A Method to Alleviate the I/Q Imbalance in Transmitters with More Accurate Loop Gain Estimation

In the zero-IF structure, I/Q imbalance is a problem waiting to be solved. I/Q imbalance could cause generation of mirror signal, leading to interference with the adjacent channel. Generally, we use pre-compensation to eliminate the mirror signal. There is an important part where we need to estimate the loop gain accurately so that the pre-compensation could eliminate the mirror signal. We proposed a new way to estimate the loop gain with Least Square, replacing the traditional way. Better performance of elimination of mirror signal could be got.