Measuring Time-Varying $I/Q$ Impairments in Digital Transmitters

摘要: Impairments affecting the baseband modulator of digital transmitters, which are commonly called I/Q impairments, responsible for deviations symbols from their original position on diagram. They cause a reduction in noise margin and ultimately worsen probability error. This is why measurement so important all stages life cycle transmitters. paper presents an method evaluation impairments based discrete extended Kalman filter (DEKF). In same way as alternative solutions already presented literature, exhibits good performance presence time-invariant impairments. Differently them, it allows accurate measurements time-varying thus making real-time tracking evolution feasible. After few theoretical notes DEKF, operative proposed described detail. Several experiments then conducted radio frequency signals to assess method; obtained results given discussed.