A novel method for estimation and compensation of transmitter I/Q imbalance

In this paper, we study the I/Q imbalance effect of wireless communication systems at the transmitter side and the novel transmitter I/Q imbalance parameters estimation and signal pre-compensation schemes are proposed. The I/Q imbalance parameters estimation of the transmitter is based on the statistical properties of the in-phase and quadrature-phase parts of the signals. The pre-compensation scheme feedbacks the estimated imbalance parameters to the pre-compensation block and the pre-compensation block apply the offsets to the In-phase and quadrature-phase parts of the original low intermediate frequency (LIF) signal before they pass through the up-convertor of the transmitter and the outcome modulated radio frequency (RF) signal will be recovered. Both the signals for the estimation and pre-compensation are low intermediate frequency signals so the estimation and pre-compensation schemes can be realized in the digital domain. Computer simulations are conducted to evaluate the performance of the proposed schemes. It is shown that the proposed schemes are reliable and feasible for practical implementation.