Patent attributes
Provided is a distortion compensation apparatus which can correspond to the number of carriers adaptively. The apparatus includes a distortion compensation processing circuit multiplying an input signal by a distortion compensation coefficient; a distortion compensation coefficient storage storing the distortion compensation coefficient correspondingly to the input signal power; a distortion compensation coefficient calculator calculating an update value of the distortion compensation coefficient stored in the distortion compensation coefficient storage, based on the input signal and a feedback signal being feedbacked from the output side of a distortion device; a digital filter inputting the output of the distortion compensation processing circuit. Further is included a modifying unit, which modifies the passband of the digital filter so as to reduce a distortion compensation control bandwidth in the predistortion portion, in response to the reduction of the number of carriers in the input signal.
