Method and apparatus for managing power during a discontinuous reception mode

• US 7,680,071 B2
• Filed: 12/30/2005
• Issued: 03/16/2010
• Est. Priority Date: 09/16/2005
• Status: Expired due to Fees

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: DiFazio, Robert A., Bultan, Aykut, Haim, John W., Grieco, Donald M., Kearney, Kenneth P.
• Primary Examiner(s): Pérez-Gutiérrez; Rafael
• Assistant Examiner(s): Miah; Liton
• Application Number:
  US11/322,705
• Publication Number:
  US 20070064662A1
• Time in Patent Office: 1,537 Days
• Field of Search: 370/311, 455/572, 455/574
• US Class Current: 370/311
• CPC Class Codes: H04W 52/0225 using monitoring of external events, e.g. the presence of a signal
• CPC Class Codes: H04W 52/287 when the channel is in stand-by
• CPC Class Codes: H04W 52/44 in connection with interruption of transmission
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A method and apparatus for managing power during discontinuous reception (DRX) mode are disclosed. A DRX mode is defined for a wireless transmit/receive unit (WTRU) for reducing power consumption of the WTRU. During the DRX mode, the WTRU enters into a sleep state and periodically wakes up for processing paging blocks for detecting a paging indication for the WTRU and a corresponding paging message. If the WTRU is paged the WTRU terminates the DRX mode. If the WTRU is not paged, the WTRU reenters the sleep state. For power management during the DRX mode, a synchronization update period is defined. The synchronization update period is a period for performing automatic frequency correction and/or frame time correction.

Claims

1. A method for power management of a wireless transmit/receive unit (WTRU) during a discontinuous reception (DRX) mode comprising a plurality of DRX cycles, the method comprising:

entering a sleep state in accordance with a DRX cycle of the plurality of DRX cycles;

waking up responsive to a start of a synchronization update block for the WTRU to perform at least one of an automatic frequency correction (AFC) and frame time correction (FTC) during the DRX cycle, the synchronization update block comprising a plurality of frames designated for the WTRU performing the at least one of the AFC and the FTC,

receiving a beacon signal in the synchronization update block;

extracting midamble signal from the beacon signal; and

performing the at least one of the AFC and the FTC using the extracted midamble signal during the plurality of frames designated for the WTRU performing the at least one of the AFC and the FTC during the DRX cycle.

2. The method of claim 1 wherein the synchronization update block comprises 21 frames, whereby the AFC and the FTC are performed once in each synchronization update block by processing every fifth frame.

3. The method of claim 1 wherein if an AFC convergence is not declared at a beginning of a paging block following the synchronization update block, the AFC is performed during the paging block following the synchronization update block.

4. The method of claim 3 wherein the AFC is performed in every frame during the paging block following the synchronization update block until the AFC convergence is declared.

5. The method of claim 3 wherein if the AFC convergence is not declared at an end of the paging block following the synchronization update block, the AFC is performed during a following sleep state.

6. The method of claim 5 wherein the AFC is performed in every frame during the sleep state until the AFC convergence is declared.

7. The method of claim 1 wherein if a most significant path (MSP) valid is not declared at a beginning of a paging block following the synchronization update block, the FTC is performed during the paging block following the synchronization update block.

8. The method of claim 7 wherein the FTC is performed in every frame during the paging block following the synchronization update block until the MSP valid is declared.

9. The method of claim 7 wherein if the MSP valid is not declared at the end of the paging block following the synchronization update block, the FTC is performed during a following sleep state.

10. The method of claim 9 wherein the FTC is performed in every frame during the sleep state until the MSP valid is declared.

11. The method of claim 1 wherein a DRX cycle length which is a period between two consecutive paging blocks is one of 8, 16, 32, 64, 128, 256 and 526 frames.

12. The method of claim 1 wherein a period between two consecutive synchronization update blocks is 256 frames for DRX cycle lengths up to 256 frames and 512 frames for the DRX cycle length of 512 frames.

13. The method of claim 1 wherein before entering into the DRX mode, a last value of a voltage controlled oscillator (VCO) digital-to-analog converter (DAC) register is saved in a memory and used during the DRX mode.

14. The method of claim 1 wherein a radio power-up time is defined such that a temperature controlled crystal oscillator (TCXO) wakes up the radio power-up time before start of a frame that the WTRU needs to process.

15. The method of claim 14 wherein the radio power-up time is 5 ms.

16. The method of claim 14 wherein the radio power-up time is defined as one frame length.

17. The method of claim 1 wherein the beacon signals are signals transmitted via a primary common control physical channel (P-CCPCH).

18. The method of claim 1 wherein the AFC and the FTC are performed in the same time frame.

37. The method of claim 1, further comprising re-entering the sleep state responsive to finishing reading the beacon signal.

38. The method of claim 37, further comprising waking up from the sleep state periodically during the DRX cycle.

19. A wireless transmit/receive unit (WTRU) for power management during a discontinuous reception (DRX) mode comprising a plurality of DRX cycles, the WTRU comprising:

a plurality of power-consuming components;

a controller configured to;

turn off power to at least one of the power-consuming components in accordance with a DRX cycle of the plurality of DRX cycles and restore the power to the at least one of the power-consuming components responsive to a start of a synchronization update block for the WTRU during the DRX cycle to perform at least one of an automatic frequency correction (AFC) and frame time correction (FTC);

at least one of an AFC unit configured to perform the AFC during a synchronization update block after the controller has restored the power to the at least one of the power-consuming components, and

a FTC unit configured to perform the FTC during a synchronization update block after the controller has restored the power to the at least one of the power-consuming components,

the synchronization update block being a time period comprising a plurality of frames designated for the WTRU performing the at least one of the AFC and the FTC, and

at least one of the AFC and the FTC being performed using a midamble signal extracted from a beacon signal received in the synchronization update block during the plurality of frames designated for the WTRU performing the at least one of the AFC and the FTC during the DRX cycle.

20. The WTRU of claim 19 wherein the synchronization update block comprises 21 frames, whereby the AFC and the FTC are performed once in each synchronization update block by processing every fifth frame.

21. The WTRU of claim 19 wherein if an AFC convergence is not declared at a beginning of a paging block following the synchronization update block, the AFC unit runs the AFC during the paging block following the synchronization update block.

22. The WTRU of claim 21 wherein the AFC is performed in every frame during the paging block following the synchronization update block until the AFC convergence is declared.

23. The WTRU of claim 21 wherein if the AFC convergence is not declared at an end of the paging block following the synchronization update block, the AFC unit runs AFC during a following sleep state.

24. The WTRU of claim 23 wherein the AFC is performed in every frame during the sleep state until the AFC convergence is declared.

25. The WTRU of claim 19 wherein if a most significant path (MSP) valid is not declared by the FTC unit at a beginning of a paging block following the synchronization update block, the FTC unit runs FTC during the paging block following the synchronization update block.

26. The WTRU of claim 25 wherein the FTC is performed in every frame during the paging block following the synchronization update block until the MSP valid is declared by the FTC unit.

27. The WTRU of claim 25 wherein if the MSP valid is not declared by the FTC unit at the end of the paging block, the FTC unit runs FTC during a following sleep state.

28. The WTRU of claim 27 wherein the FTC is performed in every frame during the sleep state until the MSP valid is declared by the FTC unit.

29. The WTRU of claim 19 wherein a DRX cycle length which is a period between two consecutive paging Mocks is one of 8, 16, 32, 64, 128, 256 and 526 frames.

30. The WTRU of claim 19 wherein a period between two consecutive synchronization update blocks is 256 frames for DRX cycle lengths up to 256 frames and 512 frames for the DRX cycle length of 512 frames.

31. The WTRU of claim 19 wherein the AFC unit comprises a memory for storing a last value of a voltage controlled oscillator (VCO) digital-to-analog converter (DAC) register before entering into the DRX mode, whereby the stored value is used during the DRX mode.

32. The WTRU of claim 19 wherein a radio power-up time is defined such that a temperature controlled crystal oscillator (TCXO) wakes up a radio power-up time before a start of a frame that the AFC unit and the FTC unit need to process.

33. The WTRU of claim 32 wherein the radio power-up time is 5 ms.

34. The WTRU of claim 32 wherein the radio power-up time is defined as one frame length.

35. The WTRU of claim 19 wherein the beacon signals are signals transmitted via a primary common control physical channel (P-CCPCH).

36. The WTRU of claim 19 wherein the AFC unit and the FTC unit process a same frame.

39. The WTRU of claim 19, wherein the controller is further configured to turn off the power to the at least one of the power-consuming components responsive to finishing reading the beacon signal.

40. The WTRU of claim 39, wherein the controller is further configured to restore the power to the at least one power-consuming component periodically during the DRX cycle.