On the robustness of a widely nonlinear approach to model impairments in I/Q modulators

This communication compares several approaches to model impairments in I/Q modulators. The proposed widely nonlinear model is designed to deal with improper signals, and its structure is simplified by using compressive-sensing techniques. The different approaches are tested with a 15-MHz LTE signal obtained from a commercial vector signal generator operating under diverse built-in artificial impairment settings. The modeled signals show that the proposed approach is inexpensive in terms of complexity, robust under a wide range of impairments, and it outperforms the other alternatives in terms of the normalized mean square error and the spectrum of the error signal.