An Adaptive Adjustment Technique for Quadrature Modulators

摘要

Modern digital mobile communication systems often use quadrature techniques to implement the desired signal modulation. Analog quadrature modulators have three major impairments, namely: gain imbalance, phase imbalance and dc-offsets. In this paper we presume the error model of analog quadrature modulators and analyze the effects of quadrature modulators (QM) imperfection. An adaptive adjustment digital technique is presented for compensation of these modulators impairments. Simulation results show that the adaptive adjustment algorithm is very effective.