A multicarrier transmitter is shown having an embodiment of the invention. Sampling of modulated and amplified signals is done to obtain energy values for four or more symbols. Combining the energy values with the baseband in-phase and quadrature signals of the multiple carriers may result in a set of imbalance parameters, which are subsequently stored. Later baseband in phase and quadrature signals are predistorted or compensated by applying the stored imbalance parameters to produce new compensated baseband in-phase and compensated baseband quadrature signals, which are suitable for input to an inverse fast fourrier transform (IFFT) block.