Digital Equalization of a Polyphase Harmonic Mixer

A mathematical framework is developed for the harmonic distortion problem. This formulation has interesting analogies to well-studied problems in array processing and multiuser detection. Based on this framework, a minimum mean squared error equalizer is first derived. By exploiting the unique structure of the signature vectors, a noniterative low-complexity blind equalizer is proposed. Existing harmonic rejection approaches are analyzed within this framework. The proposed equalizer can be shown to significantly outperform existing approaches in the presence of large interferers.