Combined open loop/closed loop method for controlling uplink power of a mobile station

• US 8,812,048 B2
• Filed: 07/08/2013
• Issued: 08/19/2014
• Est. Priority Date: 03/07/2007
• Status: Active Grant

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Shin, Sung-Hyuk, Lin, Zinan, Grieco, Donald M., Olesen, Robert L.
• Primary Examiner(s): Safaipour, Bobbak
• Application Number:
  US13/936,846
• Publication Number:
  US 20130295979A1
• Time in Patent Office: 407 Days
• Field of Search: 455/522, 370/318, 375/130, 375/259, 375/222, 375/295, 375/219, 375/220, 375/275
• US Class Current: 455/522
• CPC Class Codes: H04L 1/1812 Hybrid protocols; Hybrid automatic repeat request [HARQ]
• CPC Class Codes: H04W 52/06 TPC algorithms
• CPC Class Codes: H04W 52/08 Closed loop power control
• CPC Class Codes: H04W 52/10 Open loop power control
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/242 taking into account path loss
• CPC Class Codes: H04W 76/28 Discontinuous transmission [DTX]; Discontinuous reception [DRX]

Abstract

A method and apparatus are disclosed comprising a combined open loop/closed loop uplink power control scheme for E-UTRA. The combined open and closed loop method for UL intra-cell PC controls the wireless transmit receive unit (WTRU) transmit power spectral density (PSD), PSD_Tx, (e.g. power per RB).

Claims

1. A method for controlling transmit power of a wireless transmit/receive unit (WTRU) comprising:

determining an open loop uplink (UL) power control (PC) component based on pathloss measurement;

determining a closed loop PC component including a correction factor, wherein the correction factor is based on a PC correction command signaled in a UL grant associated with a hybrid automatic repeat request (HARQ) process;

combining the open loop component and the closed loop PC component with a delta factor related to an offset value to determine a transmit power, wherein the offset value is related to a modulation coding set (MCS); and

applying the transmit power in accordance with a timing of the HARQ process.

2. The method of claim 1, further comprising:

receiving the PC correction command.

3. The method of claim 2, wherein the PC correction command is received in a pre-configured signaling time.

4. The method of claim 1, wherein the open loop PC component is based on the pathloss variation.

5. The method of claim 4, wherein the pathloss variation is a variation between the pathloss prior to a discontinuous transmission and a time before resuming an UL transmission.

6. The method of claim 1, wherein the PC correction command comprises multiple command bits determined based on link quality.

7. The method of claim 1, wherein applying the transmit power in accordance with a timing of the HARQ process comprises:

applying the transmit power to the beginning of a next uplink transmit time interval (TTI) until a next transmit power update.

8. The method of claim 1, wherein the correction factor is zero (0) in an initial uplink transmission.

9. The method of claim 1, further comprising:

determining an interference load indicator the interference loud indicator determined from a strongest neighboring cell.

10. The method of claim 9, wherein the transmit power is based on a downlink reference signal wherein the interference load indicator is used to mitigate inter-cell interference.

21. The method of claim 2, wherein the open loop PC component comprises a cell-specific parameter.

22. The method of claim 21, wherein the cell-specific parameter is provided from higher layers.

23. The method of claim 21, wherein the open loop PC component comprises a WTRU-specific parameter.

24. The method of claim 23, wherein the WTRU-specific parameter is provided from higher layers.

25. The method of claim 2, wherein the open loop PC component comprises a WTRU-specific parameter.

26. The method of claim 25, wherein the WTRU-specific parameter is provided from higher layers.

27. The method of claim 1, wherein applying the transmit power in accordance with a timing of the HARQ process comprises:

applying the transmit power after one HARQ cycle time.

11. A wireless transmit/receive unit (WTRU) comprising a processor, wherein the processor is configured to:

determine an open loop uplink (UL) power control (PC) component based on pathloss measurement;

determine a closed loop PC component including a correction factor, wherein the correction factor is based on a PC correction command signaled in a UL grant associated with a hybrid automatic repeat request (HARQ) process;

combine the open loop component and the closed loop PC component with a delta factor related to offset value to determine a WTRU transmit power, wherein the offset value is related to a modulation coding set (MCS); and

apply the transmit power in accordance with a timing of the HARQ process.

12. The WTRU of claim 11, further comprising:

a receiver for receiving the PC correction.

13. The WTRU of claim 12, wherein the PC correction command is received in a pre-configured signaling time.

14. The WTRU of claim 11, wherein the open loop PC component is based on a pathloss variation.

15. The WTRU of claim 14, wherein the pathloss variation is a variation between the pathloss prior to a discontinuous transmission (DTX) and a time before resuming an UL transmission.

16. The WTRU of claim 11, wherein the PC correction command comprises multiple command bits determined based on link quality.

17. The WTRU of claim 11, wherein:

the transmit power is applied to the beginning of a next uplink transmit time interval (TTI) until a next transmit power update.

18. The WTRU of claim 11, wherein the correction factor is zero (0) in an initial uplink transmission.

19. The WTRU of claim 11, wherein the processor determines an interference load indicator the interference load indicator determined from a strongest neighboring cell.

20. The WTRU of claim 19, wherein the transmit power is based on a downlink reference signal wherein the interference loud indicator is used to mitigate inter-cell interference.

28. The WTRU of claim 12, wherein the open loop PC component comprises a cell-specific parameter.

29. The WTRU of claim 28, wherein the cell-specific parameter is provided from higher layers.

30. The WTRU of claim 28, wherein the open loop PC component comprises a WTRU-specific parameter.

31. The WTRU of claim 30, wherein the WTRU-specific parameter is provided from higher layers.

32. The WTRU of claim 12, wherein the open loop PC component comprises a WTRU-specific parameter.

33. The WTRU of claim 32, wherein the WTRU-specific parameter is provided from higher layers.

34. The WTRU of claim 12, wherein the transmit power is applied after one HARQ cycle time.

35. A method implemented by an eNode-B for use with controlling transmit power of a wireless transmit/receive unit (WTRU), the method comprising:

transmitting any of a cell-specific parameter and WTRU-specific parameter for determining an open loop uplink (UL) power control (PC) component as a function of pathloss;

transmitting a PC correction command; and

receiving, from the WTRU, a transmission having an applied transmit power, wherein the applied transmit power comprises a combination of the open loop PC component, a closed loop PC component and a delta factor related to an offset value, wherein the offset value is related to a modulation coding set (MCS), wherein the closed loop PC component includes a correction factor, and wherein the correction factor is based on the PC correction command.

36. The method of claim 35, wherein the PC correction command is transmitted in a UL grant associated with a hybrid automatic repeat request (HARQ) process.

37. The method of claim 36, wherein the received transmission with applied transmission power is received in accordance with a timing of the HARQ process.

38. The method of claim 35, wherein the PC correction command is transmitted at a pre-configured signaling time.

39. The method of claim 35, wherein the cell-specific parameter is provided from higher layers.

40. The method of claim 35, wherein the WTRU-specific parameter is provided from higher layers.

41. An eNode-B for use with controlling transmit power of a wireless transmit/receive unit (WTRU), the eNode-B comprising a transmitter and a receiver, wherein:

the transmitter is configured to transmit any of a cell-specific parameter and WTRU-specific parameter for determining an open loop uplink (UL) power control (PC) component as a function of pathloss;

the transmitter is configured to transmit a PC correction command; and

the receiver is configured to receive, from the WTRU, a transmission having an applied transmit power, wherein the applied transmit power comprises a combination of the open loop PC component, a closed loop PC component and a delta factor related to an offset value, wherein the offset value is related to a modulation coding set (MCS), wherein the closed loop PC component includes a correction factor, and wherein the correction factor is based on the PC correction command.

42. The eNode-B of claim 41, wherein the transmitter is configure to transmit the PC correction command in a UL grant associated with a hybrid automatic repeat request (HARQ) process.

43. The eNode-B of claim 42, wherein the receiver is configured to receive the transmission with applied transmission power in accordance with a timing of the HARQ process.

44. The eNode-B of claim 41, wherein the transmitter is configured to transmit the PC correction command at a pre-configured signaling time.

45. The eNode-B of claim 41, wherein the cell-specific parameter is provided from higher layers.

46. The eNode-B of claim 41, wherein the WTRU-specific parameter is provided from higher layers.