Patent ID: 8619905
Filing Date: 2013-12-31
Classification: H03F,H04L

Abstract:
1. A predistorter comprising: a distortion compensating unit which gives, in advance, a reverse characteristic of a characteristic of input to output of a power amplifier to a transmission signal which is to be input to the power amplifier; a measurement control unit that measures one or more adjacent channel leakage power ratios in an output signal of the power amplifier; a delay unit which generates delayed transmission data by delaying transmission data that is sample data of the transmission signal by a delay time determined according to the one or more adjacent channel leakage power ratios in the output signal of the power amplifier; and a distortion compensation signal generating unit which generates a distortion compensation signal indicating the reverse characteristic based on the transmission data and the delayed transmission data, wherein the delay unit controls the delay amount of the transmission data according to a difference between an adjacent channel leakage power ratio on a low frequency said and the adjacent channel leakage power ratio on a high frequency side in the output signal of the power amplifier.