User equipment using combined closed loop/open loop power control

• US 7,075,969 B2
• Filed: 05/24/2005
• Issued: 07/11/2006
• Est. Priority Date: 03/21/2000
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Shin, Sung-Hyuk, Zeira, Ariela, Ozluturk, Fatih M.
• Primary Examiner(s): PATEL, JAYANTI K
• Application Number:
  US11/136,239
• Publication Number:
  US 20050213636A1
• Time in Patent Office: 413 Days
• Field of Search: 375/130, 375/140, 375/295, 455/522, 455/69, 370/342, 370/252
• US Class Current: 375/130
• CPC Class Codes: H04B 2201/709709 Methods of preventing interference
• CPC Class Codes: H04W 52/08 Closed loop power control
• 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 52/241 taking into account channel quality metrics, e.g. SIR, SNR, CIR, Eb/lo
• CPC Class Codes: H04W 52/242 taking into account path loss
• CPC Class Codes: H04W 52/248 where transmission power control commands are generated based on a path parameter
• CPC Class Codes: H04W 52/265 taking into account the quality of service QoS
• CPC Class Codes: H04W 52/54 Signalisation aspects of the TPC commands, e.g. frame structure
• CPC Class Codes: H04W 52/60 using different transmission rates for TPC commands

Abstract

At a first communication station, communications from a second communication station are received. The first station transmits power commands based on in part a reception quality of the received communications. From the first communication station, a first communication having a transmission power level in a first time slot is transmitted. At the second communication station, the first communication and the power commands are received. A power level of the first communication as received is measured. A pathloss estimate is determined based on in part the measured received first communication power level and the first communication transmission power level. A transmission power level is set for a second communication in a second time slot from the second station to the first station based on in part the pathloss estimate weighted by a quality factor and the power commands.

Claims

1. A method for controlling transmission power levels in a spread spectrum time division duplex communication system having frames with time slots for communication, the method comprising:

receiving at a first communication station communications from a second communication station and transmitting from the first station power commands based on in part a reception quality of the received communications;

transmitting from the first communication station a first communication having a transmission power level in a first time slot;

receiving at the second communication station the first communication and the power commands;

measuring a power level of the first communication as received;

determining a pathloss estimate based on in part the measured received first communication power level and the first communication transmission power level; and

setting a transmission power level for a second communication in a second time slot from the second station to the first station based on in part the pathloss estimate weighted by a quality factor and the power commands.

2. The method of claim 1 wherein the set transmission power level is based on in part a desired received power level at the first station, a closed loop factor and an open loop factor;

wherein the closed loop factor is based on in part the received power commands and the open loop factor is based on in part the pathloss estimate weighted by the quality factor.

3. The method of claim 1 wherein the set transmission power level is based on in part a desired received power level at the first station and a combined closed loop/open loop factor;

wherein the combined closed loop/open loop factor is based on in part the received power commands and the pathloss estimate weighted by the quality factor.

4. The method of claim 2 wherein the closed loop factor is updated for each received power command.

5. The method of claim 3 wherein the combined factor is updated for each received power command.

6. The method of claim 2 wherein the desired received power level is based on in part a target signal to interference ratio and a measured interference level at the first station.

7. The method of claim 3 wherein the desired received power level is based on in part a target signal to interference ratio and a measured interference level at the first station.

8. The method of claim 1 wherein the first station is a base station and the second station is a user equipment.

9. The method of claim 1 wherein the first station is a user equipment and the second station is a base station.

10. A code division multiple access user equipment for controlling transmission power levels, the user equipment comprising:

means for receiving a first communication and power commands;

measuring a power level of the first communication as received;

determining a pathloss estimate based on in part the measured received first communication power level and a first communication transmission power level; and

setting a transmission power level for a second communication based on in part the pathloss estimate weighted by a quality factor and the power commands wherein said quality factor is determined based on in part a number of time slots, D, between a first and a second time slot.

11. The user equipment of claim 10 wherein the set transmission power level is based on in part a desired received power level, a closed loop factor and an open loop factor;

wherein the closed loop factor is based on in part the received power commands and the open loop factor is based on in part the pathloss estimate weighted by the quality factor.

12. The user equipment of claim 10 wherein the set transmission power level is based on in part a desired received power level at the first station and a combined closed loop/open loop factor;

wherein the combined closed loop/open loop factor is based on in part the received power commands and the pathloss estimate weighted by the quality factor.

13. The user equipment of claim 11 wherein the closed loop factor is updated for each received power command.

14. The user equipment of claim 12 wherein the combined factor is updated for each received power command.

15. The user equipment of claim 11 wherein the desired received power level is based on in part a target signal to interference ratio and a measured interference level.

16. The user equipment of claim 12 wherein the desired received power level is based on in part a target signal to interference ratio and a measured interference level.