An apparatus for processing base band signals and method thereof to provide low level signals for amplification that will improve performance of a multi-channel transmitter. The apparatus includes a first Transform Matrix (TM) coupled to one or more input signals; a processing unit coupled to the output signals for modifying according to a predetermined algorithm each of the output signals to provide modified output signals; a second TM coupled to the modified output signals for decomposing the modified signals, each of the output base band signals corresponding to one of the input signals; and a compensation function arranged and inter-coupled to either the modified output signals or the output base band signals. The transmitter further converts the output base band signals to radio frequency signals. A sampler couples either the amplifier input signal or output signal back to the compensation function as a feedback signal.