Digital Predistortion Processing Method and Device

• US 20150103952A1
• Filed: 06/19/2012
• Published: 04/16/2015
• Est. Priority Date: 02/28/2012
• Status: Abandoned Application

• Current Assignee: ZTE Corporation
• Original Assignee: ZTE Corporation
• Inventors: Wang, Lin, Wang, Peng, Lei, Hong
• Application Number:
  US14/381,286
• Publication Number:
  US 20150103952A1
• Time in Patent Office: Days
• US Class Current: 375/297
• CPC Class Codes: H03F 1/02 Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation
• CPC Class Codes: H03F 1/3247 using feedback acting on predistortion circuits H03F1/3264 takes precedence
• CPC Class Codes: H03F 3/24 of transmitter output stages
• CPC Class Codes: H04B 1/0475 with means for limiting noise, interference or distortion H04B1/0483 takes precedence
• CPC Class Codes: H04B 17/13 of power amplifiers, e.g. gain or non-linearity
• CPC Class Codes: H04B 2001/045 with means for improving efficiency
• CPC Class Codes: H04L 25/02 Details ; arrangements for supplying electrical power along data transmission lines systems for transmitting signals via power distribution lines H04B3/54
• CPC Class Codes: H04L 27/368 adaptive predistortion

Abstract

A digital predistortion processing method and device, the method comprises: performing digital predistortion processing on a baseband signal according to a first predistortion correction parameter, converting the baseband signal after digital predistortion processing into a radio-frequency signal, dividing the radio-frequency signal, and respectively outputting each path of radio-frequency signal to a distinct power amplifier; and, coupling and outputting the radio-frequency signal output by each power amplifier to a feedback link for combination to obtain a combined signal, and performing conversion processing on the combined signal; and generating a predistortion correction parameter according to the combined signal after conversion processing and the baseband signal before digital predistortion processing, and updating the first predistortion correction parameter to a second predistortion correction parameter.

Claims

1. A digital predistortion processing method, comprising:

performing digital predistortion processing on a baseband signal according to a first predistortion correction parameter, converting the baseband signal after the digital predistortion processing into a radio-frequency signal, dividing the radio-frequency signal, and respectively outputting each path of radio-frequency signal to a distinct power amplifier;

coupling and outputting the radio-frequency signal output by each power amplifier to a feedback link for combination to obtain a combined signal, and performing conversion processing on the combined signal; and

generating a second predistortion correction parameter according to the combined signal after the conversion processing and the baseband signal before the digital predistortion processing, and updating the first predistortion correction parameter as the second predistortion correction parameter.

2. The method according to claim 1, wherein, the step of generating a second predistortion correction parameter according to the combined signal after the conversion processing and the baseband signal before the digital predistortion processing comprises:

processing the combined signal and the baseband signal before the digital predistortion processing to eliminate differences between the combined signal and the baseband signal in delay, amplitude phase, energy and frequency offset, and obtaining an aligned combined signal and the baseband signal before the digital predistortion processing;

performing comparison calculation on the aligned combined signal and the baseband signal before the digital predistortion processing to obtain the second predistortion correction parameter.

3. The method according to claim 1, wherein, the step of performing conversion processing on the combined signal comprises:

down-converting the combined signal into a medium frequency signal, and filtering the medium frequency signal, and converting a filtered combined signal into a digital signal, obtaining the combined signal after the conversion processing.

4. The method according to claim 1, wherein, the step of dividing the radio-frequency signal comprises:

dividing the radio frequency signal into N paths of same radio frequency signal using a power divider, wherein N is an integer greater than 1.

5. The method according to claim 1, wherein, the step of converting the baseband signal into a radio frequency signal comprises:

performing digital-to-analogue conversion on the baseband signal after the digital predistortion processing to obtain an analog signal, and modulating the analog signal into a radio frequency signal through orthogonal modulation.

6. A digital predistortion processing device, comprising:

a digital predistortion processor, a baseband signal conversion circuit, a power divider, a power amplifier, a combiner, a combined signal processing circuit and a digital predistortion training device, wherein;

the digital predistortion processor is configured to perform digital predistortion processing on a baseband signal according to a first predistortion correction parameter, and transmit the baseband signal after the digital predistortion processing to the baseband signal conversion circuit;

the baseband signal conversion circuit is configured to convert the baseband signal after the digital predistortion processing into a radio frequency signal, and transmit the radio frequency signal to the power divider;

the power divider is configured to divide the radio frequency signal, and respectively transmit each path of radio frequency signal to a distinct power amplifier;

the combiner is configured to couple and output the radio frequency signal output by each power amplifier to a feedback link for combination to obtain a combined signal, and transmit the combined signal to the combined signal processing circuit;

the combined signal processing circuit is configured to perform conversion processing on the combined signal, and transmit the combined signal after the conversion processing to the digital predistortion training device;

the digital predistortion training device is configured to generate a second predistortion correction parameter according to the combined signal after the conversion processing and the baseband signal before the digital predistortion processing, and update the second predistortion correction parameter to the digital predistortion processor.

7. The device according to claim 6, wherein, the digital predistortion training device comprises:

a data collecting module, a data processing module, a predistortion correction parameter extraction module and a parameter update module, wherein;

the data collecting module is configured to collect the combined signal and the baseband signal before the digital predistortion processing;

the data processing module is configured to process the combined signal and the baseband signal before the digital predistortion processing to eliminate differences between the combined signal and the baseband signal in delay, amplitude phase, energy and frequency offset, and obtaining an aligned combined signal and the baseband signal before the digital predistortion processing;

the predistortion correction parameter extraction module is configured to perform comparison calculation on the aligned combined signal and the baseband signal before the digital predistortion processing to generate the second predistortion correction parameter;

the parameter updating module is configured to update the second predistortion correction parameter to the digital predistortion processor.

8. The device according to claim 6, wherein, the combined signal processing circuit comprises:

a mixer, a filter and an analog-digital converter, wherein;

the mixer is configured to down-convert the combined signal into a medium frequency signal, and transmit the medium frequency signal to the filter;

the filter is configured to filter the medium frequency signal, and transmit a filtered combined signal to the analog-digital converter;

the analog-digital converter is configured to convert filtered combined signal into a digital signal, obtaining the combined signal after the conversion processing.

9. The device according to claim 6, wherein, the power divider is configured to divide the radio frequency signal into N paths of same radio frequency signal, wherein N is an integer greater than 1.

10. The device according to claim 6, wherein, the baseband signal conversion circuit comprises:

a digital-to-analogue converter and a modulator, wherein;

the digital-to-analogue converter is configured to perform digital-to-analogue conversion on the baseband signal after the digital predistortion processing to obtain an analog signal, and transmit the analog signal to the modulator;

the modulator is configured to modulate the analog signal into a radio frequency signal through orthogonal modulation.