IP Library Granted Patent US 9,705,541
Granted Patent B2
US 9,705,541 · App. 15/140,599 · Granted Jul 11, 2017

Method and system for crest factor reduction

Inventors: Ramesh Sridhar (Carlsbad, CA); Timothy Gallagher (Carlsbad, CA); Shantha Murthy Prem Swaroop (Carlsbad, CA); Ali Shahed Hagh Gadam (Carlsbad, CA)
Assignee: Maxlinear, Inc.
H04B1/0475H03F1/3241H03F1/3247H03F3/195H03F3/213H03F3/24H03G3/3042H03F2200/451H03F2201/3215H04B2001/045H04B2001/0425
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Quick Facts
Patent No.
US 9,705,541
App. No.
15/140,599
Granted
Jul 11, 2017
Kind
B2
Abstract

Methods and systems for crest factor reduction may comprise generating an original waveform to be amplified by a programmable gain amplifier (PGA); generating a distortion signal utilizing a PGA model that predicts an output signal of the PGA based on the original waveform; generating an error signal by subtracting out the original waveform from the distortion signal; filtering the generated error signal; generating a conditioned waveform with crest factor reduced from that of the original waveform by adding the filtered error signal to the original waveform; and amplifying the conditioned waveform. The crest factor of the original waveform may be reduced based on spectral mask requirements. The generating of the conditioned waveform may be iterated. The distortion signal may be generated based on a predistortion model. A signal may be fed back from an output of the PGA to the predistortion model, which may be dynamically configured.

Claims (39)

1. A method for communication, the method comprising:

communicating an input signal to a programmable gain amplifier (PGA);

generating a distortion signal utilizing a PGA model that predicts an output signal of the PGA based on the input signal;

generating an error signal by subtracting out the input signal from the distortion signal;

filtering the generated error signal;

generating a conditioned waveform with crest factor reduced from that of the input signal by adding the filtered error signal to the input signal; and

amplifying the conditioned waveform.

2. The method according to claim 1 , comprising reducing the crest factor of the input signal based on spectral mask requirements.

3. The method according to claim 1 , comprising iterating the generating of the conditioned waveform.

4. The method according to claim 1 , comprising generating the distortion signal based on a predistortion model.

5. The method according to claim 4 , comprising feeding back a signal from an output of the PGA to the predistortion model.

6. The method according to claim 4 , comprising dynamically configuring the predistortion model.

7. The method according to claim 1 , comprising reducing the crest factor of the input signal in an analog domain.

8. The method according to claim 1 , comprising reducing the crest factor of the input signal in a digital domain.

9. The method according to claim 1 , comprising filtering the error signal utilizing a distortion shaping filter.

10. A system for communication, the system comprising:

one or more circuits on a chip comprising a transmitter, said one or more circuits being operable to:

communicate an input signal to a programmable gain amplifier (PGA) for subsequent transmission;

generate a distortion signal utilizing a PGA model that predicts an output signal of the PGA based on the input signal;

generate an error signal by subtracting the input signal from the distortion signal;

filter the generated error signal;

generate a conditioned waveform with crest factor reduced from that of the input signal by adding the filtered error signal to the input signal; and

amplify the conditioned waveform.

11. The system according to claim 10 , wherein said one or more circuits are operable to reduce the crest factor of said input signal based on spectral mask requirements.

12. The system according to claim 10 , wherein said one or more circuits are operable to iterate the generating of the conditioned waveform.

13. The system according to claim 10 , wherein said one or more circuits are operable to generate the distortion signal based on a predistortion model.

14. The system according to claim 13 , wherein said one or more circuits are operable to feed back a signal from an output of the PGA to the predistortion model.

15. The system according to claim 13 , wherein said one or more circuits are operable to dynamically configure the predistortion model.

16. The system according to claim 10 , wherein said one or more circuits are operable to reduce the crest factor of the input signal in an analog domain.

17. The system according to claim 10 , wherein said one or more circuits are operable to filter the error signal utilizing a distortion shaping filter.

18. A method for communication, the method comprising:

generating an input signal to be amplified by a programmable gain amplifier (PGA);

generating a distortion signal utilizing a PGA model that predicts an output signal of the PGA based on the input signal;

generating an error signal by subtracting out the input signal from the distortion signal;

filtering the error signal utilizing a distortion shaping filter;

generating a conditioned waveform with crest factor reduced from that of the input signal by adding the filtered error signal to the input signal; and

amplifying the conditioned waveform.

19. The method according to claim 18 , comprising reducing the crest factor of the input signal based on spectral mask requirements.

20. The method according to claim 18 , comprising iterating the generating of the conditioned waveform.

Assignments (4)
SECURITY AGREEMENT Recorded Jul 9, 2021
From: MAXLINEAR, INC.; MAXLINEAR COMMUNICATIONS, LLC; EXAR CORPORATION
To: WELLS FARGO BANK, NATIONAL ASSOCIATION
Reel/Frame 056816/0089 →
RELEASE OF SECURITY INTEREST Recorded Jun 23, 2021
From: MUFG UNION BANK, N.A.
To: MAXLINEAR, INC.; EXAR CORPORATION; MAXLINEAR COMMUNICATIONS LLC
Reel/Frame 056656/0204 →
SUCCESSION OF AGENCY (REEL 042453 / FRAME 0001) Recorded Jul 1, 2020
From: JPMORGAN CHASE BANK, N.A.
To: MUFG UNION BANK, N.A.
Reel/Frame 053115/0842 →
SECURITY AGREEMENT Recorded May 12, 2017
From: MAXLINEAR, INC.; ENTROPIC COMMUNICATIONS, LLC (F/K/A ENTROPIC COMMUNICATIONS, INC.); EXAR CORPORATION
To: JPMORGAN CHASE BANK, N.A., AS COLLATERAL AGENT
Reel/Frame 042453/0001 →
Continuity (3)
Continuation 14589801 · Jan 5, 2015
Provisional Application 61923338 · Jan 3, 2014
Related Publication 20160248458A1 · Aug 25, 2016