Abstract: Method of correcting a gain and phase imbalance of an analogue modulator (32) for multiple channels (CHi) of a multi-carrier transmission signal, the method comprising the steps of determining a gain imbalance correction factor (GCFi) and phase imbalance correction factor (PCFi) for each channel individually and applying said correction factors (GCFi, PCFi) to the corresponding channel (CHi) individually, before the multi-carrier synthesis of the channels is done, whereas step a) for each one of the multiple channels (CHi) is performed in a time-multiplexed manner with step a) for the other ones of the multiple channels (CHi).

Abstract: Frequency differences between differing clock sources are compensated for by an adaptive filtering mechanism. An amount of frequency drift between two clock sources is determined. Then, based on that amount of frequency drift, a filtering value is selected to be used in tracking the frequency drift. If the frequency drift is determined to be large, then a minimum filtering value is selected. However, if it is determined to be small, then a maximum filtering value is selected. The selected filtering value is used to adjust the address(es) of one or more data bits being transmitted and received using the two clock sources, such that the frequency drift is properly tracked.