Patent ID: 7885351

Claim:
A method of correcting a gain and phase imbalance of an analogue modulator for multiple digital channels of a multi-carrier transmission signal, wherein the different channels are to be transmitted on different carrier frequencies, the method comprising the steps of a) determining a gain imbalance correction factor and phase imbalance correction factor for each channel individually and b) applying said correction factors to the corresponding channel individually, before a multi-carrier synthesis of the channels is done, wherein step a) for each one of the multiple channels is performed in a time-multiplexed manner with step a) for the other ones of the multiple channels, whereby said correction factors being applied in a continuous manner, using new correction factors as soon as new correction factors have been determined; and wherein step a) further comprises the steps of: ai) channel-separating a RF signal output by said modulator, aii) comparing the channel-separated modulator output signal with the corresponding input channel signal for each channel individually.