METHOD AND APPARATUS FOR IMPROVING POWER AMPLIFIER EFFICIENCY IN WIRELESS COMMUNICATION SYSTEMS HAVING HIGH PEAK TO AVERAGE POWER RATIOS

• US 20090245419A1
• Filed: 06/05/2009
• Published: 10/01/2009
• Est. Priority Date: 02/20/2004
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Chan, Wen-Yen, Jiao, Qingzhong, Khan, Nasserullah, Jin, Xin, Sangary, Nagula Tharma, Habicher, Michael Franz
• Granted Patent: US 7,787,566 B2
• Time in Patent Office: Days
• US Class Current: 375/297
• CPC Class Codes: H04W 52/343 taking into account loading or congestion level

Abstract

A power management system and method for a wireless communication device generates an average desired transmit power signal based on at least one of a received signal strength indicator signal and a power control instruction signal from a base station. A power supply level adjustment signal is generated based on the data parameters of an outgoing data stream and at least one environmental information signal. A combination of the power supply level adjustment signal and the average desired transmit power or a gain control signal and an altered version of the power supply level adjustment signal is used to generate a variable power supply signal that is provided to an output amplifier block for sufficiently generating outgoing wireless device radio signals while reducing power loss in the output amplifier block.

Claims

1. A power management system for powering an output power amplifier block in a wireless communication device, the power management system comprising:

an average power and gain control block configured to provide a gain control signal and an average desired transmit power signal, the average desired transmit power signal being based on at least one of a power control instruction signal and a received signal strength indicator signal;

an environmental sensor configured to provide at least one environmental information signal; and

,

a power supply level adjustment generator implemented by a plurality of look-up tables, and configured to provide a power supply level adjustment signal based on a data parameter indication of a baseband outgoing data stream to be transmitted by the wireless communication device and the at least one environmental information signal, wherein one look-up table is provided for each of the at least one environmental information signal and the data parameter indication, and outputs of each look-up table are combined to generate the power supply level adjustment signal; and

,

a power supply module connected to the average power and gain control block and the power supply level adjustment generator, and configured to provide a variable power supply signal to the output power amplifier block based on the average desired transmit power signal and the power supply level adjustment signal.

2. The power management system of claim 1, wherein the at least one environmental information signal comprises at least one of:

a temperature information signal related to a hardware temperature in the wireless communications device;

a battery condition information signal related to a battery used to power the wireless communication device;

or

a frequency information signal related to a transmission frequency of the baseband outgoing data stream.

3. The power management system of claim 1, wherein the average power and gain control block comprises an average power level block configured to generate the average desired transmit power signal, and a gain control block connected to the average power level block configured to generate the gain control signal.

4. The power management system of claim 1, wherein the power supply module comprises a power supply control block configured to provide a power control signal, and a switch converter connected to the power supply control block configured to receive the power control signal and generate the variable power supply signal.

5. The power management system of claim 1, wherein the power supply module is configured to maintain the variable power supply signal above a minimum voltage level.

6. The power management system of claim 1, wherein at least one of the look-up tables is implemented by a corresponding formula.

7. The power management system of claim 1, wherein the system further comprises a data parameter detector connected to the power supply level adjustment generator and a baseband device of the wireless communications device, wherein the data parameter detector provides the data parameter indication.

8. The power management system of claim 4, wherein the power supply module is calibrated by:

(i) transmitting wireless device radio signals at a constant power level from the wireless communication device while monitoring an Adjacent Channel Power Ratio (ACPR);

(ii) reducing a magnitude of the variable power supply signal while maintaining constant output power in the wireless device radio signals;

(iii) recording the magnitude of the variable power supply signal when the ACPR has increased to a pre-specified design target;

(iv) increasing the output power of the wireless device radio signals and repeating (i) to (iii) for several output power levels; and

,

(v) computing an ideal transfer function for deriving the power control signal for controlling the switch converter.

9. The power management system of claim 8, wherein the power supply control block is further calibrated by:

(vi) repeating (i) to (v) for several different wireless communication devices to obtain an average transfer function; and

,

(vii) performing curve fitting on the average transfer function.

10. The power management system of claim 4, wherein the power supply level adjustment generator is calibrated by:

(i) loading the power supply level adjustment generator with a value at which the output power amplifier block operates at a lowest transmission power point;

(ii) adjusting a transmission power level until an output power of the output power amplifier block slightly exceeds a target power determined for a power supply voltage level;

(iii) interpolating an output value of the average power level and gain control block and loading the interpolated output value, after adjustment by a reverse mapper, into the power supply level adjustment generator;

(iv) adjusting the transmission power level to a value slightly below the target power; and

,

(v) increasing the value of the transmission power level and repeating (i) to (iv) until a maximum specified transmission power point is reached.

11. A method of providing power to an output power amplifier block in a wireless communications device, the method comprising:

receiving a base station radio signal and providing at least one of a received signal strength indicator signal by measuring a signal strength of the base station radio signal, and a power control instruction signal by extracting one or more power control bits from the base station radio signal;

generating an average desired transmit power signal based on at least one of the received signal strength indicator signal and the power control instruction signal;

generating at least one environmental information signal related to the wireless communications device;

generating a power supply level adjustment signal based on a data parameter indication of a baseband outgoing data stream to be transmitted by the wireless device and the at least one environmental information signal, by using the data parameter indication and the at least one environmental information signal as indices into corresponding look-up tables, and combining outputs of the corresponding look-up tables to generate the power supply level adjustment signal; and

,

generating a variable power supply signal based on the average desired transmit power signal and the power supply level adjustment signal, and providing the variable power supply signal to the output power amplifier block.

12. The method of claim 11, wherein generating the at least one environmental signal comprises at least one of:

generating a temperature information signal related to a hardware temperature of the wireless communications device;

generating a battery condition information signal related to a battery used to power the wireless communications device;

or

generating a frequency information signal related to a transmission frequency of the baseband outgoing data stream.

13. The method of claim 11, wherein generating the variable power supply signal comprises:

generating a power control signal based on the average desired transmit power signal and the power supply level adjustment signal; and

,

converting the power control signal into the variable power supply signal.

14. The method of claim 11, wherein the method further comprises maintaining the variable power supply signal above a minimum voltage level.

15. The method of claim 11, further comprising detecting the data parameter indication based on at least one of a data type, data modulation and data rate in the baseband outgoing data stream.

16. The method of claim 11, wherein generating the average desired transmit power signal comprises initializing the average desired transmit power signal to the received signal strength indicator signal, and then refining the average desired transmit power signal based on the power control instruction signal.