter is developed, which is capable of tracking multiple complex sinusoidal signals. The proposed complex structure is developed from an all-pass design based on a structurally lossless prototype, which is canonic in the number of multipliers and delay elements. The learning algorithm is based upon output error calculation, and is better matched for tracking closely located signal frequencies than a recently introduced approach of Regalia.