APPARATUS AND METHODS FOR PROVIDING A POWER AMPLIFIER WITH INTERFERENCE CANCELLATION

• US 20150031317A1
• Filed: 07/24/2013
• Published: 01/29/2015
• Est. Priority Date: 07/24/2013
• Status: Active Grant

• Current Assignee: RPX Corporation
• Original Assignee: Nokia Corporation
• Inventors: Wang, Zhancang
• Granted Patent: US 9,214,968 B2
• Time in Patent Office: Days
• US Class Current: 455/114.3
• CPC Class Codes: H03F 1/3223 using feed-forward H03F1/3211 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 2001/0441 with linearisation using feed-forward

Abstract

Methods and apparatus are provided for amplifying an input signal. An electronic circuit system comprises a first circuit comprising a power amplifier, configured to receive a first branch of an input signal, and generate a first amplified signal based on the input signal of the first branch; a second circuit, configured to receive a second branch of the input signal, generate a cancellation signal based on the input signal of the second branch, and combine the first amplified signal and the cancellation signal to generate a second amplified signal. The second circuit comprises an interference re-construction module, which is configured to model an inverse characteristic of residual distortion and interference of the first circuit via a predefined re-construction function, and generate an anti-phased interference signal based on the input signal of the second branch and the predefined re-construction function. The cancellation signal is generated from the anti-phased interference signal.

Claims

1. An electronic circuit system for amplifying an input signal, comprising:

a first circuit comprising a power amplifier, configured to receive a first branch of an input signal, and generate a first amplified signal based on the input signal of the first branch; and

a second circuit, configured to receive a second branch of the input signal, generate a cancellation signal based on the input signal of the second branch, and combine the first amplified signal and the cancellation signal to generate a second amplified signal,

wherein the second circuit comprises an interference re-construction module, which is configured to model an inverse characteristic of residual distortion and interference of the first circuit via a predefined re-construction function, and generate an anti-phased interference signal based on the input signal of the second branch and the predefined re-construction function, and wherein the cancellation signal is generated from the anti-phased interference signal.

2. An electronic circuit system of claim 1, wherein the interference re-constructor model comprises:

an interference re-constructor, configured to generate an interference re-construction signal based on the input signal of the second branch and the predefined re-construction function, wherein the interference re-construction signal comprises an bypassed input signal and the anti-phased interference signal which has an inverse characteristic of residual distortion and interference of the first circuit;

a delayer, configured to delay the input signal of the second branch to match to a time for generating the interference re-construction signal, and provide a delayed input signal to a subtracter; and

the subtracter, configured to subtract the delayed input signal from the interference re-construction signal to separate the anti-phased interference signal.

3. An electronic circuit system of claim 2, wherein the second circuit comprises a pre-distortion amplifier configured to amplify the separated anti-phased interference signal to output the cancellation signal.

4. An electronic circuit system of claim 2, further comprising:

a third circuit, configured to receive the first amplified signal and attenuate the first amplified signal to generate a feedback signal; and

wherein the interference re-constructor model further comprises an interference re-construction updater, configured to receive the feedback signal, adaptively model a characteristic of residual distortion and interference of the first circuit based on the feedback signal, and provide coefficients of the interference re-construction updater to the interference re-constructor to update coefficients of the re-construction function of the interference re-constructor.

5. An electronic circuit system of claim 4, wherein the first circuit comprises:

a pre-distorter, configured to receive the input signal of the first branch and the feedback signal, and perform a pre-distortion processing on the input signal of the first branch based on the feedback signal, to provide a pre-distorted input signal to the power amplifier.

6. An electronic circuit system of claim 1, wherein the predefined re-construction function is at least one of a look-up table, volterra series, or a memory polynomial function.

13. A transmitter, comprising:

an electronic circuit system according to any one of claims 1-6, for amplifying a radio frequency signal; and

an antenna, configured to transmit the amplified radio frequency signal.

7. A method for amplifying an input signal, comprising:

amplifying the input signal via a power amplifier in a first circuit to generate a first amplified signal in a first circuit; and

generating a cancellation signal based on the input signal in a second circuit; and

combining the first amplified signal and the cancellation signal to generate a second amplified signal,

wherein the generating of the cancellation signal comprises;

modeling an inverse characteristic of residual distortion and interference of the first circuit via a predefined re-construction function;

constructing an anti-phased interference signal based on the input signal and the predefined re-construction function; and

generating the cancellation signal from the anti-phased interference signal.

8. A method of claim 7, wherein constructing an anti-phased interference signal comprises:

generating an interference re-construction signal, which comprises a bypassed input signal, and the anti-phased interference signal having an inverse characteristic of residual distortion and interference of the first circuit;

delaying the input signal to match a time for generating the interference re-construction signal; and

subtracting the delayed input signal from the interference re-construction signal to separate the anti-phased interference signal.

9. A method of claim 8, wherein generating the cancellation signal comprising:

amplifying the separated anti-phased interference signal by a pre-distortion amplifier to output the cancellation signal.

10. A method of claim 8, further comprising:

attenuating the first amplified signal to generate a feedback signal in a third circuit;

adaptively modeling a characteristic of residual distortion and interference of the first circuit based on the feedback signal in an interference re-construction updater; and

updating coefficients of the re-construction function according to model coefficients of the interference re-construction updater.

11. A method of claim 10, further comprising:

performing a pre-distortion processing on the input signal based on the feedback signal, to provide a pre-distorted input signal to the power amplifier.

12. A method of claim 7, wherein the predefined re-construction function is at least one of a look-up table, volterra series, or a memory polynomial function.