Estimating and filtering multiple sets of MIPS from different frequencies

A method for compensating a modulation imbalance effect in a communication device, the method comprising:

• receiving first digital samples representing a baseband signal configured to have a first frequency;
• estimating at least three sets of modulation imbalance parameters from the first digital samples, each set of modulation imbalance parameters having a gain modulation imbalance parameter and a phase modulation imbalance parameter;
• generating a first offset signal to cause the baseband signal to be configured to have a second frequency;
• receiving second digital samples representing the baseband signal configured to have the second frequency;
• estimating at least three sets of modulation imbalance parameters from the second digital samples, each set of modulation imbalance parameters having a gain modulation imbalance parameter and a phase modulation imbalance parameter;
• generating a second offset signal to cause the baseband signal to be configured to have a third frequency;
• receiving third digital samples representing the baseband signal configured to have the third frequency;
• estimating at least three sets of modulation imbalance parameters from the third digital samples, each set of modulation imbalance parameters having a gain modulation imbalance parameter and a phase modulation imbalance parameter;
• filtering the gain modulation imbalance parameters and the phase imbalance parameters at each frequency to obtain a filtered set of modulation imbalance parameters for that frequency, each filtered set of modulation imbalance parameters having a gain modulation imbalance parameter and a phase modulation imbalance parameter;
• and
• reconstructing input signals with the filtered set of modulation imbalance parameters for each frequency.