Method for the compensation of transmitter I/Q imbalance based on the pre-distortion of baseband signals

摘要

In-phase and quadrature-phase (I/Q) imbalance commonly exists in the transmission channels in orthogonal modulation, especially in a transmitter that adopts the direct frequency conversion structure. This paper proposes a method to correct the transmission channel I/Q imbalance. According to the statistical features of an orthogonal signal, the degree of amplitude and phase imbalance is estimated, and the correction coefficient is calculated by estimating the baseband signal distortion in the digital domain. The method proposed in this paper avoids the requirement for compensation of the receiver and for external devices and has a low algorithm complexity. The effectiveness of the method is verified by simulation.