METHOD AND APPARATUS FOR OPTIMIZING TRANSMITTER POWER EFFICIENCY

• US 20120087441A1
• Filed: 12/14/2011
• Published: 04/12/2012
• Est. Priority Date: 12/02/2002
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: CHAN, Wen-Yen, JIN, Xin, JIAO, Qing Zhong
• Granted Patent: US 8,599,963 B2
• Time in Patent Office: Days
• US Class Current: 375/297
• CPC Class Codes: H03G 3/3042 in modulators, frequency-changers, transmitters or power amplifiers transmission power control in bidirectional transmission systems H04W52/04
• CPC Class Codes: H04L 27/2614 Peak power aspects
• CPC Class Codes: H04W 52/52 using AGC [Automatic Gain Control] circuits or amplifiers

Abstract

A peak to average power ratio signal is generated from a first mapping function that selects the peak to average power ratio signal that corresponds to the data rate or data format of the signal to be transmitted. The selected peak to average power ratio signal is summed with a desired average transmit power signal. The resulting summation signal is input to a second effectively continuously valued mapping function comprising a table that has a plurality of power amplifier control signal values each with a corresponding peak transmit power. Each peak transmit power signal value results in a power amplifier control signal value that achieves the best possible transmitter power efficiency while still meeting out of band spurious emissions and waveform quality requirements. The summation signal value maps to one of the power amplifier control signal value that is then used to adjust a parameter such as bias of the power amplifier.

Claims

1. A transmitter apparatus comprising:

a mapping function configured to select an output value for a power amplifier control signal in response to a received desired average transmit power level value, the mapping function comprising an array of output values for the power amplifier control signals, each output value of the output values associated with a value for possible desired average transmit power values; and

a power amplifier coupled to a radio frequency signal and the power amplifier control signal, at least one parameter within the power amplifier being adjusted in response to the power amplifier control signal.

2. The apparatus of claim 1, wherein the mapping function is effectively continuously valued.

3. The apparatus of claim 1 wherein the power amplifier control signal is an analog signal.

4. The apparatus of claim 1 wherein the power amplifier control signal is a digital signal.

5. The apparatus of claim 1 wherein the mapping function selects the output values within the function such that each corresponding transmit power value results in an optimized transmitter power efficiency value while still meeting out of band spurious emissions and waveform quality requirement.

6. The apparatus of claim 1 wherein the at least one parameter within the power amplifier is at least one of a bias, a power supply voltage, a stage switch-in feature, a stage switch-out feature, a turning on feature, a turning off feature, a gain, a gain distribution, a conducting angle, an amplifier class change feature, a load, or an impedance.

7. The apparatus of claim 1 wherein the desired average transmit power level value is converted to an analog signal prior to being input to the mapping function.

8. The apparatus of claim 1, wherein the radio frequency signal is generated by a data encoder and modulator from an input signal.

9. The apparatus of claim 8, further comprising a digital to analog converter coupled to the data encoder and modulator.

10. The apparatus of claim 9, further comprising an automatic gain control amplifier coupled to the digital to analog converter.

11. The apparatus of claim 10, wherein the automatic gain control amplifier generates an automatic gain control amplifier control signal in response to the desired average transmit power level value.

12. The apparatus of claim 1, further comprising a generator to generate the desired average transmit power level value, the desired average transmit power level value being derived from at least one of an open loop power control signal and a closed loop power control signal.

18. The method of claim 1, further comprising, prior to the selecting, generating the desired average transmit power level value, the desired average transmit power level value being derived from at least one of an open loop power control signal and a closed loop power control signal.

13. A method within a transmitter apparatus comprising:

selecting an output value for a power amplifier control signal in response to a received desired average transmit power level value at a mapping function within the transmitter apparatus, the selecting utilizing an array of output values for the power amplifier control signals, each output value of the output values associated with a value for possible desired average transmit power values; and

adjusting at least one parameter within a power amplifier of the transmitter apparatus, for amplifying a radio frequency signal in response to the power amplifier control signal.

14. The method of claim 13, wherein the mapping function is effectively continuously valued.

15. The method of claim 13 wherein the power amplifier control signal is one of an analog signal and a digital signal.

16. The method of claim 13 wherein the at least one parameter within the power amplifier is at least one of a bias, a power supply voltage, a stage switch-in feature, a stage switch-out feature, a turning on feature, a turning off feature, a gain, a gain distribution, a conducting angle, an amplifier class change feature, a load, or an impedance.

17. The method of claim 13 wherein the desired average transmit power level value is converted to an analog signal prior to being input to the mapping function.