Predistortion system and method

Patent metadata

Field	Value
Publication number	US-9973219-B2
Application number	US-201715423207-A
Country	US
Kind code	B2
Filing date	Feb 2, 2017
Priority date	Oct 7, 2016
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

A predistortion system for optimizing the performance of a distorting component. The predistortion system comprises a signal generator, the distorting component, an analyzing device for frequency and/or time domain analysis, and a predistortion device. The signal generator generates a first signal according to a reference signal. Furthermore, the first signal after being passed through the distorting component results in a second signal. Then, the second signal after being passed through the analyzing device results in a third signal. Moreover, the third signal after being passed through the predistortion device results in a compensated signal. In addition to this, the reference signal is provided for the predistortion device.

First claim

What is claimed:

1. A predistortion system for optimizing the performance of a distorting component, the predistortion system comprising:
a signal generator,
the distorting component,
an analyzing device for frequency and/or time domain analysis, and
a predistortion device,
wherein the signal generator generates a first signal according to a reference signal,
wherein the first signal after being passed through the distorting component results in a second signal,
wherein the second signal after being passed through the analyzing device results in a third signal,
wherein the third signal after being passed through the predistortion device results in a compensated signal,
wherein the reference signal is provided for the predistortion device,
wherein the compensated signal, which correlates with the reference signal in an iterative manner, is fed back to the signal generator, and
wherein at each iteration step, the predistortion device modifies the compensated signal in a manner that each sample of the compensated signal is replaced by the product of the respective sample of the previous compensated signal, and the quotient of the corresponding sample of the reference signal and the respective sample of the third signal.

2. The predistortion system according to claim 1 ,
wherein the analyzing device is a spectrum analyzer or an oscilloscope or a combination of a down converter and a digitizer.

3. The predistortion system according to claim 1 ,
wherein the distorting component is an amplifier.

4. The predistortion system according to claim 1 ,
wherein at least one of the reference signal, the first signal, the second signal, the third signal, and the compensated signal is a quadrature signal.

5. The predistortion system according to claim 1 ,
wherein at each iteration step, the compensated signal is modified on the basis of the deviation of the third signal from the reference signal.

6. The predistortion system according to claim 1 ,
wherein for initializing the iteration, the compensated signal is set to the reference signal, and
wherein for terminating the iteration, a maximum number of iterations is predefined.

7. A predistortion method for optimizing the performance of a distorting component with the aid of a predistortion system comprising a signal generator, the distorting component, an analyzing device for frequency and/or time domain analysis, and a predistortion device, the method comprising the steps of:
generating a first signal according to a reference signal with the aid of the signal generator, wherein the first signal after being passed through the distorting component results in a second signal, wherein the second signal after being passed through the analyzing device results in a third signal, wherein the third signal after being passed through the predistortion device results in a compensated signal, and
providing the reference signal for the predistortion device,
wherein the compensated signal, which correlates with the reference signal in an iterative manner, is fed back to the signal generator, and
wherein at each iteration step, the predistortion device modifies the compensated signal in a manner that each sample of the compensated signal is replaced by the product of the respective sample of the previous compensated signal, and the quotient of the corresponding sample of the reference signal and the respective sample of the third signal.

8. The predistortion method according to claim 7 ,
wherein the analyzing device is a spectrum analyzer or an oscilloscope or a combination of a down converter and digitizer and/or the distorting component is an amplifier.

9. The predistortion method according to claim 7 ,
wherein at least one of the reference signal, the first signal, the second signal, the third signal, and the compensated signal is a quadrature signal.

10. The predistortion method according to claim 7 ,
wherein at each iteration step, the compensated signal is modified on the basis of the deviation of the third signal from the reference signal.

11. The predistortion method according to claim 7 ,
wherein for initializing the iteration, the compensated signal is set to the reference signal, and
wherein for terminating the iteration, a maximum number of iterations is predefined.

Assignees

• Rohde & Schwarz

Inventors

• Lagler Andreas
• Bunsen Bastian
• Weiss Martin

Classifications

• H03F1/3247 Primary

  using feedback acting on predistortion circuits (H03F1/3264 takes precedence) · CPC title

• H03F3/19

  with semiconductor devices only · CPC title

• H04B2001/0425

  with linearisation using predistortion · CPC title

• H04B1/04 Primary

  Circuits · CPC title

• H03F2201/3215

  To increase the output power or efficiency · CPC title