IQ-imbalance and its compensation for non-ideal analog receivers comprising frequency-selective components

[摘要] Within current implementations of mobile terminals, more and moreanalog components are replaced by appropriate digital processing.On the one hand, the analog front-ends become less complex. On theother hand, more digital signal processing is required tocompensate for the spurious effects of the front-end. In thisarticle, the frequency-selective imbalance of the in-phase andquadrature-phase signals is addressed. A closed representation ofarbitrary signals being processed by an arbitrary imbalancedanalog front-end is provided. The analysis is valid for both,direct conversion and intermediate frequency (IF) reception. Withthe consideration of practical variations of amplitude and phaseimpairments, the influence of only the frequency-dependentportions of the impairments is investigated. It is shown, that thecompensation of the quasi-linear impairments is sufficient andcomplex deconvolutive IQ-regeneration procedures are notstringently required to obtain sufficient signal qualities.

[学科分类] 电子、光学、磁材料