Patent ID: 6993091

Claim:
A method of determining correction parameters used for correcting DC-offset of an I/Q (Inphase/Quadrature phase) modulator in a transmitter, which transmitter comprises an I/Q modulator for I/Q-modulating a signal to be transmitted and a corrector for correcting the DC-offset caused by the I/Q modulator according to the correction parameters, the method comprising the steps of: feeding I/Q-plane test vectors being comprised of I- and Q-test signals into the transmitter; sampling the I/Q-modulated test signals to be transmitted; A/D-converting the signal samples taken from the test signals to be transmitted; I/Q-demodulating the signal samples digitally into I- and Q-feedback signals; determining the DC-offset caused by the I/Q modulator on the basis of the test vectors and the feedback vectors caused by the test vectors and being comprised of the I- and Q-feedback signals; and determining the correction parameters of the DC-offset on the basis of the determined DC-offset.