Patent ID: 6091941
Filing Date: 2000-07-18
Classification: H01Q,H03C,H03F,H04B,H04L

Abstract:
A radio apparatus for subjecting a modulating signal to pre-distortion processing using distortion compensation coefficients which correct distortion of a transmission power amplifier, amplifying, by the transmission power amplifier, a carrier wave obtained by being digitally modulated by the modulating signal that has been subjected to the pre-distortion processing, transmitting the amplified carrier wave, comparing the modulating signal with a demodulated signal, which is obtained by branching and demodulating the transmitted carrier, and updating the distortion compensation coefficients, said apparatus comprising:phase-difference measuring means for measuring, prior to pre-distortion processing, a phase difference between a demodulated signal and a modulating signal, wherein the demodulated signal is obtained by detecting a carrier wave that is the result of digital modulation by the modulating signal having a fixed phase and amplitude; andphase-difference correcting means for executing phase-difference correction processing in such a manner that the phase difference becomes zero.