Predistortion processing apparatus and method

Patent metadata

Field	Value
Publication number	US-10075324-B2
Application number	US-201715599956-A
Country	US
Kind code	B2
Filing date	May 19, 2017
Priority date	Nov 19, 2014
Publication date	Sep 11, 2018
Grant date	Sep 11, 2018

Abstract

A predistortion processing apparatus: an auxiliary feedback module, configured to: extract a nonlinear distortion signal from an analog signal, and input an obtained feedback signal corresponding to the nonlinear distortion signal into an auxiliary model coefficient training module; the auxiliary model coefficient training module, configured to: train an auxiliary coefficient according to the feedback signal and a predistortion signal, and transmit a first auxiliary coefficient obtained through training to a predistortion processing module; a radio frequency signal feedback module, configured to extract a fundamental wave feedback signal; a predistortion model coefficient training module, configured to: train a predistortion coefficient according to the predistortion signal and the fundamental wave feedback signal, and transmit an obtained predistortion coefficient to the predistortion processing module; the predistortion processing module, configured to: perform predistortion processing on an input intermediate frequency signal by performing nonlinear modeling according to the first auxiliary coefficient and the predistortion coefficient.

First claim

What is claimed is:

1. A predistortion processing apparatus comprising:
an auxiliary feedback circuit, configured to:
receive an amplified analog signal,
extract a nonlinear distortion signal from the amplified analog signal,
obtain a feedback signal corresponding to the nonlinear distortion signal, and
input the feedback signal into an auxiliary model coefficient training circuit;

the auxiliary model coefficient training circuit being configured to:
receive the feedback signal and a predistortion signal that is output by a predistortion processing circuit,
train an auxiliary coefficient of the auxiliary model coefficient training circuit according to the feedback signal and the predistortion signal that is output by the predistortion processing circuit, and
transmit a first auxiliary coefficient obtained through training to the predistortion processing circuit;

a radio frequency signal feedback circuit configured to:
receive the amplified analog signal, extract a fundamental wave signal from the amplified analog signal,
obtain a fundamental wave feedback signal corresponding to the fundamental wave signal, and
input the fundamental wave feedback signal into a predistortion model coefficient training circuit;

the predistortion model coefficient training circuit configured to:
receive the fundamental wave feedback signal and the predistortion signal that is output by the predistortion processing circuit,
train a predistortion coefficient of the predistortion model coefficient training circuit according to the fundamental wave feedback signal and the predistortion signal that is output by the predistortion processing circuit, and
transmit a predistortion coefficient obtained through training to the predistortion processing circuit; and

the predistortion processing circuit configured to perform predistortion processing on an input intermediate frequency signal by performing nonlinear modeling according to the first auxiliary coefficient and the predistortion coefficient, and output a predistortion signal obtained through predistortion processing.

2. The apparatus according to claim 1 , wherein the nonlinear distortion signal comprises an envelope signal, and the auxiliary feedback circuit is configured to: receive the amplified analog signal, extract the envelope signal from the amplified analog signal, perform sampling processing on the envelope signal, obtain an envelope feedback signal corresponding to the envelope signal, and input the envelope feedback signal into the auxiliary model coefficient training circuit.

3. The apparatus according to claim 2 , wherein the predistortion processing circuit comprises a first auxiliary filtering subcircuit and a first predistortion processing subcircuit, and the predistortion model coefficient training circuit comprises a second auxiliary filtering subcircuit and a first predistortion coefficient processing subcircuit; and
the auxiliary model coefficient training circuit is configured to:
train the auxiliary coefficient of the auxiliary model coefficient training circuit by performing modeling by using the predistortion signal and the envelope feedback signal that are input into the auxiliary model coefficient training circuit,
obtain a second auxiliary coefficient after the training, and
transmit the second auxiliary coefficient to the first auxiliary filtering subcircuit and the second auxiliary filtering subcircuit.

4. The apparatus according to claim 3 , wherein the first auxiliary filtering subcircuit is configured to:
construct, according to the intermediate frequency signal input into the predistortion processing circuit, an envelope reference signal corresponding to the intermediate frequency signal,
perform filtering processing on the envelope reference signal by using the second auxiliary coefficient, and
input an obtained first output signal into the first predistortion processing subcircuit;
the first predistortion processing subcircuit is configured to:
generate a predistortion vector according to a preset predistortion model by using the first output signal output by the first auxiliary filtering subcircuit and a clipping-processed baseband signal that is input into the first predistortion processing subcircuit,
multiply the predistortion vector by the predistortion coefficient to obtain the predistortion signal, and
output the predistortion signal;
the second auxiliary filtering subcircuit is configured to:
perform, by using the second auxiliary coefficient,
filtering processing on the fundamental wave feedback signal output by the radio frequency signal feedback circuit, and
input an obtained second output signal into the first predistortion coefficient processing subcircuit; and
the first predistortion coefficient processing subcircuit is configured to:
perform nonlinear modeling according to the second output signal, the fundamental wave feedback signal input into the first predistortion coefficient processing subcircuit, and the predistortion signal,
train the predistortion coefficient of the predistortion model coefficient training circuit, and
obtain the predistortion coefficient.

5. The apparatus according to claim 1 , wherein the nonlinear distortion signal comprises an envelope signal and a harmonic signal, and the auxiliary feedback circuit is configured to:
receive the amplified analog signal, extract the envelope signal and the harmonic signal from the amplified analog signal,
perform sampling processing on the envelope signal and the harmonic signal,
obtain an envelope feedback signal corresponding to the envelope signal and a harmonic feedback signal corresponding to the harmonic signal, and
input the envelope feedback signal and the harmonic feedback signal into the auxiliary model coefficient training circuit.

6. The apparatus according to claim 5 , wherein the predistortion processing circuit comprises a third auxiliary filtering subcircuit and a second predistortion processing subcircuit, and the predistortion model coefficient training circuit comprises a fourth auxiliary filtering subcircuit and a second predistortion coefficient processing subcircuit; and
the auxiliary model coefficient training circuit is configured to:
train the auxiliary coefficient of the auxiliary model coefficient training circuit by performing modeling by using the predistortion signal, the envelope feedback signal, and the harmonic feedback signal that are input into the auxiliary model coefficient training circuit,
obtain a third auxiliary coefficient after training, and transmit the third auxiliary coefficient to the third auxiliary filtering subcircuit and the fourth auxiliary filtering subcircuit.

7. The apparatus according to claim 6 , wherein the third auxiliary filtering subcircuit is configured to:
construct, according to the intermediate frequency signal input into the predistortion processing circuit, an envelope reference signal and a harmonic reference signal that correspond to the intermediate frequency signal,
perform filtering processing on the envelope reference signal and the harmonic reference signal by using the third auxiliary coefficient, and
input an obtained third output signal into the second predistortion processing subcircuit;
the second predistortion processing subcircuit is configured to:
generate a predistortion vector according to a preset predistortion model by using the third output signal output by the third auxiliary filtering subcircuit and a clipping-processed baseband signal that is input into the predistortion processing subcircuit,
multiply the predistortion vector by the predistortion coefficient to obtain the predistortion signal, and output the predistortion signal;

the fourth auxiliary filtering subcircuit i

Assignees

• Huawei Tech Co Ltd

Inventors

• Zhao Yanqing
• Yu Chunlei
• Tian Tingjian

Classifications

• H04L27/368 Primary

  adaptive predistortion · CPC title

• H03F1/3258 Primary

  based on polynomial terms · CPC title

• H03F1/3294

  Acting on the real and imaginary components of the input signal · CPC title

• H03F2200/102

  A non-specified detector of a signal envelope being used in an amplifying circuit · CPC title

• H03F3/189

  High-frequency amplifiers, e.g. radio frequency amplifiers · CPC title