PREDISTORTION APPARATUS AND METHOD FOR LINEARIZING THE LOCAL OSCILLATOR COUPLING EFFECT AND THE POWER AMPLIFIER NONLINEARITY

摘要

PURPOSE: A predistortion apparatus and method for linearizing a local oscillator coupling effect and a nonlinearity of a nonlinear power amplifier are provided to improve power amplifier efficiency for a transmitter which is comprised of one chip by providing a predistortion technique. CONSTITUTION: A predistorter(10) linearizes nonlinear characteristics. A modulator(20) modulates an output signal of the predistorter. A power amplifier(30) amplifies a modulated signal. A demodulator(40) feeds back an output of the power amplifier. A coefficient estimator(50) extracts a coefficient from the predistorter using an output signal and a feedback signal of the predistorter. A feedback coefficient estimator(60) estimates a feedback nonlinear distortion coefficient using the output signal and the feedback signal of the predistorter. A feedback equalizer(70) equalizes the feedback signal using results of the feedback coefficient estimator. [Reference numerals] (10) Predistorter; (20) Modulator; (30) Power amplifier; (40) Demodulator; (50) Coefficient estimator; (60) Feedback coefficient estimator; (70) Feed-back equalizer