Patent ID: 9319002
Filing Date: 2016-04-19
CPC Classification: H03F,H04B,H04L

Claim Text:
1. A distortion compensation circuit which compensates distortion of a high-frequency power amplifier which power-amplifies an OFDM input signal having a frequency converted in a high-frequency band or an OFDM input signal in a high-frequency band, comprising: an odd symmetrical distortion compensation signal generation circuit to independently generate an odd symmetrical distortion compensation coefficient signal of each order of the high-frequency power amplifier from a high-frequency signal or a high-frequency IF signal or a high-frequency OFDM input signal which is an input signal in a high-frequency band (hereinafter referred to as a high-frequency OFDM input signal) obtained by subjecting an OFDM signal to orthogonal modulation and digital-up conversion; an odd symmetrical distortion compensation signal addition circuit to prepare an error odd symmetrical distortion compensation signal from error of the high-frequency OFDM input signal, an output of the high-frequency power amplifier and an odd symmetrical distortion compensation coring signal obtained by coring the generated odd symmetrical distortion compensation coefficient signal of each order and add an odd symmetrical distortion compensation signal obtained by adding the error odd symmetrical distortion compensation signal and the odd symmetrical distortion compensation coefficient signal to the high-frequency OFDM input signal; an even symmetrical distortion compensation signal generation circuit to independently generate an even symmetrical distortion compensation coefficient signal of each order of the high-frequency power amplifier from the high-frequency OFDM input signal; and an even symmetrical distortion compensation signal addition circuit to prepare an error even symmetrical distortion compensation signal from error of the high-frequency OFDM input signal, the output of the high-frequency power amplifier and an even symmetrical distortion compensation coring signal obtained by coring the generated even symmetrical distortion compensation coefficient signal of each order and add an even symmetrical distortion compensation signal obtained by adding the error even symmetrical distortion compensation signal and the even symmetrical distortion compensation coefficient signal to the high-frequency OFDM input signal, wherein odd symmetrical distortion and even symmetrical distortion are configured to be compensated independently.