Distortion compensation device and distortion compensation method

Patent metadata

Field	Value
Publication number	US-9755675-B2
Application number	US-201615355208-A
Country	US
Kind code	B2
Filing date	Nov 18, 2016
Priority date	Nov 20, 2015
Publication date	Sep 5, 2017
Grant date	Sep 5, 2017

Abstract

A distortion compensation device coupled to an amplifier configured to amplify power of a transmission signal, the distortion compensation device including a memory, and a processor coupled to the memory and the processor configured to obtain the transmission signal sampled with a first sampling rate, obtain the transmission signal sampled with a second sampling rate, the second sampling rate being higher than the first sampling rate, extract an odd-order harmonic from the transmission signal sampled with the second sampling rate, correct a phase and an amplitude of the odd-order harmonic, add the corrected odd-order harmonic to the transmission signal with a first sampling rate, and output, toward the amplifier, the transmission signal to which the corrected odd-order harmonic is added.

First claim

What is claimed is:

1. A distortion compensation device coupled to an amplifier configured to amplify power of a transmission signal, the distortion compensation device comprising:
a memory; and
a processor coupled to the memory and the processor configured to:
obtain the transmission signal sampled with a first sampling rate;
obtain the transmission signal sampled with a second sampling rate, the second sampling rate being higher than the first sampling rate;
extract an odd-order harmonic from the transmission signal sampled with the second sampling rate;
correct a phase and an amplitude of the odd-order harmonic;
add the corrected odd-order harmonic to the transmission signal with the first sampling rate; and
output, toward the amplifier, the transmission signal to which the corrected odd-order harmonic is added.

2. The distortion compensation device according to claim 1 ,
wherein the second sampling rate is a power of the first sampling rate.

3. The distortion compensation device according to claim 1 ,
wherein the first processor is configured to:
calculate an adjacent channel leakage power of the transmission signal after the amplification by the amplifier; and
control an amount of phase shift of a variable phase shifter to be used for correcting the phase and the amplitude of the odd-order harmonic, and a gain of a variable gain controller based on the adjacent channel leakage power.

4. The distortion compensation device according to claim 3 ,
wherein the first processor is configured to:
change the amount of phase shift in sequence;
obtain the adjacent channel leakage power corresponding to the amount of phase shift for each change of the amount of phase shift; and
set the amount of phase shift having the minimum corresponding adjacent channel leakage power in the variable phase shifter out of a predetermined number of the amounts of phase shift.

5. The distortion compensation device according to claim 4 ,
wherein the first processor is configured to:
determine, after the setting the amount of phase shift, whether the adjacent channel leakage power is less than or equal to a standard value while repeatedly increasing or decreasing the gain such that an adjacent channel leakage power becomes less than or equal to a value calculated previous time; and
set the gain corresponding to the adjacent channel leakage power having less than or equal to the standard value in the variable gain controller.

6. A compensating distortion method executed by a computer, the compensating distortion method comprising:
obtaining a transmission signal sampled with a first sampling rate;
obtaining the transmission signal sampled with a second sampling rate, the second sampling rate being higher than the first sampling rate;
extracting an odd-order harmonic from the transmission signal sampled with the second sampling rate;
correcting a phase and an amplitude of the odd-order harmonic;
adding the corrected odd-order harmonic to the transmission signal with the first sampling rate; and
outputting, toward an amplifier coupled to the computer, the transmission signal to which the corrected odd-order harmonic is added.

Assignees

• Fujitsu Ltd

Inventors

• Ohta Kohei

Classifications

• H04B1/0475 Primary

  with means for limiting noise, interference or distortion (H04B1/0483 takes precedence) · CPC title

• H04B2001/0425

  with linearisation using predistortion · CPC title