Disclosed is a system and a method of baseband linearization for a class G radiofrequency power amplifier, the linearization system including a module for selecting the amplifier power supply voltage, a digital predistortion module, and a module for extracting predistortion coefficients, wherein the linearization system also includes a digital filter with complex coefficients, the input of which is connected to the output of the digital predistortion module, and a module for extracting filter coefficients which is designed to extract filter coefficients used by the digital filter with complex coefficients.