An IQ mismatch correction function generator configured to generate an enhanced IQ mismatch correction function to improve the compensation for IQ mismatch, and an IQ signal receiver with the IQ mismatch correction function generator, wherein the enhanced IQ mismatch correction function is determined based on an initial IQ mismatch correction function derived from IQ mismatch estimates corresponding to frequency bins where signals are present and error of the initial IQ mismatch correction function by comparing the values of the initial IQ mismatch correction function with IQ mismatch estimates corresponding to a respective bin of the frequency bins.