A Novel Blind Compensation Scheme for I/Q Imbalance of Wideband Zero-IF Transmitter

In the wideband wireless systems, the frequency-dependent I/Q imbalance is a severe impairment which decreases the communication quality. We propose a blind calibration scheme for compensating the I/Q imbalance in transmitters. The parameter estimation makes use of the second-order statistics of the signals. And a closed-form solution is obtained. The compensation structure consists of two parts, corresponding to the frequency-dependent imbalance and the frequency-independent imbalance respectively. The simulation results demonstrate the excellent performance of the method. The average IRR of compensated signal can achieve 54dB, which improves about 30dB compared with uncompensated signal. Besides, the robustness of the proposed method is proved by the simulation as well.