Method and system for extending dynamic range of an RF signal

• US 7,696,821 B2
• Filed: 09/28/2007
• Issued: 04/13/2010
• Est. Priority Date: 07/31/2007
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Rofougaran, Ahmadreza
• Primary Examiner(s): Nguyen; Khanh V
• Application Number:
  US11/864,857
• Publication Number:
  US 20090033526A1
• Time in Patent Office: 928 Days
• Field of Search: 330/10, 330/136, 330/297, 375/297, 455/127.1, 455/127.2
• US Class Current: 330/136
• CPC Class Codes: H03G 7/001 without controlling loop H03G7/007, H03G7/02, H03G7/06 take precedence

Abstract

Aspects of a method and system for extending dynamic range of an RF signal are provided. In this regard, a signal representative of an amplitude of a pair of baseband signals may be generated. The amplitude of the generated signal may be expanded, and the amplitude of the baseband signals may be compressed. In this regard, the compression and the expansion may be inverse functions of each other. Additionally, the compressed baseband signals may be combined to generate an intermediate signal which may be amplitude modulated by the expanded signal. The amplitude modulation may result from controlling a gain, a voltage source, and/or a current source of a power amplifier. The intermediate signal may be generated by up-converting the baseband signals and subsequently combining the up-converted signals.

Claims

1. A method for communication, the method comprising:

performing, by one or more circuits in a transmitting device;

squaring each signal of a pair of baseband signals and calculating a square root of a sum of said squared signals, to generate a signal that is representative of an amplitude of said pair of baseband signals, wherein said baseband signals correspond to information to be transmitted;

expanding an amplitude of said generated signal;

compressing an amplitude of each signal of said pair of baseband signals;

generating an intermediate signal from said compressed signals;

amplitude modulating said intermediate signal by said expanded signal; and

transmitting said amplitude modulated signal.

2. The method according to claim 1, comprising generating said intermediate signal by up-converting said compressed signals and combining said up-converted signals.

3. The method according to claim 2, comprising up-converting said compressed signals by mixing an in-phase signal of said compressed signals with a first local oscillator signal and mixing a quadrature-phase signal of said compressed signals with a second local oscillator signal, wherein said first local oscillator signal and said second local oscillator signal are in phase-quadrature.

4. The method according to claim 1, comprising amplitude modulating said intermediate signal by controlling a gain of a power amplifier.

5. The method according to claim 1, comprising amplitude modulating said intermediate signal by controlling a current source supplying a power amplifier.

6. The method according to claim 1, comprising amplitude modulating said intermediate signal by controlling a voltage source supplying a power amplifier.

7. The method according to claim 1, wherein said expansion is an inverse function of said compression.

8. A computer-readable storage having stored thereon, a computer program having at least one code section for communication, the at least one code section being executable by a machine for causing the machine to perform steps comprising:

in a transmitting device;

squaring each signal of a pair of baseband signals and calculating a square root of a sum of said squared signals, to generate a signal that is representative of an amplitude of said pair of baseband signals, wherein said baseband signals correspond to information to be transmitted;

expanding an amplitude of said generated signal;

compressing an amplitude of each signal of said pair of baseband signals;

generating an intermediate signal from said compressed signals;

amplitude modulating said intermediate signal by said expanded signal; and

transmitting said amplitude modulated.

9. The computer-readable storage according to claim 8, wherein said at least one code section comprises code for generating said intermediate signal by up-converting said compressed signals and combining said up-converted signals.

10. The computer-readable storage according to claim 9, wherein said at least one code section comprises code for up-converting said compressed signals by mixing an in-phase signal of said compressed signals with a first local oscillator signal and mixing a quadrature-phase signal of said compressed signals with a second local oscillator signal, wherein said first local oscillator signal and said second local oscillator signal are in phase-quadrature.

11. The computer-readable storage according to claim 8, wherein said at least one code section comprises code for amplitude modulating said intermediate signal by controlling a gain of a power amplifier.

12. The computer-readable storage according to claim 8, wherein said at least one code section comprises code for amplitude modulating said intermediate signal by controlling a current source supplying a power amplifier.

13. The computer-readable storage according to claim 8, wherein said at least one code section comprises code for amplitude modulating said intermediate signal by controlling a voltage source supplying a power amplifier.

14. The computer-readable storage according to claim 8, wherein said expansion is an inverse function of said compression.

15. A system for communication, the system comprising:

one or more circuits for use in a transmitter, said one or more circuits operable to;

square each signal of a pair of baseband signals and calculate a square root of a sum of said squared signals, to generate a signal that is representative of an amplitude of said pair of baseband signals, wherein said baseband signals correspond to information to be transmitted;

expand an amplitude of said generated signal;

compress an amplitude of each signal of said pair of baseband signals;

generate an intermediate signal from said compressed signals;

amplitude modulate said intermediate signal by said expanded signal; and

transmit said amplitude modulated.

16. The system according to claim 15, wherein said one or more circuits are operable to generate said intermediate signal by up-converting said compressed signals and combining said up-converted signals.

17. The system according to claim 16, wherein said one or more circuits are operable to up-convert said compressed signals by mixing an in-phase signal of said compressed signals with a first local oscillator signal and mixing a quadrature-phase signal of said compressed signals with a second local oscillator signal, wherein said first local oscillator signal and said second local oscillator signal are in phase-quadrature.

18. The system according to claim 15, wherein said one or more circuits are operable to amplitude modulate said intermediate signal by controlling a gain of a power amplifier.

19. The system according to claim 15, wherein said one or more circuits are operable to amplitude modulate said intermediate signal by controlling a current source supplying a power amplifier.

20. The system according to claim 15, wherein said one or more circuits are operable to amplitude modulate said intermediate signal by controlling a voltage source supplying a power amplifier.

21. The system according to claim 15, wherein said expansion is an inverse function of said compression.