Weighted open loop power control

• US 6,956,889 B2
• Filed: 01/12/2004
• Issued: 10/18/2005
• Est. Priority Date: 03/21/2000
• Status: Expired due to Term

• Current Assignee: Apple Inc.
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Shin, Sung-Hyuk, Zeira, Ariela
• Primary Examiner(s): Ghebretinsae, Temesghen
• Application Number:
  US10/755,649
• Publication Number:
  US 20040141467A1
• Time in Patent Office: 645 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: H04B 2201/709709 Methods of preventing interference
• CPC Class Codes: H04W 52/10 Open loop power control
• CPC Class Codes: H04W 52/24 using SIR [Signal to Interference Ratio] or other wireless path parameters
• CPC Class Codes: H04W 52/242 taking into account path loss
• CPC Class Codes: H04W 52/246 where the output power of a terminal is based on a path parameter calculated in said terminal
• CPC Class Codes: H04W 52/248 where transmission power control commands are generated based on a path parameter

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 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 a 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; 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 a 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 estimtate.

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 transmit power calculation device for 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 to produce a weighted long term pathloss estimate, and determining a transmission power level of the time division duplex/code division multiple access user equipment by adding the weighted pathloss estimate to the weighted long term pathloss estimate to a measured interference level to a 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; and

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; 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 a 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.