Patent Document ID: 20110163806
Application ID: 13062039
Patent Flag: 0

Claim One:
1. A distortion compensation amplification device having a pre-distorter that generates and outputs a signal with an inverse characteristic of a non-linear characteristic to an amplifier so as to compensate for distortion resulting from the non-linear characteristic of the amplifier, the distortion compensation amplification device comprising: level detecting means for detecting a level of a signal input to the pre-distorter; correspondence storage means for storing a correspondence between a distortion compensation coefficient for executing pre-distortion and the level of the signal input to the pre-distorter; pre-distortion executing means for giving the inverse characteristic of the non-linear characteristic of the amplifier to the signal input to the pre-distorter in accordance with the distortion compensation coefficient for executing the pre-distortion and outputting the resultant signal to the amplifier; filtering means for removing a frequency component of desired-waves from a feedback signal output from the amplifier and outputting a distortion component; and correspondence acquiring means for updating a pre-distortion learning coefficient constituting a function of giving the inverse characteristic of the non-linear characteristic of the amplifier to the signal input to the pre-distorter so as to reduce the distortion component acquired by the filtering means, acquiring the correspondence between the distortion compensation coefficient for executing the pre-distortion and the level of the signal input to the pre-distorter in accordance with the updated pre-distortion learning coefficient, and outputting the acquired correspondence to the correspondence storage means, wherein the function of giving the inverse characteristic of the non-linear characteristic of the amplifier is expressed using a set of orthogonal polynomials, wherein each orthogonal function of the set of orthogonal polynomials is the total sum of products of one or more functions of the input signal and parameters corresponding to each of the functions of the input signal, and wherein the parameters corresponding to the one or more functions of the input signal are set to cause the orthogonal functions to be orthogonal to each other when functions, which are acquired by applying a filter with the same filter characteristic as that of the filtering means to the functions of the input signal, are replaced for the functions of the input signal of the orthogonal functions.