Apparatus and method for compensating I/Q imbalance based on gain-controlled reference channel in orthogonal frequency division multiplex

A method for compensating a gain imbalance between an I-channel signal and a Q-channel signal, the method comprising the steps of:

• a) controlling a gain of a signal selected from the I-channel signal and the Q-channel signal to have a predetermined amplitude, and to generate a gain-controlled signal, wherein a gain of a selected channel signal is controlled until a sum of absolute value of the selected channel signal and a remaining channel signal is equal to a predetermined gain value by using an auto gain control loop;
• b) detecting a gain imbalance between the gain-controlled signal and the remaining channel signal;
• and
• c) compensating the gain imbalance of the remaining channel signal based on the detected gain imbalance.

A computer readable recording medium for storing instructions for executing a method for compensating a gain imbalance between an I-channel signal and a Q-channel signal, the method comprising the steps of:

• a) controlling a gain of a signal selected from the I-channel signal and the Q-channel signal to have a predetermined amplitude, thereby generating a gain-controlled signal;
• b) detecting a gain imbalance between the gain-controlled signal and a remaining channel signal, wherein the gain imbalance is detected by calculating a difference value between an absolute value of the gain-controlled signal and an absolute value of the remaining channel signal, and multiplying the difference value and a loop gain to generate the gain imbalance;
• and
• c) compensating the gain imbalance of the remaining channel signal based on the detected gain imbalance.