Patent ID: 7613251
Filing Date: 2009-11-03
Classification: H03F

Abstract:
1. A distortion compensating apparatus which compensates for nonlinearity of an amplifier by quadrature-modulating an input signal before inputting the input signal to the amplifier and by adaptively updating a distortion compensation coefficient for the input signal based on a difference between the 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 in such a manner that the distortion amount detected by said distortion amount detecting means is improved; noise component detecting means which detects a noise component that can be caused in the output signal resulting from the quadrature-modulation; and noise component removing means which performs processing for removing the noise component detected by said noise component detecting means.