METHOD AND APPARATUS FOR DIGITAL PREDISTORTION FOR A SWITCHED MODE POWER AMPLIFIER

• US 20160028433A1
• Filed: 10/06/2015
• Published: 01/28/2016
• Est. Priority Date: 03/10/2014
• Status: Abandoned Application

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Ding, Lei, Hezar, Rahmi
• Application Number:
  US14/876,310
• Publication Number:
  US 20160028433A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H03F 1/3241 using predistortion circuits H03F1/3211, H03F1/3217 take precedence
• CPC Class Codes: H03F 1/3247 using feedback acting on predistortion circuits H03F1/3264 takes precedence
• CPC Class Codes: H03F 3/217 Class D power amplifiers; Switching amplifiers
• CPC Class Codes: H04B 1/0475 with means for limiting noise, interference or distortion H04B1/0483 takes precedence
• CPC Class Codes: H04B 1/62 for providing a predistortion of the signal in the transmitter and corresponding correction in the receiver, e.g. for improving the signal/noise ratio
• CPC Class Codes: H04B 2001/0425 with linearisation using predistortion
• CPC Class Codes: H04L 25/03012 operating in the time domain H04L25/03165, H04L25/03178 take precedence
• CPC Class Codes: H04L 25/03343 Arrangements at the transmitter end
• CPC Class Codes: H04L 25/49 using code conversion at the transmitter; using predistortion; using insertion of idle bits for obtaining a desired frequency spectrum; using three or more amplitude levels ; Baseband coding techniques specific to data transmission systems spectral shaping H04L25/03828

Abstract

A method includes receiving an input signal and predistorting a baseband representation of the input signal at a carrier frequency and at one or more harmonic frequencies. The method also includes generating an output signal based on the predistorted baseband representation of the input signal, and transmitting the output signal to a power amplifier. Predistorting the baseband representation of the input signal at the carrier frequency could occur in parallel with predistorting the baseband representation of the input signal at the one or more harmonic frequencies.

Claims

1. A method comprising:

receiving an input signal;

predistorting a baseband representation of the input signal at a carrier frequency and at one or more harmonic frequencies;

generating an output signal based on the predistorted baseband representation of the input signal; and

transmitting the output signal to a power amplifier.

2. The method of claim 1, wherein predistorting the baseband representation of the input signal at the carrier frequency occurs in parallel with predistorting the baseband representation of the input signal at the one or more harmonic frequencies.

3. The method of claim 1, wherein the output signal comprises a sum of (i) the baseband representation of the input signal predistorted at the carrier frequency and (ii) the baseband representation of the input signal predistorted at the one or more harmonic frequencies.

4. The method of claim 1, wherein the one or more harmonic frequencies comprise a first harmonic frequency and a second harmonic frequency.

5. The method of claim 1, wherein predistorting the baseband representation of the input signal at the carrier frequency comprises using a formula of:

6. The method of claim 1, wherein the power amplifier comprises a switched mode power amplifier.

7. An apparatus comprising:

a digital predistortion block comprising;

a first processing unit configured to receive an input signal and predistort a baseband representation of the input signal at a carrier frequency; and

second processing units configured to receive the input signal and predistort a baseband representation of the input signal at one or more harmonic frequencies;

the digital predistortion block configured to generate an output signal based on the predistorted baseband representation of the input signal and transmit the output signal to a power amplifier.

8. The apparatus of claim 7, wherein the first processing unit and the second processing units are configured to receive the input signal and operate in parallel.

9. The apparatus of claim 7, wherein the digital predistortion block is configured to generate the output signal by summing a predistorted output signal from the first processing unit and predistorted output signals from the second processing units.

10. The apparatus of claim 7, wherein the one or more harmonic frequencies comprise a first harmonic frequency and a second harmonic frequency.

11. The apparatus of claim 7, wherein the first processing unit is configured to predistort the input signal at the carrier frequency using a formula of:

12. The apparatus of claim 7, wherein the digital predistortion block is configured to transmit the output signal to a switched mode power amplifier.

13. A non-transitory computer readable medium encoded with computer-executable instructions that when executed cause at least one processing device to:

receive an input signal;

predistort a baseband representation of the input signal at a carrier frequency and at one or more harmonic frequencies;

generate an output signal based on the predistorted baseband representation of the input signal; and

transmit the output signal to a power amplifier.

14. The non-transitory computer readable medium of claim 13, wherein the predistortion of the baseband representation of the input signal at the carrier frequency comprises using a formula of: