Distortion compensating apparatus and method

A distortion compensating apparatus which compensates for nonlinearity of an amplifier by adaptively updating a distortion compensation coefficient for an input signal input to the amplifier based on a difference between an input signal and an output signal of the amplifier, said apparatus comprising:

• distortion amount detecting means which detects the amount of distortion of an output signal of the amplifier;
• parameter holding means which holds a parameter having been set therein, said parameter holding means being capable of varying the difference according to the parameter set therein;
• parameter correcting means which corrects the parameter held in said parameter holding means, regarding the distortion amount detected by said distortion amount detecting means as a reference, in such a manner that the distortion amount is improved;
• and
• distortion amount correcting means which corrects the distortion amount detected by said distortion amount detecting means in such a manner that the distortion amount regarded as the reference is reduced by an offset amount according to a detection error.