Method and apparatus for improving digital predistortion correction with amplifier device biasing

• US 8,374,282 B2
• Filed: 07/24/2008
• Issued: 02/12/2013
• Est. Priority Date: 07/24/2008
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola Mobility LLC (Lenovo Group Ltd.)
• Inventors: Szopko, Robert S., Anderson, Mark B., Niemiec, Scott A.
• Primary Examiner(s): LAM, KENNETH T
• Application Number:
  US12/179,035
• Publication Number:
  US 20100020899A1
• Time in Patent Office: 1,664 Days
• Field of Search: 375/296, 375/297, 375/289, 375/295
• US Class Current: 375/297
• CPC Class Codes: H03F 1/30 Modifications of amplifiers to reduce influence of variations of temperature or supply voltage or other physical parameters in differential amplifiers H03F3/45479
• CPC Class Codes: H03F 1/3241 using predistortion circuits H03F1/3211, H03F1/3217 take precedence
• CPC Class Codes: H03F 2200/447 the amplifier being protected to temperature influence
• CPC Class Codes: H03F 2200/451 the amplifier being a radio frequency amplifier
• CPC Class Codes: H03F 2200/465 Power sensing
• CPC Class Codes: H03F 2201/3233 Adaptive predistortion using lookup table, e.g. memory, RAM, ROM, LUT, to generate the predistortion
• CPC Class Codes: H03F 3/195 in integrated circuits
• CPC Class Codes: H03F 3/24 of transmitter output stages
• CPC Class Codes: H04L 27/367 using predistortion

Abstract

A method, apparatus, and electronic device for using digital predistortion are disclosed. A transmitter 212 may transmits a transmission signal. A receiver 214 may monitor the transmission signal to execute digital predistortion of the transmission signal to compensate for distortion. A field programmable gate array or application specific integrated circuit 226 may adjust a power amplifier bias to improve the digital predistortion.

Claims

1. A method for using digital predistortion in a transmitting circuit, comprising:

monitoring, by a receiver, a transmission signal for distortion;

generating, by the receiver, a distortion observation of the transmission signal in response to monitoring the transmission signal;

receiving, by a digital predistortion block, an input signal and the distortion observation;

executing, by the digital predistortion block, digital predistortion of the transmission signal to account for distortion, wherein the executing comprises comparing the input signal with the distortion observation by calculating a change in phase distortion of the transmission signal relative to the input signal; and

adjusting a power amplifier bias in response to calculating the change in phase distortion of the transmission signal relative to the input signal to improve the digital predistortion.

2. The method of claim 1, further comprising:

adjusting the power amplifier bias by adjusting the gate voltage.

3. The method of claim 1, further comprising:

adjusting the power amplifier bias based on temperature.

4. The method of claim 1, further comprising:

adjusting the power amplifier bias based on drive level.

5. The method of claim 1, further comprising:

using at least one of a field programmable gate array or an application specific integrated circuit.

6. A telecommunications apparatus for using digital predistortion, comprising:

a transmitter that transmits a transmission signal;

a receiver that monitors the transmission signal, wherein the receiver generates a distortion observation of the transmission signal in response to monitoring the transmission signal;

a digital predistortion block that receives the digital predistortion observation and the transmission signal and executes digitally predistortion of the transmission signal to compensate for distortion, wherein the executing comprises comparing the input signal with the distortion observation by calculating a change in phase distortion of the transmission signal relative to the input signal; and

a field programmable gate array that adjusts a power amplifier bias in response to calculating the change in phase distortion of the transmission signal relative to the input signal to improve the digital predistortion.

7. The telecommunications apparatus of claim 6, wherein the field programmable gate array adjusts the power amplifier bias by adjusting the gate voltage.

8. The telecommunications apparatus of claim 6, wherein the field programmable gate array adjusts the power amplifier bias based on temperature.

9. The telecommunications apparatus of claim 6, wherein the field programmable gate array adjusts the power amplifier bias based on drive level.

10. The telecommunications apparatus of claim 6, wherein the field programmable gate array adjusts the power amplifier bias via a digital controlled potentiometer.

11. An electronic device for using digital predistortion, comprising:

a transmitter that transmits a transmission signal;

a receiver that monitors the transmission signal, wherein the receiver generates a distortion observation of the transmission signal in response to monitoring the transmission signal;

a digital predistortion block that receives the digital predistortion observation and the transmission signal and executes digitally predistortion of the transmission signal to compensate for distortion, wherein the executing comprises comparing the input signal with the distortion observation by calculating a change in phase distortion of the transmission signal relative to the input signal; and

an application specific integrated circuit that adjusts a power amplifier bias in response to calculating the change in phase distortion to improve the digital predistortion.

12. The electronic device of claim 11, wherein the application specific integrated circuit adjusts the power amplifier bias by adjusting the gate voltage.

13. The electronic device of claim 11, wherein the application specific integrated circuit adjusts the power amplifier bias based on duty cycle.

14. The electronic device of claim 11, wherein the application specific integrated circuit adjusts the power amplifier bias based on temperature.

15. The electronic device of claim 11, wherein the application specific integrated circuit adjusts the power amplifier bias based on drive level.