Technique for output power dithering for improved transmitter performance

• US 7,869,408 B2
• Filed: 02/18/2004
• Issued: 01/11/2011
• Est. Priority Date: 02/18/2004
• Status: Active Grant

• Current Assignee: Intellectual Ventures I LLC (Intellectual Ventures LLC)
• Original Assignee: Xocyst Transfer AG LLC (Intellectual Ventures LLC)
• Inventors: Seals, Michael J., Harriman, Adam K.
• Primary Examiner(s): Taylor; Barry W
• Application Number:
  US10/779,606
• Publication Number:
  US 20050180359A1
• Time in Patent Office: 2,519 Days
• Field of Search: 370/333, 370/318, 455/522
• US Class Current: 370/333
• CPC Class Codes: H04W 52/20 using error rate
• CPC Class Codes: H04W 52/286 during data packet transmission, e.g. high speed packet access [HSPA]

Abstract

A technique for admission control of packet flows is disclosed. In one particular exemplary embodiment, the technique may be realized as a method for output power dithering for improved transmitter performance. The method may comprise transmitting a plurality of packets at a first output power, determining a first error rate associated with the transmission of the plurality of packets at the first output power, transmitting the plurality of packets at at least one second output power different from the first output power, determining at least one second error rate associated with the transmission at the at least one second output power, and identifying a desired output power based at least in part on a comparison between the first error rate and the at least one second error rate.

Claims

1. A method for adjusting output power for a transmitter, the method comprising:

determining whether a first error rate associated with a transmission of a plurality of packets at a first output power exceeds a threshold error rate;

responsive to the first error rate exceeding the threshold error rate, transmitting the plurality of packets at a second output power, wherein the second output power is less than the first output power;

determining whether a second error rate associated with the transmission of the plurality of packets at the second output power is less than the first error rate; and

responsive to the second error rate being less than the first error rate, dithering the output power for the transmitter below the first output power until a target error rate is achieved.

2. The method of claim 1, further comprising initially determining the first error rate by measuring a number of failed acknowledgments of transmitted packets.

3. The method of claim 1 further comprising, responsive to the second error rate being greater than the first error rate:

transmitting the plurality of packets at a third output power, wherein the third output power is greater than the second output power;

determining a third error rate associated with the transmission at the third output power;

if the third error rate is less than the first error rate, then dithering the output power for the transmitter above the first output power until a target error rate is achieved; and

if the third error rate is greater than the first error rate, then restoring the first output power as the output power for the transmitter.

4. The method of claim 3:

wherein dithering the output power for the transmitter below the first output power until a target error rate is achieved comprises adjusting the output power up and down in steps until the target error rate is achieved, wherein, at each step, the output power for the transmitter is less than the first output power; and

wherein dithering the output power for the transmitter above the first output power until a target error rate is achieved comprises adjusting the output power up and down in steps until the target error rate is achieved, wherein, at each step, the output power for the transmitter is greater than the first output power.

5. A method for adjusting output power for a transmitter, the method comprising:

transmitting a plurality of packets at a first output power;

determining a first error rate associated with the transmission of the plurality of packets at the first output power;

comparing the first error rate to a predetermined error rate value; and

responsive to the first error rate being greater than the predetermined error rate value, transmitting the plurality of packets at a second output power, wherein the second output power is less than the first output power;

determining a second error rate associated with the transmission at the second output power;

transmitting the plurality of packets at a third output power, wherein the third output power is greater than the second output power;

determining a third error rate associated with the transmission at the third output power; and

based at least in part on a comparison between the first error rate the second error rate, and the third error rate, setting the output power for the transmitter.

6. The method of claim 5, wherein setting the output power for the transmitter comprises, if the second error rate is less than the first error rate and the third error rate, adjusting the second output power until a desired error rate is reached.

7. The method of claim 5, wherein setting the output power for the transmitter comprises, if the third error rate is less than the first error rate and the second error rate, adjusting the third output power until a desired error rate is reached.

8. The method of claim 5, wherein determining the first error rate comprises measuring a number of failed acknowledgments of transmitted packets.

9. The method of claim 5, wherein the transmission at the first output power is associated with a variable data rate.

10. The method of claim 9, wherein the first error rate, the second error rate, the third error rate, and the predetermined error rate value are associated with the variable data rate.

11. The method of claim 5, wherein the transmission at the first output power, the second output power, and the third output power is associated with a variable data rate.

12. The method of claim 11, wherein the first error rate, the second error rate, the third error rate, and the predetermined error rate value are associated with the variable data rate.

13. A system for adjusting output power for a transmitter, the system comprising:

a transmitter configured to transmit a plurality of packets at a first output power; and

a processor configured to;

determine a first error rate associated with the transmission of the plurality of packets at the first output power;

determine whether the first error rate is greater than a predetermined error rate;

responsive to the first error rate being greater than the predetermined error rate, cause the transmitter to transmit the plurality of packets at a second output power, wherein the second output power is less than the first output power;

determine a second error rate associated with the transmission at the second output power;

cause the transmitter to transmit the plurality of packets at a third output power, wherein the third output power is greater than the output power;

determine a third error rate associated with the transmission at the third output power; and

identify a desired output power based at least in part on a comparison between the first error rate, the second error rate, and the third error rate.

14. A system for adjusting output power for a transmitter, the system comprising:

means for transmitting a plurality of packets at a first output power;

means for determining a first error rate associated with the transmission of the plurality of packets at the first output power;

means for, in response to the first error rate being greater than a predetermined error rate, transmitting the plurality of packets at a second output power, wherein the second output power is less than the first output power;

means for determining a second error rate associated with the transmission at the second output power;

means for transmitting the plurality of packets at a third output power, wherein the third output power is greater than the first output power;

means for determining a third error rate associated with the transmission at the third output power; and

means for identifying a desired output power based at least in part on a comparison between the first error rate, the second error rate, and the third error rate.

15. The system of claim 14, further comprising:

means for identifying, the second output power as a desired output power if the second error rate is lower than at least the third error rate; and

means for identifying the third output power as the desired output power if the third error rate is lower than at least the second error rate.

16. The system of claim 14, wherein the plurality of packets is transmitted in accordance with an IEEE 802.11 protocol.

17. A tangible computer readable storage medium encoded with instructions capable of being executed by a computer to adjust output power for a transmitter adjusting for improved transmitter performance, wherein the instruction, when executed, cause the computer to perform operations comprising:

transmitting a plurality of packets at a first output power;

determining a first error rate associated with the transmission of the plurality of packets at the first output power;

in response to the first error rate being greater than a predetermined error rate, transmitting the plurality of packets at a second output power, wherein the second output power is less than the first output power;

determining a second error rate associated with the transmission at the second output power,

transmitting the plurality of packets at a third output power, wherein the third output power is greater than the first output power;

determining a third error rate associated with the transmission at the third output power; and

identifying a desired output power based at least in part on a comparison between the first error rate, the second error rate, and the third error rate.

18. A method for adjusting output power for a transmitter, the method comprising:

determining whether a first error rate associated with a transmission of a plurality of packets at a first output power exceeds a threshold error rate;

responsive to the first error rate exceeding the threshold error rate, transmitting the plurality of packets at a second output power, wherein the second output power is less than the first output power;

determining a second error rate associated with the transmission at the second output power;

based at least in part on a comparison of the first error rate and the second error rate, determining that transmission distortion is a cause of the first error rate exceeding the threshold error rate; and

responsively setting the output power for the transmitter below the first output power.