METHOD AND SYSTEM FOR CLOSED LOOP POWER CONTROL IN WIRELESS SYSTEMS

• US 20090264091A1
• Filed: 01/09/2009
• Published: 10/22/2009
• Est. Priority Date: 04/17/2008
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Riondet, Philippe, Serrano, Louie, Raith, Eric, Darabi, Hooman, Jensen, Henrik, Lettieri, Paul
• Granted Patent: US 8,280,324 B2
• Time in Patent Office: Days
• US Class Current: 455/296
• CPC Class Codes: H03G 3/3047 for intermittent signals, e.g. burst signals
• CPC Class Codes: H04B 2001/0416 having gain or transmission power control

Abstract

Aspects of a method and system for closed loop power control in wireless systems are provided. In this regard, an output power of an amplifier may be measured and an indication of the measured power may be compared to a reference signal. The results of the comparison are utilized to generate an error correction factor. The gain of a preamplifier may be adjusted utilizing the error correction factor, where the output of the preamplifier may be input to the amplifier. The error correction factor may be generated via a proportional integral derivative controller. The gain of the preamplifier may be adjusted via at least one control signal, where the at least one control signal may be generated based on a reference control word and the error correction factor. The indication of the measured power and the reference signal may be time aligned.

Claims

1. A method for wireless communications the method comprising:

receiving an indication of a measured output power of an amplifier;

generating an error correction factor by comparing said indication to a reference signal, wherein said indication and said reference signal are time aligned; and

adjusting a gain of a preamplifier based on said error correction factor, wherein said output of said preamplifier is an input of said amplifier.

2. The method according to claim 1, comprising generating said error correction factor via a proportional integral derivative controller

3. The method according to claim 1, comprising adjusting said gain of said preamplifier via at least one gain control signal.

4. The method according to claim 3, wherein said gain control signal is generated based on a reference control word and said error correction factor.

5. The method according to claim 1, comprising delaying one or both of said reference signal and said indication such that they are time aligned.

6. The method according to claim 1, comprising adjusting said gain of said preamplifier via two gain control terminals.

7. The method according to claim 6, comprising amplitude modulating said output of said preamplifier via one of said two gain control terminals.

8. The method according to claim 1, wherein said reference signal ramps up during a first portion of a transmit time slot and ramps down during a second portion of a transmit time slot.

9. The method according to claim 1, comprising generating said error correction factor during a first transmit time slot and adjusting said gain of said preamplifier during a subsequent time slot.

10. The method according to claim 1, comprising scaling a signal that amplitude modulates said output of said of preamplifier to perform said adjusting of said gain of said preamplifier.

11. A system for wireless communications, the system comprising:

one or more circuits operable to, at least;

receive an indication of a measured output power of an amplifier;

generate an error correction factor by comparing said indication to a reference signal, wherein said indication and said reference signal are time aligned; and

adjust a gain of a preamplifier based on said error correction factor, wherein said output of said preamplifier is an input of said amplifier.

12. The system according to claim 11, wherein said one or more circuits are operable to generate said error correction factor via a proportional integral derivative controller

13. The system according to claim 11, wherein said one or more circuits are operable to adjust said gain of said preamplifier via at least one gain control signal.

14. The system according to claim 13, wherein said gain control signal is generated based on a reference control word and said error correction factor.

15. The system according to claim 11, wherein said one or more circuits are operable to delay one or both of said reference signal and said indication such that they are time aligned.

16. The system according to claim 11, wherein said one or more circuits are operable to adjust said gain of said preamplifier via two gain control terminal.

17. The system according to claim 16, wherein said one or more circuits are operable to amplitude modulate said output of said preamplifier via one of said two gain control terminals.

18. The system according to claim 11, wherein said reference signal ramps up during a first portion of a transmit time slot and ramps down during a second portion of a transmit time slot.

19. The system according to claim 11, wherein said one or more circuits are operable to generate said error correction factor during a first transmit time slot and adjust said gain of said preamplifier during a subsequent time slot.

20. The system according to claim 11, wherein said one or more circuits are operable to scale a signal that amplitude modulates said output of said of preamplifier to perform said adjusting of said gain of said preamplifier.