Power control techniques for wireless transmitters

• US 20070230616A1
• Filed: 03/31/2006
• Published: 10/04/2007
• Est. Priority Date: 03/31/2006
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Darabi, Hooman, Zolfaghari, Alireza, Jensen, Henrik
• Granted Patent: US 8,467,473 B2
• Time in Patent Office: Days
• US Class Current: 375/297
• CPC Class Codes: H03F 3/24 of transmitter output stages
• CPC Class Codes: H04B 1/406 with more than one transmission mode, e.g. analog and digital modes
• CPC Class Codes: H04B 2001/0408 with power amplifiers
• CPC Class Codes: H04L 27/0008 arrangements for allowing a transmitter or receiver to use more than one type of modulation negotiating modulation type for two-way transmission paths H04L5/1453

Abstract

Various embodiments are disclosed relating to power control techniques for wireless transmitters. In an example embodiment, an apparatus is provided that may include a digital-to-analog converter (DAC) adapted to convert a digital amplitude signal to an analog amplitude signal during a first transmission mode and adapted to convert a digital power level signal to an analog power level signal during a second transmission mode.

Claims

1. An apparatus comprising:

a digital-to-analog converter (DAC) adapted to convert a digital amplitude signal to an analog amplitude signal during a first transmission mode and adapted to convert a digital power level signal to an analog power level signal during a second transmission mode.

2. The apparatus of claim 1 and further comprising:

a circuit, operating in the first transmission mode, receiving a phase modulated signal as a first input, receiving the output from the DAC as a second input, and receiving as a third input an additional power level signal, the circuit adapted to adjust or control the transmission power level during transmission power ramp and during data transmission based on the additional power level signal, the circuit also adapted to output a phase and amplitude modulated signal during data transmission.

3. The apparatus of claim 1 wherein the DAC comprises a DAC adapted to convert a digital amplitude signal to an analog amplitude signal during a first transmission mode and adapted to convert a digital power level signal to an analog power level signal during a second transmission mode, the first transmission mode comprising a transmission mode that employs at least amplitude modulation, the second transmission mode comprising a transmission mode that employs at least phase modulation or frequency modulation.

4. The apparatus of claim 1 wherein the DAC comprises a DAC adapted to convert a digital amplitude signal to an analog amplitude signal during a first transmission mode and adapted to convert a digital power level signal to an analog power level signal during a second transmission mode, the first transmission mode comprising EDGE transmission mode, the second transmission mode comprising GSM/EGSM transmission mode.

5. The apparatus of claim 1 and further comprising a multiplexer having an output coupled to an input of the DAC, the multiplexer adapted to receive multiple input signals and to select for output to the DAC either the digital amplitude signal or the digital power level signal.

6. The apparatus of claim 1 and further comprising a driver circuit adapted to receive a phase modulated signal as a first input, and adapted to receive the analog amplitude signal as a second input during the first transmission mode, the driver circuit adapted to output a phase and amplitude modulated signal during the first transmission mode and to output a phase modulated signal during the second transmission mode.

7. The apparatus of claim 1 and further comprising a switch coupled to an output of the DAC to couple the analog amplitude signal output of the DAC to a sampling circuit during a first transmission mode, and to couple the analog power level signal to a driver circuit during a second transmission mode.

8. The apparatus of claim 1 and further comprising a sampling circuit coupled to an output of the DAC, the sampling circuit adapted to pass the analog power level signal from the DAC during a transmission power ramp during the second transmission mode, and to output a sampled value of the analog power level signal from the sampling circuit during data transmission during the second transmission mode.

9. The apparatus of claim 1 and further comprising:

a voltage controlled oscillator (VCO) to output a phase modulated signal;

a driver circuit adapted to receive the phase modulated signal from the VCO as a first input, the driver circuit also adapted to receive the analog amplitude signal as a second input and a first transmission mode power level signal as a third input during the first transmission mode, the driver circuit adapted to output a phase and amplitude modulated signal during the first transmission mode and to output a phase modulated signal during the second transmission mode.

10. The apparatus of claim 9 and further comprising a power amplifier having an input coupled to an output of the driver circuit.

11. A method comprising:

receiving multiple signals;

providing a multi-mode digital-to-analog conversion, including;

converting a digital amplitude signal to an analog amplitude signal during a first transmission mode; and

converting a digital power level signal to an analog power level signal during a second transmission mode.

12. The method of claim 11 wherein the providing a multi-mode digital-to-analog conversion comprises:

converting a digital amplitude signal to an analog amplitude signal during a first transmission mode that employs at least amplitude modulation;

converting a digital power level signal to an analog power level signal during a second transmission mode that employs at least phase modulation or frequency modulation.

13. The method of claim 11 wherein the receiving multiple signals comprises:

receiving the digital amplitude signal during the first transmission mode;

receiving the digital power level signal during the second transmission mode; and

selecting either the digital amplitude signal or the digital power level signal for digital-to-analog conversion, based on the transmission mode.

14. The method of claim 11 and further comprising:

using the analog power level signal for transmission power control during a transmission power ramp for the second transmission mode; and

using a sampled value of the analog power level signal for transmission power control during at least a portion of the time when the transmission power is not ramping for the second transmission mode.

15. The method of claim 11 and further comprising:

performing the following during the first transmission mode;

receiving the analog amplitude signal;

receiving a phase modulated signal;

receiving an additional power level signal; and

generating a power-adjusted phase and amplitude modulated signal based on the received amplitude signal, the phase modulated signal and the additional power level signal.

16. The method of claim 11 and further comprising:

performing the following during the second transmission mode;

receiving a phase modulated signal;

receiving the analog power level signal;

generating a power-adjusted phase modulated signal based on the received signals.

17. An apparatus comprising:

a digital-to-analog converter (DAC) adapted to convert a digital power level signal to an analog power level signal during a transmission power ramp, and adapted to convert a digital amplitude signal to an analog amplitude signal during data transmission.

18. The apparatus of claim 17 and further comprising:

a circuit receiving a phase modulated signal as a first input and receiving the output from the DAC as a second input, the circuit adapted to adjust the transmission power level during transmission power ramp based on the analog power level signal from the DAC, and adapted to receive the analog amplitude signal from the DAC and output a phase and amplitude modulated signal during data transmission.

19. The apparatus of claim 18 and further comprising a voltage controlled oscillator (VCO) coupled to the circuit, the VCO adapted to generate the phase modulated signal for transmission.

20. The apparatus of claim 18 wherein the circuit also receives as a third input an additional power level signal to be used to control the transmission power level during data transmission.