Outer loop/weighted open loop power control

• US 6,993,063 B2
• Filed: 01/12/2004
• Issued: 01/31/2006
• Est. Priority Date: 03/22/2000
• Status: Expired due to Term

• Current Assignee: Apple Inc.
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Shin, Sung-Hyuk, Dick, Stephen G., Zeira, Ariela
• Primary Examiner(s): Ghebretinsae, Temesghen
• Application Number:
  US10/755,759
• Publication Number:
  US 20040141483A1
• Time in Patent Office: 750 Days
• Field of Search: 375/130, 375/295, 375/146, 370/347, 370/318, 370/342, 455/522, 455/69
• US Class Current: 375/130
• CPC Class Codes: H04W 52/12 Outer and inner loops
• CPC Class Codes: H04W 52/225 Calculation of statistics, e.g. average, variance
• CPC Class Codes: H04W 52/24 using SIR [Signal to Interference Ratio] or other wireless path parameters

Abstract

A transmission power level for a user equipment in a wireless time division duplex communication system using code division multiple access is determined. An interference level is measured. A pathloss estimate is determined. A long term average of pathloss estimates is determined. A first weighting factor, α, is determined by the determined pathloss estimate, producing a weighted pathloss estimate. (1−α) is multiplied to the determined long term average of pathloss estimates, producing a weighted long term pathloss estimate. A target signal to interference ratio is provided. The target signal to interference ratio is updated using outer loop power commands. A transmission power level of the user equipment is determined by adding the weighted pathloss estimate to the weighted long term pathloss estimate to the measured interference level to the updated target signal to interference ratio to a constant value.

Claims

1. A method for transmission power control of a user equipment in a wireless time division duplex communication system using code division multiple access, the method comprising:

measuring an interference level;

determining a pathloss estimate;

determining a long term average of pathloss estimates; and

multiplying a first weighting factor, α

, by the determined pathloss estimate, producing a weighted pathloss estimate;

multiplying (1−

α

) to the determined long term average of pathloss estimates, producing a weighted long term pathloss estimate;

providing a target signal to interference ratio;

updating the target signal to interference ratio using outer loop power commands; and

determining a transmission power level of the user equipment by adding the weighted pathloss estimate to the weighted long term pathloss estimate to the measured interference level to the updated target signal to interference ratio to a constant value.

2. The method of claim 1 wherein the first weighting factor represents a quality of the pathloss estimate.

3. The method of claim 1 wherein the determining the pathloss estimate is by subtracting a received power level from a transmit power level signaled on a broadcast channel.

4. A time division duplex/code division multiple access user equipment comprising:

a pathloss estimation device for determining a pathloss estimate;

a target update device for updating a target signal to interference ratio using outer loop power commands;

a transmit power calculation device for measuring an interference level, determining a long term average of pathloss estimates, multiplying a first weighting factor, α

, by the determined pathloss estimate, producing a weighted pathloss estimate, multiplying (1−

α

) to the determined long term average of pathloss estimates, producing a weighted long term pathloss estimate, determining a transmission power level of the user equipment by adding the weighted pathloss estimate to the weighted long term pathloss estimate to the measured interference level to the updated target signal to interference ratio to a constant value.

5. The time division duplex/code division multiple access user equipment of claim 4 wherein the first weighting factor represents a quality of the pathloss estimate.

6. The time division duplex/code division multiple access user equipment of claim 4 wherein the determining the pathloss estimate is by subtracting a received power level from a transmit power level signaled on a broadcast channel.

7. A time division duplex/code division multiple access user equipment comprising:

means for measuring an interference level;

means for determining a pathloss estimate;

means for determining a long term average of pathloss estimates;

means for multiplying a first weighting factor, α

, by the determined pathloss estimate, producing a weighted pathloss estimate;

means for multiplying (1−

α

) to the determined long term average of pathloss estimates, producing a weighted long term pathloss estimate;

means for providing a target signal to interference ratio and updating the target signal to interference ratio using outer loop power commands; and

means for determining a transmission power level of the user equipment by adding the weighted pathloss estimate to the weighted long term pathloss estimate to the measured interference level to the updated target signal to interference ratio to a constant value.

8. The time division duplex/code division multiple access user equipment of claim 7 wherein the first weighting factor represents a quality of the pathloss estimate.

9. The time division duplex/code division multiple access user equipment of claim 7 wherein the determining the pathloss estimate is by subtracting a received power level from a transmit power level signaled on a broadcast channel.