UNCORRELATED ADAPTIVE PREDISTORTER FOR REDUCING DISTORTION OF RF POWER AMPLIFIER IN MOBILE PHONE SYSTEM

摘要

PURPOSE: An uncorrelated adaptive predistorter for reducing distortion of an RF power amplifier in a mobile phone system is provided to enhance the efficiency by reducing non-linearity in a responding process. CONSTITUTION: An uncorrelated adaptive predistorter includes an input loop and an output loop. The input loop(18) is designed to be coupled to an input of an RF power amplifier. The input loop includes a look-up table containing predistortion values. The input loop is designed to apply the predistortion values to an input signal in response to a monotonically increasing function of the input signal power in order to form a predistorted input signal. The output loop(16) is coupled to the output of the RF power amplifier. The output loop is designed to measure an intermodulation distortion product of the RF power amplifier output resulting from the predistorted input signal. The output loop is operable to update the predistortion values in the look-up table.