Patent ID: 8358719

Claim:
Method for simultaneous compensation of several signal errors occurring in an IQ modulator having an output and two inputs with correction signals respectively inverse to said signal errors, the method comprising: iteratively determining an optimized signal value of each of a plurality of correction signals by measuring a difference between a signal error in an in-phase modulation signal and a quadrature modulation signal and a correction signal of the plurality of correction signals, wherein iteratively determining an optimized signal value comprises determining every difference between the signal error and the correction signal using a complex baseband model on the in-phase modulation signal and on the quadrature-phase modulation signal simultaneously, the complex baseband model being of a transmission behavior between an output and two inputs of the IQ modulator and of a correction circuit connected upstream of the IQ modulator; and subsequently minimizing the difference between the signal error and the correction signal, wherein the complex baseband model is a non-linear equation system with an order corresponding to a number of unknowns contained in the equation system and contains a number, corresponding to the number of unknowns contained in the equation system, of signal values, impressed respectively at the two inputs, for the in-phase modulation signal, the quadrature-phase modulation signal, and an intermediate frequency or high-frequency bandpass signal UDET measured at the output of the IQ modulator, and wherein the equation system is solved with a Newton numerical optimization method or a Brodyn numerical optimization method.