High efficiency linearization power amplifier for wireless communication

Patent metadata

Field	Value
Publication number	US-10305521-B2
Application number	US-201715682431-A
Country	US
Kind code	B2
Filing date	Aug 21, 2017
Priority date	May 1, 2002
Publication date	May 28, 2019
Grant date	May 28, 2019

Abstract

A method and a predistortion system for linearizing an output of a power amplifier include receiving a first input signal representative of an analog RF modulated signal of the predistortion system, receiving a digitized reference signal representative of an idealized reference signal, and receiving a digitized feedback signal representative of nonlinear characteristics of the power amplifier. The method further includes generating, using a lookup table, a predistortion correction signal based on an error between the digitized reference signal and the digitized feedback signal. The first input signal and the predistortion correction signal are combined to produce a predistortion signal that is supplied to the power amplifier to linearize the output of the power amplifier.

First claim

What is claimed is:

1. A predistortion system for linearizing an output of a power amplifier, the predistortion system comprising:
a first input operable to receive a first input signal representative of an analog RF modulated signal;
a second input operable to receive a digitized reference signal representative of an idealized reference signal;
a third input operable to receive a digitized feedback signal representative of nonlinear characteristics of the power amplifier;
a predistortion controller operable to generate, using a lookup table, a predistortion correction signal based on a first error signal between the digitized reference signal and the digitized feedback signal;
combining logic operable to combine the first input signal and the predistortion correction signal to produce a predistortion signal that is supplied to the power amplifier to linearize the output of the power amplifier; and
error logic operable to determine the first error signal as a difference between a square of the digitized reference signal and a square of the digitized feedback signal.

2. The predistortion system of claim 1 , further comprising:
a multiplier operable to multiply the first error signal by an adaptive factor.

3. The predistortion system of claim 1 , wherein the digitized reference signal and the digitized feedback signal each include an in-phase component and a quadrature component, and wherein the predistortion controller is operable to form a first component of the predistortion correction signal using the in-phase components and a second component of the predistortion correction signal using the quadrature components.

4. The predistortion system of claim 3 , wherein the predistortion controller is operable to perform a first lookup in the lookup table for the in-phase component of the digitized reference signal and a second lookup in the lookup table for the quadrature component of the digitized reference signal.

5. The predistortion system of claim 1 , wherein the lookup table receives, as a first lookup table input, an address derived from the digitized reference signal.

6. The predistortion system of claim 5 , wherein the predistortion controller further comprises an address former operable to generate the address based on the digitized reference signal.

7. The predistortion system of claim 5 , wherein the lookup table receives, as a second lookup table input, a second error signal derived from the first error signal and from a previous value output by the lookup table.

8. A method for linearizing an output of a power amplifier, the method comprising:
receiving a first input signal representative of an analog RF modulated signal of a predistortion system;
receiving a digitized reference signal representative of an idealized reference signal;
receiving a digitized feedback signal representative of nonlinear characteristics of the power amplifier;
generating, using a lookup table, a predistortion correction signal based on a first error signal between the digitized reference signal and the digitized feedback signal;
combining the first input signal and the predistortion correction signal to produce a predistortion signal that is supplied to the power amplifier to linearize the output of the power amplifier; and
determining the first error signal as a difference between a square of the digitized reference signal and a square of the digitized feedback signal.

9. The method of claim 8 , further comprising:
multiplying the first error signal by an adaptive factor.

10. The method of claim 8 , further comprising:
receiving, as a first input to the lookup table, an address derived from the digitized reference signal.

11. The method of claim 10 , further comprising:
receiving, as a second input to the lookup table, a second error signal derived from the first error signal and from a previous value output by the lookup table.

12. The method of claim 8 , wherein the digitized reference signal and the digitized feedback signal each include an in-phase component and a quadrature component, the method further comprising:
forming a first component of the predistortion correction signal using the in-phase components; and
forming a second component of the predistortion correction signal using the quadrature components.

13. The method of claim 12 , further comprising:
performing a first lookup in the lookup table for the in-phase component of the digitized reference signal; and
performing a second lookup in the lookup table for the quadrature component of the digitized reference signal.

Assignees

• Dali Wireless Inc

Inventors

• Yang Dali
• Yang Jia

Classifications

• H03F2201/3233

  Adaptive predistortion using lookup table, e.g. memory, RAM, ROM, LUT, to generate the predistortion · CPC title

• H04B2001/0425

  with linearisation using predistortion · CPC title

• H03F3/19

  with semiconductor devices only · CPC title

• H03F3/21

  with semiconductor devices only {(H03F3/245 takes precedence)} · CPC title

• H04B1/0475 Primary

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