Abstract: In a distortion compensating apparatus for adaptively compensating a non-linear distortion of a circuit having the non-linear distortion, an adaptive equalizing processor adaptively selects, from among a filter coefficient group preliminarily held in a memory, a filter coefficient which makes an out-of-band power of an output signal reduced to be set in a digital filter.

Abstract: In a distortion compensating apparatus for adaptively compensating a non-linear distortion of a circuit having the non-linear distortion, an adaptive equalizing processor adaptively selects, from among a filter coefficient group preliminarily held in a memory, a filter coefficient which makes an out-of-band power of an output signal reduced to be set in a digital filter.

Abstract: The present invention provides a transmission device for predistorting a digital signal in order to compensate distortion, then amplifying and transmitting it. A digital input signal is converted to a first analog signal by a first D/A converter. Separately, the digital input signal is also subjected to predistortion. A compensating signal is then generated from the digital input signal and the predistorted signal. The compensating signal generated thereby is converted into a second analog signal by a second D/A converter. The first analog signal and second analog signal are then added, this addition operation giving a compensated analog transmission signal. This analog transmission signal is supplied to the amplifier for amplification, and then transmitted via an antenna.