Method of employing weighted open loop power control in a base station

• US 6,584,139 B2
• Filed: 02/26/2002
• Issued: 06/24/2003
• 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:
  US10/083,212
• Publication Number:
  US 20020080766A1
• Time in Patent Office: 483 Days
• Field of Search: 375/130, 375/140, 375/295, 370/318, 370/347, 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

The method employing weighted open loop power control in a base station is initiated by the base station receiving a communication and measuring its received power level. Based on, in part, the received communication'"'"'s power level and the communication'"'"'s transmission power level, a path loss estimate is determined. A quality of the path loss estimate is also determined. The transmission power level for a communication from the base station is based, in part, on weighting the path loss estimate in response to the quality of the estimate.

Claims

1. A method for operating a base station for controlling transmission power levels using a spread spectrum time division duplex technique having frames with time slots for communication, comprising:

a) receiving, in a first time slot, a first communication including a transmission power level;

b) measuring a power level of the first communication;

c) determining a path loss estimate based in part on the power level determined at step (b) and the transmission power level obtained at step (a);

d) determining a long term path loss estimate based on prior received path loss estimates;

e) setting a transmission power level for a second communication in a second time slot based in part on the path loss estimate weighted by a first factor and the long term path loss estimate weighted by a second factor, wherein the first and second factors are a function of a time separation between the first and second time slots; and

f) determining a quality, α

, of the pathloss estimate based in part on a number of time slots, D, between the first and second time slot; and

wherein the first factor is α and

the second factor is 1-α

.

2. The method of claim 1 wherein step (d) further comprises:

basing the long term path loss estimate at least in part upon an average of path loss estimates of prior communications received by the base station.

3. The method of claim 1 wherein a maximum time slot delay is D_max and the determined quality, α

, is determined by;

4. The method of claim 1 wherein a maximum allowed time slot delay is D_max-allowed and the determined quality, α

, is determined by;

5. A method for operating a base station for controlling transmission power levels using a spread spectrum time division duplex technique having frames with time slots for communication, comprising:

a) receiving, in a first time slot, a first communication including a reference for a transmission power level;

b) measuring a power level of the first communication;

c) determining a reference level for a path loss estimate based in part on the power level determined at step (b) and the transmission power level obtained at step (a);

d) determining a reference for a long term path loss estimate based on at least in part upon an average of path loss estimates of prior communications received by the base station; and

e) setting a transmission power level for a second communication in a second time slot based in part on the path loss estimate weighted by a first factor and the long term path loss estimate weighted by a second factor, wherein the first and second factors are a function of time separation of the first and second time slots.