Method and apparatus for multi-channel reverse link outer-loop power control

• US 7,010,316 B2
• Filed: 09/28/2001
• Issued: 03/07/2006
• Est. Priority Date: 09/28/2001
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Chen, Tao
• Primary Examiner(s): Gesesse, Tilahun
• Application Number:
  US09/967,653
• Publication Number:
  US 20030064743A1
• Time in Patent Office: 1,621 Days
• Field of Search: 455/522, 455/69, 455/67.11, 455/67.13, 455/226.1, 455/68, 455/127.1, 370/259, 370/335, 370/331, 370/318, 375/219, 375/222, 375/227
• US Class Current: 455/522
• CPC Class Codes: H04W 52/12 Outer and inner loops
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/16 Deriving transmission power values from another channel
• CPC Class Codes: H04W 52/20 using error rate
• CPC Class Codes: H04W 52/325 Power control of control or pilot channels
• CPC Class Codes: H04W 52/36 with a discrete range or set of values, e.g. step size, ramping or offsets

Abstract

In a disclosed embodiment, a maintain and adjust threshold module determines the desired signal to noise and interference ratio for a first channel. Next, a delta computation module produces a threshold delta, which is then added to a base threshold by way of an adder. The resulting sum is the outer-loop set point that is used in a comparator. The comparator compares a receive signal strength with the outer-loop threshold. The comparator output is inputted to a generate up/down command module. The generate up/down command module sends a down command to the mobile unit if receive signal strength is greater than the outer-loop threshold, otherwise it sends an up command.

Claims

1. A receiver in a wireless communications system including a reverse link fundamental channel and a reverse link supplemental channel, said receiver comprising:

a delta computation module configured to produce a threshold delta;

a maintain and adjust threshold module configured to accept a frame erasure rate from said reverse link fundamental channel;

an adder configured to generate an outer-loop set point by adding a base threshold outputted by said maintain and adjust threshold module to said threshold delta outputted by said delta computation module;

a comparator configured to compare said outer-loop set point with a receive signal strength, an output of said comparator being utilized to adjust a transmit power of a mobile unit.

2. The receiver of claim 1 wherein said maintain and adjust threshold module is configured to accept said frame erasure rate from a reverse link dedicated control channel.

3. The receiver of claim 1 further comprising a generate up/down command module utilizing said output of said comparator to adjust said transmit power of said mobile unit.

4. The receiver of claim 1 wherein said threshold delta is substantially equal to a pilot reference level of a channel minus a pilot reference level of said reverse link fundamental channel.

5. The receiver of claim 1 wherein said threshold delta is set to zero when said reverse link supplemental channel is not received.

6. The receiver of claim 1 wherein said receive signal strength is outputted by a receive signal strength measurement module.

7. The receiver of claim 6 wherein said receive signal strength measurement module estimates a signal strength of a reverse link pilot channel.

8. The receiver of claim 1 wherein said maintain and adjust threshold module raises said base threshold by a Δ

up when a frame erasure occurs.

9. The receiver of claim 1 wherein said maintain and adjust threshold module lowers said base threshold by a Δ

down when a frame erasure does not occur.

10. The receiver of claim 1 wherein said maintain and adjust threshold module stores said base threshold.

11. A method for generating a target signal to noise and interference ratio in a receiver, said method comprising steps:

detecting a frame erasure from a reverse link fundamental channel;

measuring a frame erasure rate;

maintaining and adjusting a base threshold;

determining a threshold delta;

adding said threshold delta to said base threshold to produce a outer-loop set point.

12. The method of claim 11 further comprising a step of comparing a receive signal strength with said outer-loop set point.

13. The method of claim 12 further comprising a step of sending an up command to a mobile unit when said receive signal strength is less than said outer-loop set point.

14. The method of claim 12 further comprising a step of sending a down command to a mobile unit when said receive signal strength is greater than said outer-loop set point.

15. The method of claim 12 wherein said receive signal strength is determined from a reverse link pilot channel.

16. The method of claim 11 wherein said threshold delta is substantially equal to a pilot reference level of a maximum rate channel minus a pilot reference level of said reverse link fundamental channel.

17. The method of claim 11 wherein said detecting step comprises detecting said frame erasure from a reverse link dedicated control channel.

18. The method of claim 11 further comprising a step of determining when a mobile unit is transmitting using a plurality of channels.

19. The method of claim 18 wherein said threshold delta is set to zero when said mobile unit is not transmitting using said plurality of channels.

20. The method of claim 11 wherein said maintaining and adjusting threshold step comprises a step of raising said base threshold by a Δ

up when said frame erasure is detected.

21. The method of claim 11 wherein said maintaining and adjusting threshold step comprises a step of lowering said base threshold by a Δ

down when said frame erasure is not detected.