Apparatus and method for uplink power control of wireless communications

• US 8,107,987 B2
• Filed: 02/13/2008
• Issued: 01/31/2012
• Est. Priority Date: 02/14/2007
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Malladi, Durga Prasad, Montojo, Juan, Damnjanovic, Aleksandar, Ho, Sai Yiu Duncan
• Primary Examiner(s): SHARMA, SUJATHA R
• Application Number:
  US12/030,784
• Publication Number:
  US 20080200203A1
• Time in Patent Office: 1,448 Days
• Field of Search: 455/550.1, 455/553.1, 455/115.1, 455/127.1, 455/67.11, 455/522, 455/13.4, 370/328, 370/342, 370/311, 370/310, 370/329, 370/335, 370/318
• US Class Current: 455/522
• CPC Class Codes: H04W 52/287 when the channel is in stand-by
• CPC Class Codes: H04W 52/325 Power control of control or pilot channels
• CPC Class Codes: H04W 52/44 in connection with interruption of transmission

Abstract

Systems and methodologies are described that facilitate employing periodic closed loop power control corrections in a wireless communication environment. A periodic power control command can be sent over a downlink to control and/or correct an uplink power level employed by an access terminal. Each periodic power control command can be generated based upon an uplink periodic transmission sent from the access terminal. The periodic power control commands can be communicated via a Physical Downlink Control Channel (PDCCH) or in-band signaling. Moreover, access terminals can be grouped to enhance efficiency of downlink transfer of the periodic power control commands. The periodic power control commands can be halted upon access terminal uplink resources being deallocated. For instance, these resources can be deallocated after an inactivity period of the access terminal. Thereafter, the access terminal can initiate random access (e.g., leveraging open loop mechanisms) to resume periodic power control command transmission.

Claims

1. A method that facilitates generating periodic power control commands in a wireless communication environment, comprising:

transmitting periodic power control commands to an access terminal in response to received periodic signals from the access terminal;

deallocating uplink resources for the access terminal after an inactivity period of the access terminal;

adjusting an uplink power level when the access terminal resumes uplink transmissions; and

resuming transmission of periodic power control commands to the access terminal in response to received periodic signals from the access terminal.

2. The method of claim 1, wherein the periodic power control commands each include a single-bit correction.

3. The method of claim 1, wherein the periodic power control commands each include a multi-bit correction.

4. The method of claim 1, wherein the received periodic signals are periodic Sounding Reference Signal (SRS) transmissions.

5. The method of claim 1, wherein the received periodic signals are periodic Physical Uplink Control Channel (PUCCH) transmissions.

6. The method of claim 1, further comprising:

sampling a wireless communication system bandwidth based upon the received periodic signals irrespective of a transmission bandwidth of the access terminal at a given time; and

generating the periodic power control commands based upon the sampling of the wireless communication system bandwidth.

7. The method of claim 1, further comprising transmitting the periodic power control commands on a Physical Downlink Control Channel (PDCCH).

8. The method of claim 1, further comprising transmitting the periodic power control commands via in-band signaling.

9. The method of claim 1, further comprising:

grouping the access terminal with at least one disparate access terminal; and

transmitting periodic power control commands to access terminals in the group via a common Transmission Power Control-Physical Downlink Control Channel (TPC-PDCCH) transmission.

10. The method of claim 9, further comprising grouping the access terminal with at least one disparate access terminal based upon one or more of Discontinuous Reception (DRX) cycle, DRX phase, received periodic signal frequency, or Grade of Service (GoS) requirements.

11. The method of claim 1, wherein the inactivity period is at least one of predetermined or a threshold amount of time of inactivity by the access terminal.

12. The method of claim 1, further comprising:

verifying the access terminal through the resuming of the uplink transmissions; and

re-allocating the uplink resources to the access terminal.

13. The method of claim 1, wherein a frequency of the resumed transmission of periodic power control commands differs from a frequency of the periodic power control commands prior to deallocation of the uplink resources.

14. The method of claim 1, wherein a frequency of the resumed transmission of periodic power control commands is substantially similar to a frequency of the periodic power control commands prior to deallocation of the uplink resources.

15. The method of claim 1, further comprising transmitting aperiodic power control commands to the access terminal when needed while allocation and deallocation of the periodic power control commands are linked to existence of received periodic signals from the access terminal.

16. The method of claim 1, further comprising transmitting aperiodic power control commands to the access terminal, the aperiodic power control commands complement the periodic power control commands and are based on aperiodic transmissions on an uplink data channel.

17. A wireless communications apparatus, comprising:

a memory that retains instructions related to sending periodic power control commands to an access terminal in response to received periodic uplink transmissions from the access terminal, deallocating uplink resources for the access terminal after an inactivity period of the access terminal, controlling alteration of an uplink power level upon resuming of uplink transmissions from the access terminal, and resuming transfer of periodic power control commands to the access terminal in response to received periodic uplink transmissions from the access terminal; and

a processor, coupled to the memory, configured to execute the instructions retained in the memory.

18. The wireless communications apparatus of claim 17, wherein the received periodic uplink transmissions are periodic Sounding Reference Signal (SRS) transmissions.

19. The wireless communications apparatus of claim 17, wherein the received periodic uplink transmissions are periodic Physical Uplink Control Channel (PUCCH) transmissions.

20. The wireless communications apparatus of claim 17, wherein the memory further retains instruction related to sampling an overall system bandwidth based upon the received periodic uplink transmissions irrespective of a transmission bandwidth of the access terminal at a given time and generating the periodic power control commands based upon the sampling of the overall system bandwidth.

21. The wireless communications apparatus of claim 17, wherein the memory further retains instruction related to sending the periodic power control commands on a Physical Downlink Control Channel (PDCCH).

22. The wireless communications apparatus of claim 17, wherein the memory further retains instruction related to sending the periodic power control commands via in-band signaling.

23. The wireless communications apparatus of claim 17, wherein the memory further retains instruction related to grouping the access terminal with at least one disparate access terminal based upon one or more of Discontinuous Reception (DRX) cycle, DRX phase, received periodic uplink transmission frequency, or Grade of Service (GoS) requirements.

24. The wireless communications apparatus of claim 23, wherein the memory further retains instruction related to sending periodic power control commands to access terminals in the group via a common Transmission Power Control-Physical Downlink Control Channel (TPC-PDCCH) transmission.

25. The wireless communications apparatus of claim 17, wherein the inactivity period is at least one of predetermined or a threshold amount of time of inactivity by the access terminal.

26. The wireless communications apparatus of claim 17, wherein the memory further retains instruction related to verifying the access terminal through the resuming of the uplink transmissions and re-allocating the uplink resources to the access terminal.

27. The wireless communications apparatus of claim 17, wherein a frequency of the resumed transfer of periodic power control commands differs from a frequency of the periodic power control commands prior to deallocation of the uplink resources.

28. The wireless communications apparatus of claim 17, wherein the memory further retains instructions related to sending aperiodic power control commands to the access terminal while allocation and deallocation of the periodic power control commands are linked to existence of received periodic uplink transmissions.

29. The wireless communications apparatus of claim 17, wherein the memory further retains instructions related to sending aperiodic power control commands to the access terminal, the aperiodic power control commands complement the periodic power control commands and are based on aperiodic transmissions on an uplink data channel.

30. A wireless communications apparatus that enables yielding periodic power control commands for utilization by access terminals in a wireless communication environment, comprising:

means for sending periodic power control commands to an access terminal based upon evaluation of respective received periodic signals;

means for deallocating physical uplink resources for the access terminal after an inactivity period of the access terminal;

means for altering an uplink power level upon the access terminal resuming uplink transmissions; and

means for resuming transfer of periodic power control commands to the access terminal based on the received periodic signals.

31. The wireless communications apparatus of claim 30, wherein the received periodic signals are periodic Sounding Reference Signal (SRS) transmissions.

32. The wireless communications apparatus of claim 30, wherein the received periodic signals are periodic Physical Uplink Control Channel (PUCCH) transmissions.

33. The wireless communications apparatus of claim 30, further comprising:

means for sampling an overall system bandwidth based upon the received periodic signals irrespective of a transmission bandwidth of the access terminal at a particular time; and

means for generating the periodic power control commands based upon the sampling of the overall system bandwidth.

34. The wireless communications apparatus of claim 30, further comprising means for sending the periodic power control commands on a Physical Downlink Control Channel (PDCCH).

35. The wireless communications apparatus of claim 30, further comprising means for sending the periodic power control commands via in-band signaling.

36. The wireless communications apparatus of claim 30, further comprising:

means for grouping the access terminal with at least one disparate access terminal based upon one or more of Discontinuous Reception (DRX) cycle, DRX phase, received periodic signal frequency, or Grade of Service (GoS) requirements; and

means for sending periodic power control commands to access terminals in the group via a common Transmission Power Control-Physical Downlink Control Channel (TPC-PDCCH) transmission.

37. The wireless communications apparatus of claim 30, wherein the inactivity period is at least one of predetermined or a threshold amount of time of inactivity by the access terminal.

38. The wireless communications apparatus of claim 30, wherein a frequency of the resumed transfer of periodic power control commands differs from a frequency of the periodic power control commands prior to deallocation of the physical uplink resources.

39. The wireless communications apparatus of claim 30, further comprising means for sending aperiodic power control commands to the access terminal when needed, the aperiodic power control commands complement the periodic power control commands and are based on aperiodic transmissions on an uplink data channel.

40. A machine-readable medium having stored thereon machine-executable instructions for:

transmitting periodic power control commands to an access terminal in response to received periodic uplink transmissions from the access terminal;

deallocating uplink resources for the access terminal after an inactivity period of the access terminal;

controlling alteration of an uplink power level upon resuming of uplink transmissions from the access terminal; and

resuming transmission of periodic power control commands to the access terminal in response to received periodic uplink transmissions from the access terminal.

41. The machine-readable medium of claim 40, wherein the received periodic uplink transmissions are periodic Sounding Reference Signal (SRS) transmissions.

42. The machine-readable medium of claim 40, wherein the received periodic uplink transmissions are periodic Physical Uplink Control Channel (PUCCH) transmissions.

43. The machine-readable medium of claim 40, the machine-executable instructions further comprise sampling an overall system bandwidth based upon the received periodic uplink transmissions irrespective of a transmission bandwidth of the access terminal at a particular time, and yielding the periodic power control commands based upon the sampling of the overall system bandwidth.

44. The machine-readable medium of claim 40, the machine-executable instructions further comprise transmitting the periodic power control commands on a Physical Downlink Control Channel (PDCCH).

45. The machine-readable medium of claim 40, the machine-executable instructions further comprise transmitting the periodic power control commands by way of in-band signaling.

46. The machine-readable medium of claim 40, the machine-executable instructions further comprise grouping the access terminal with at least one disparate access terminal based upon one or more of Discontinuous Reception (DRX) cycle, DRX phase, received periodic uplink transmission frequency, or Grade of Service (GoS) requirements, and transmitting periodic power control commands to access terminals in the group via a common Transmission Power Control-Physical Downlink Control Channel (TPC-PDCCH) transmission.

47. The machine-readable medium of claim 40, wherein the inactivity period is at least one of predetermined or a threshold amount of time of inactivity by the access terminal.

48. The machine-readable medium of claim 40, wherein a frequency of the resumed transmission of periodic power control commands differs from a frequency of the periodic power control commands prior to deallocation of the physical uplink resources.

49. The machine-readable medium of claim 40, the machine-executable instructions further comprise transmitting aperiodic power control commands to the access terminal when needed while allocation and deallocation of the periodic power control commands are linked to existence of received periodic uplink transmissions.

50. The machine-readable medium of claim 40, the machine-executable instructions further comprise transmitting aperiodic power control commands to the access terminal, the aperiodic power control commands complement the periodic power control commands and are based on aperiodic transmissions on an uplink data channel.

51. In a wireless communications system, an apparatus comprising:

a processor configured to;

transmit periodic power control commands to an access terminal in response to received periodic signals from the access terminal;

deallocate uplink resources for the access terminal after an inactivity period of the access terminal;

control adjustment of an uplink power level when the access terminal resumes uplink transmissions; and

restart transmission of periodic power control commands to the access terminal in response to received periodic signals from the access terminal.

52. A method that facilitates utilizing periodic power control commands in a wireless communication environment, comprising:

sending periodic transmissions over an uplink;

receiving periodic power control commands in response to each of the periodic transmissions;

transitioning to a state where uplink dedicated resources are released;

resuming uplink transmission; and

resuming the periodic transmissions over the uplink and receipt of the responsive, periodic power control commands.

53. The method of claim 52, wherein the periodic transmissions are periodic Sounding Reference Signal (SRS) transmissions.

54. The method of claim 52, wherein the periodic transmissions are periodic Physical Uplink Control Channel (PUCCH) transmissions.

55. The method of claim 52, further comprising sending the periodic transmissions over the uplink at respective uplink power levels, the respective uplink power levels being adjusted based upon the responsive, periodic power control commands.

56. The method of claim 52, further comprising receiving the periodic power control commands on a Physical Downlink Control Channel (PDCCH).

57. The method of claim 52, further comprising receiving the periodic power control commands as part of Transmission Power Control-Physical Downlink Control Channel (TPC-PDCCH) transmissions allocated to a group associated with an access terminal, wherein the group includes one or more disparate access terminals in addition to the access terminal.

58. The method of claim 52, further comprising receiving the periodic power control commands via in-band signaling.

59. The method of claim 52, further comprising transitioning to the state where the uplink dedicated resources are released in response to an inactivity period.

60. The method of claim 52, further comprising employing an open loop estimate of a power level at the resuming of the uplink transmission.

61. The method of claim 52, further comprising receiving aperiodic power control commands in addition to the periodic power control commands, the aperiodic power control commands complement the periodic power control commands and are based on aperiodic transmissions on an uplink data channel.

62. A wireless communications apparatus, comprising:

a memory that retains instructions related to transferring periodic transmissions over an uplink, obtaining periodic power control commands each generated based upon the periodic transmissions, transitioning to a state where uplink dedicated resources are released from an access terminal, resuming uplink transmission, and restarting the periodic transmissions over the uplink and receipt of the periodic power control commands; and

a processor, coupled to the memory, configured to execute the instructions retained in the memory.

63. The wireless communications apparatus of claim 62, wherein the periodic transmissions are periodic Sounding Reference Signal (SRS) transmissions.

64. The wireless communications apparatus of claim 62, wherein the periodic transmissions are periodic Physical Uplink Control Channel (PUCCH) transmissions.

65. The wireless communications apparatus of claim 62, wherein the memory further retains instructions related to transferring the periodic transmissions over the uplink at respective uplink power levels, the respective uplink power levels being controlled based upon the periodic power control commands.

66. The wireless communications apparatus of claim 62, wherein the memory further retains instructions related to obtaining the periodic power control commands on a Physical Downlink Control Channel (PDCCH).

67. The wireless communications apparatus of claim 62, wherein the memory further retains instructions related to obtaining the periodic power control commands as part of Transmission Power Control-Physical Downlink Control Channel (TPC-PDCCH) transmissions allocated to a group associated with the access terminal, wherein the group includes one or more disparate access terminals in addition to the access terminal.

68. The wireless communications apparatus of claim 62, wherein the memory further retains instructions related to obtaining the periodic power control commands via in-band signaling.

69. The wireless communications apparatus of claim 62, wherein the memory further retains instructions related to transitioning to the state where the uplink dedicated resources are released based upon an occurrence of an inactivity period.

70. The wireless communications apparatus of claim 62, wherein the memory further retains instructions related to employing an open loop estimate of a power level at the resuming of the uplink transmission.

71. The wireless communications apparatus of claim 62, wherein the memory further retains instructions related to obtaining aperiodic power control commands in addition to the periodic power control commands, the aperiodic power control commands complement the periodic power control commands and are based on aperiodic transmissions on an uplink data channel.

72. A wireless communications apparatus that enables utilizing periodic power control commands in a wireless communication environment, comprising:

means for transferring periodic transmissions over an uplink to obtain respective, periodic power control commands in response;

means for switching to a state where physical uplink dedicated resources are released;

means for resuming uplink transmission; and

means for resuming the periodic transmissions over the uplink and receipt of the respective, periodic power control commands.

73. The wireless communications apparatus of claim 72, wherein the periodic transmissions are periodic Sounding Reference Signal (SRS) transmissions.

74. The wireless communications apparatus of claim 72, wherein the periodic transmissions are periodic Physical Uplink Control Channel (PUCCH) transmissions.

75. The wireless communications apparatus of claim 72, further comprising means for transferring the periodic transmissions over the uplink at respective uplink power levels, the respective uplink power levels being controlled based upon the periodic power control commands.

76. The wireless communications apparatus of claim 72, further comprising means for obtaining the respective, periodic power control commands on a Transmission Power Control-Physical Downlink Control Channel (TPC-PDCCH) as part of TPC-PDCCH transmissions allocated to a group associated with an access terminal.

77. The wireless communications apparatus of claim 72, further comprising means for obtaining the respective, periodic power control commands via in-band signaling.

78. The wireless communications apparatus of claim 72, further comprising means for switching to the state where the physical uplink dedicated resources are released based upon an occurrence of an inactivity period.

79. The wireless communications apparatus of claim 72, further comprising means for estimating a power level to utilize for the resuming of the uplink transmission based at least in part upon an open loop mechanism.

80. The wireless communications apparatus of claim 72, further comprising means for obtaining aperiodic power control commands in addition to the respective, periodic power control commands, the aperiodic power control commands complement the respective, periodic power control commands and are based on aperiodic transmissions on an uplink data channel.

81. A machine-readable medium having stored thereon machine-executable instructions for:

transferring periodic Sounding Reference Signal (SRS) transmissions over an uplink;

obtaining periodic power control commands each generated based upon the periodic transmissions;

transitioning to a state where uplink dedicated resources are released from an access terminal;

resuming uplink transmission; and

restarting the periodic transmissions over the uplink and receipt of the periodic power control commands.

82. The machine-readable medium of claim 81, the machine-executable instructions further comprise transferring the periodic SRS transmissions over the uplink at respective uplink power levels, the respective uplink power levels being controlled based upon the periodic power control commands.

83. The machine-readable medium of claim 81, the machine-executable instructions further comprise obtaining the periodic power control commands on a Transmission Power Control-Physical Downlink Control Channel (TPC-PDCCH) as part of TPC-PDCCH transmissions allocated to a group associated with the access terminal.

84. The machine-readable medium of claim 81, the machine-executable instructions further comprise obtaining the periodic power control commands via in-band signaling.

85. The machine-readable medium of claim 81, the machine-executable instructions further comprise transitioning to the state where the uplink dedicated resources are released based upon an occurrence of an inactivity period.

86. The machine-readable medium of claim 81, the machine-executable instructions further comprise estimating a power level to utilize at the resuming of the uplink transmission based at least in part upon an open loop mechanism.

87. The machine-readable medium of claim 81, the machine-executable instructions further comprise obtaining aperiodic power control commands in addition to the periodic power control commands, the aperiodic power control commands complement the periodic power control commands and are based on aperiodic transmissions on an uplink data channel.

88. In a wireless communications system, an apparatus comprising:

a processor configured to;

send periodic transmissions over an uplink;

receive periodic power control commands in response to each of the periodic transmissions;

transition to a state where uplink dedicated resources are released;

resume uplink transmission; and

resume the periodic transmissions over the uplink and receipt of the responsive, periodic power control commands.