LTE-U UPLINK WAVEFORM AND VARIABLE MULTI-SUBFRAME SCHEDULING

• US 20150085797A1
• Filed: 09/22/2014
• Published: 03/26/2015
• Est. Priority Date: 09/23/2013
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Ji, Tingfang, Luo, Tao, Bhushan, Naga, Malladi, Durga Prasad, Wei, Yongbin, Gaal, Peter, Damnjanovic, Aleksandar, Chen, Wanshi, Yerramalli, Srinivas
• Granted Patent: US 9,743,432 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04J 13/10 Code generation
• CPC Class Codes: H04J 3/16 in which the time allocation to individual channels within a transmission cycle is variable, e.g. to accommodate varying complexity of signals, to vary number of channels transmitted H04J3/17, H04J3/24 take precedence
• CPC Class Codes: H04L 5/0041 Frequency-non-contiguous
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0094 Indication of how sub-channels of the path are allocated
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 74/002 Transmission of channel access control information
• CPC Class Codes: H04W 74/0866 using a dedicated channel for access

Abstract

Uplink waveforms for operating long term evolution (LTE) in an unlicensed band (i.e., long term evolution-unlicensed (LTE-U) communication) are disclosed. Carrier aggregation (CA) and standalone (SA) are disclosed. LTE on the licensed channel may provide both control and data, LTE on the unlicensed channel may provide data. Managing variable transmission time interval (TTI) continuous transmission is disclosed for transmission over multiple subframes of an unlicensed carrier in LTE-U. Listen-before-talk (LBT) requirements of unlicensed carriers provide for additional channel occupancy constraints when scheduling resources for multiple UEs for variable TTI continuous uplink transmissions over multiple subframes. A joint control channel is disclosed that provides control information for all of the potentially available subframes to be scheduled for the uplink transmissions. In addition to management of the variable TTI continuous transmissions, adjustments to uplink signal parameters are also disclosed that address the constraints due to the LBT requirements of unlicensed carriers.

Claims

1. A method for wireless communication operable by a mobile device, the method comprising:

determining a uplink resource block configuration comprising at least one set of resource blocks uniformly distributed in a portion of a bandwidth occupying at least a minimum predetermined bandwidth threshold; and

sending a transmission in the at least one set of the resource blocks.

2. The method of claim 1, wherein the said minimum predetermined bandwidth threshold is the same for all mobile devices served by a base station.

3. The method of claim 2, wherein the said minimum predetermined bandwidth threshold is signaled in a broadcast message.

4. The method of claim 1, wherein each of the at least one set of resource blocks is assigned to one of a PUSCH, PUCCH, or PRACH over one subframe.

5. The method of claim 1, wherein sending the transmission comprises sending at least one of a sound reference signal (SRS), channel utilization beacon signal (CUBS) in the at least one set of the resource blocks over a plurality of OFDM symbols.

6. The method of claim 1, wherein the at least one resource block comprises orthogonal sets of resource blocks allocated to a plurality of mobile devices.

7. The method of claim 1, wherein the at least one resource block comprises orthogonal sets of resource blocks, each set assigned to a plurality of mobile devices, with a PUSCH being spatially multiplexed among the mobile devices, and at least one of a PDCCH, SRS, PRACH, being code division multiplexed among the mobile devices.

8. The method of claim 1, further comprising receiving an assignment of one of an SRS or CUBS for transmission on the at least one set of the resource blocks;

and wherein

code sequences for SRS and CUBS are partitioned; and

code sequences for CUBS from multiple UEs are not orthogonal.

9. The method of claim 8, further comprising transmitting at least one of a PRACH transmission or SRS in a set of resource blocks reserved for the PRACH transmission or SRS.

10. The method of claim 1, wherein the uplink resource block configuration is based on an orthogonal frequency division multiplexing.

11. An apparatus comprising:

means for determining a uplink resource block configuration comprising at least one set of resource blocks uniformly distributed in a portion of a bandwidth occupying at least a minimum predetermined bandwidth threshold; and

means for sending a transmission in the at least one set of the resource blocks.

12. An apparatus comprising:

at least one processor configured for determining a uplink resource block configuration comprising at least one set of resource blocks uniformly distributed in a portion of a bandwidth occupying at least a minimum predetermined bandwidth threshold;

a transceiver configured for sending a transmission in the at least one set of the resource blocks; and

a memory coupled to the at least one processor for storing data.

13. A computer program product comprising:

computer-readable medium storing code for causing at least one computer to;

determine a uplink resource block configuration comprising at least one set of resource blocks uniformly distributed in a portion of a bandwidth occupying at least a minimum predetermined bandwidth threshold; and

send a transmission in the at least one set of the resource blocks.

14. A method for wireless communication operable by a mobile device, the method comprising:

broadcasting an indication comprising a channel use beacon signal (CUBS) transmission for channel utilization in response to detecting a clear channel in a clear channel assessment (CCA) occasion, wherein the clear channel is defined as an energy level below a threshold or no detection of a CUBS signal; and

continuously transmitting on at least one subframe succeeding the CUBS transmission.

15. The method of claim 14, wherein the CCA occasion occupies a fraction of an OFDM symbol duration;

and

the CUBS transmission is aligned to a predetermined OFDM symbol boundary.

16. The method in claim 15, wherein the first CCA occasion is one of multiple successive occasions and the assigned CCA occasion is based on a group membership.

17. The method of claim 16, wherein the group membership is a PLMN membership.

18. The method of claim 14, wherein the channel utilization occasion comprises at least a portion of a multiuse subframe, and the remainder of the multiuse subframe is reserved for downlink transmissions, CUBS transmission and guard period.

19. The method of claim 14, wherein the indication for channel utilization is based on an assigned SRS.

20. An apparatus comprising:

means for broadcasting an indication comprising a channel use beacon signal (CUBS) transmission for channel utilization in response to detecting a clear channel in a clear channel assessment (CCA) occasion, wherein the clear channel is defined as energy level below a threshold or no detection of a CUBS signal; and

means for continuously transmitting on at least one subframe succeeding the CUBS transmission.

21. An apparatus comprising:

a transceiver configured for broadcasting an indication comprising a channel use beacon signal (CUBS) transmission for channel utilization in response to detecting a clear channel in a clear channel assessment (CCA) occasion, wherein the clear channel is defined as energy level below a threshold or no detection of a CUBS signal, and continuously transmitting on at least one subframe succeeding the CUBS transmission; and

a memory coupled to the at least one processor for storing data.

22. A computer program product comprising:

computer-readable medium storing code for causing at least one computer to;

broadcast an indication comprising a channel use beacon signal (CUBS) transmission for channel utilization in response to detecting a clear channel in a clear channel assessment (CCA) occasion, wherein a clear channel is defined as energy level below a threshold or no detection of CUBS signal; and

continuously transmit on at least one subframe succeeding the CUBS transmission.

23. A method for wireless communication operable by a mobile device, the method comprising:

determining a uplink resource block configuration comprising at least a first set of dynamically scheduled resource blocks and at least a second resource block over a predetermined set of resource blocks on the edge of the channel bandwidth, the resource block configuration occupying at least a minimum predetermined bandwidth threshold; and

sending a transmission in the at least one of the resource block in the first set and one of the resource block in the second set.

24. The method of claim 23, wherein said minimum predetermined bandwidth threshold is the same for all mobile devices served by a base station.

25. The method of claim 24, wherein said minimum predetermined bandwidth threshold is signaled in a broadcast message.

26. The method of claim 23, wherein the predetermined set of resource blocks are signaled in a broadcast message, and

mobile devices are configured to transmit on at least one of the resource blocks in the set based on RRC configuration or (e)PDCCH signaling.

27. The method of claim 23, wherein the predetermined set of resource blocks are signaled in a unicast message, and

mobile devices are configured to transmit on at least one of the resource blocks in the set based on (e)PDCCH signaling.

28. The method of claim 23, wherein each of the at least one resource block is assigned to one of a PUSCH, PUCCH, or PRACH.

29. The method of claim 23, wherein the predetermined set of resource blocks for at least the second resource block is multiplexed between a plurality of mobile devices.

30. The method of claim 23, wherein the multiplexing between a plurality of mobile devices is based on code division multiple access.

31. An apparatus comprising:

means for determining a uplink resource block configuration comprising at least a first set of dynamically scheduled resource blocks and at least a second resource block over a predetermined set of resource blocks on the edge of the channel bandwidth, the resource block configuration occupying at least a minimum predetermined bandwidth threshold; and

means for sending a transmission in the at least one of the resource block in the first set and one of the resource block in the second set.

32. An apparatus comprising:

at least one processor configured for determining a uplink resource block configuration comprising at least a first set of dynamically scheduled resource blocks and at least a second resource block over a predetermined set of resource blocks on the edge of the channel bandwidth, the resource block configuration occupying at least a minimum predetermined bandwidth threshold;

a transceiver configured for sending a transmission in the at least one of the resource block in the first set and one of the resource block in the second set; and

a memory coupled to the at least one processor for storing data.

33. A computer program product comprising:

computer-readable medium storing code for causing at least one computer to;

determine a uplink resource block configuration comprising at least a first set of dynamically scheduled resource blocks and at least a second resource block over a predetermined set of resource blocks on the edge of the channel bandwidth, the resource block configuration occupying at least a minimum predetermined bandwidth threshold; and

send a transmission in the at least one of the resource block in the first set and one of the resource block in the second set.

34. A method for wireless communication operable by a mobile device, the method comprising:

determining a plurality of channel utilization resource blocks assigned to a plurality of mobile devices, the assigned determined by time division multiplexing;

performing a first clear channel assessment (CCA), wherein the CCA occasion occupies a fraction of an OFDM symbol duration;

if CCA is successful, broadcasting an indication for channel utilization as a channel use beacon signal (CUBS) based on the determination, wherein the CUBS transmission is aligned to a predetermined OFDM symbol boundary;

if receiving a grant for transmission on non-contiguous transmission, performing at least a second CCA before each non-contiguous transmission; and

if the second CCA is successful, transmitting the scheduled transmission without transmitting CUBS.

35. The method in claim 34, wherein the first CCA occasion one of multiple successive occasions and the assigned CCA occasion is based on a group membership.

36. The method in claim 35, wherein the group membership is PLMN.

37. The method in claim 34, wherein the second CCA occasion is a single occasion.

38. An apparatus comprising:

means for determining a plurality of channel utilization resource blocks assigned to a plurality of mobile devices, the assigned determined by time division multiplexing;

means for performing a first clear channel assessment (CCA), wherein the CCA occasion occupies a fraction of an OFDM symbol duration;

means for broadcasting, if CCA is successful, an indication for channel utilization as a channel use beacon signal (CUBS) based on the determination, wherein the CUBS transmission are aligned to a predetermined OFDM symbol boundary;

means for performing at least a second CCA before each non-contiguous transmission if receiving a grant for transmission on non-contiguous transmission; and

means for transmitting the scheduled transmission without transmitting CUBS if the second CCA is successful.

39. An apparatus comprising:

at least one processor configured for;

determining a plurality of channel utilization resource blocks assigned to a plurality of mobile devices, the assigned determined by time division multiplexing;

performing a first clear channel assessment (CCA), wherein the CCA occasion occupies a fraction of an OFDM symbol duration;

a transceiver configured for;

broadcasting, if CCA is successful, an indication for channel utilization as a channel use beacon signal (CUBS) based on the determination, wherein the CUBS transmission are aligned to a predetermined OFDM symbol boundary;

performing at least a second CCA before each non-contiguous transmission if receiving a grant for transmission on non-contiguous transmission; and

transmitting the scheduled transmission without transmitting CUBS if the second CCA is successful; and

a memory coupled to the at least one processor for storing data.

40. A computer program product comprising:

computer-readable medium storing code for causing at least one computer to;

determine a plurality of channel utilization resource blocks assigned to a plurality of mobile devices, the assigned determined by time division multiplexing;

perform a first clear channel assessment (CCA), wherein the CCA occasion occupies a fraction of an OFDM symbol duration;

broadcast, if CCA is successful, an indication for channel utilization as a channel use beacon signal (CUBS) based on the determination, wherein the CUBS transmission are aligned to a predetermined OFDM symbol boundary;

perform at least a second CCA before each non-contiguous transmission if receiving a grant for transmission on non-contiguous transmission; and

transmit the scheduled transmission without transmitting CUBS if the second CCA is successful.

41. A method of wireless communication, comprising:

selecting, by a base station, one or more downlink subframes for transmission of a joint control channel for variable transmission time interval (TTI) transmission over multiple uplink subframes in an unlicensed carrier;

setting, by the base station, a size of the joint control channel;

selecting, by the base station, an aggregation level for association with the joint control channel; and

transmitting, by the base station, the joint control channel over the one or more selected downlink subframes.

42. The method of claim 41, wherein the selecting includes:

selecting beginning on a first downlink subframe at least four subframes prior to a first scheduled uplink subframe associated with the variable TTI transmission.

43. The method of claim 41, wherein the selected one or more downlink subframes is one of:

cell-specific or UE-specific.

44. The method of claim 43, wherein the joint control channel is cell-specific, the method further comprising:

adding an uplink grant in the joint control channel associated with each UE located in a cell served by the base station.

45. The method of claim 43, wherein the joint control channel is UE-specific, the method further comprising:

assigning one of the one or more selected downlink subframes to a specific UE for an uplink grant associated with the specific UE.

46. The method of claim 41, wherein the size is a fixed control size that assumes all available uplink subframes are scheduled for uplink transmission.

47. The method of claim 41, wherein the size includes two or more control sizes selected according to one or more available uplink subframes for the variable TTI transmission.

48. The method of claim 41, wherein the selecting the aggregation level includes:

selecting the aggregation level from a plurality of aggregation levels as a function of available uplink subframes for the variable TTI transmission.

49. The method of claim 41, further comprising:

selecting a resource set size for a downlink control channel as a function of available uplink subframes for the variable TTI transmission.

50. The method of claim 41, further comprising:

generating, at the base station, an individual control channel with additional control information for a user equipment (UE) of a plurality of UEs having control information contained within the joint control channel; and

transmitting the individual control channel to the UE, wherein the additional control information contained within the individual control channel supersedes control information for the UE contained in the joint control channel.

51. The method of claim 41, further comprising:

indicating, by the base station, in the joint control channel for a user equipment (UE) to transmit a same transport block over each of the multiple uplink subframes designated for the variable TTI transmission.

52. The method of claim 51, wherein the same transport block includes one or more of:

uplink control signals and uplink data signals.

53. An apparatus configured for wireless communication, comprising:

means for selecting, by a base station, one or more downlink subframes for transmission of a joint control channel for variable transmission time interval (TTI) transmission over multiple uplink subframes in an unlicensed carrier;

means for setting, by the base station, a size of the joint control channel;

means for selecting, by the base station, an aggregation level for association with the joint control channel; and

means for transmitting, by the base station, the joint control channel over the one or more selected downlink subframes.

54. A computer program product for wireless communications in a wireless network, comprising:

a non-transitory computer-readable medium having program code recorded thereon, the program code including;

program code for causing a computer to select, by a base station, one or more downlink subframes for transmission of a joint control channel for variable transmission time interval (TTI) transmission over multiple uplink subframes in an unlicensed carrier;

program code for causing the computer to set, by the base station, a size of the joint control channel;

program code for causing the computer to select, by the base station, an aggregation level for association with the joint control channel; and

program code for causing the computer to transmit, by the base station, the joint control channel over the one or more selected downlink subframes.

55. An apparatus configured for wireless communication, the apparatus comprising:

at least one processor; and

a memory coupled to the at least one processor,

wherein the at least one processor is configured;

to select, by a base station, one or more downlink subframes for transmission of a joint control channel for variable transmission time interval (TTI) transmission over multiple uplink subframes in an unlicensed carrier;

to set, by the base station, a size of the joint control channel;

to select, by the base station, an aggregation level for association with the joint control channel; and

to transmit, by the base station, the joint control channel over the one or more selected downlink subframes.

56. A method of wireless communication, comprising:

receiving, by a user equipment (UE) from a base station over one or more downlink subframes, a joint control channel for variable transmission time interval (TTI) transmission over multiple uplink subframes in an unlicensed carrier; and

transmitting, by the UE the variable TTI transmission over the multiple uplink subframes according to the joint control channel.

57. The method of claim 56, wherein the one or more downlink subframes begin on a first downlink subframe at least four subframes prior to a first scheduled uplink subframe associated with the variable TTI transmission.

58. The method of claim 56, further comprising:

monitoring the joint control channel over the one or more downlink subframes for uplink grants identified for the UE.

59. The method of claim 56, further comprising:

monitoring one or more of the one or more downlink subframes identified for the UE for the joint control channel having uplink grants directed to the UE.

60. The method of claim 56, wherein a size of the joint control channel is a fixed control size that assumes all available uplink subframes are scheduled for uplink transmission.

61. The method of claim 56, wherein the size of the joint control channel includes one of two or more control sizes selected according to one or more available uplink subframes for the variable TTI transmission.

62. The method of claim 56, further comprising:

mapping control information from the joint control channel using an aggregation level received from the base station, wherein the aggregation level is one of a plurality of aggregation levels selected as a function of available uplink subframes for the variable TTI transmission.

63. The method of claim 56, further comprising:

receiving a resource set size indication for a downlink control channel, wherein the resource set size is a function of available uplink subframes for the variable TTI transmission.

64. The method of claim 56, further comprising:

receiving, at the UE from the base station, an individual control channel with additional control information for the UE, wherein the UE has previous control information contained within the joint control channel, and wherein the additional control information contained within the individual control channel supersedes the previous control information contained in the joint control channel.

65. The method of claim 64, wherein the joint control channel is not successfully received by the UE, the method further comprising, in response to receiving the individual control channel when the joint control channel is not successfully received, one of:

declaring an error event;

or

beginning uplink transmission of an uplink signal when a successful clear channel access (CCA) is detected by the UE.

66. The method of claim 65, wherein the uplink signal is a channel use beacon signal (CUBS).

67. The method of claim 56, wherein the joint control channel is associated with an indication for the UE to transmit a same transport block over each of the multiple uplink subframes designated for the variable TTI transmission.

68. The method of claim 67, wherein the same transport block includes one or more of:

uplink control signals and uplink data signals.

69. An apparatus configured for wireless communication, comprising:

means for receiving, by a user equipment (UE) from a base station over one or more downlink subframes, a joint control channel for variable transmission time interval (TTI) transmission over multiple uplink subframes in an unlicensed carrier; and

means for transmitting, by the UE the variable TTI transmission over the multiple uplink subframes according to the joint control channel.

70. A computer program product for wireless communications in a wireless network, comprising:

a non-transitory computer-readable medium having program code recorded thereon, the program code including;

program code for causing a computer to receive, by a user equipment (UE) from a base station over one or more downlink subframes, a joint control channel for variable transmission time interval (TTI) transmission over multiple uplink subframes in an unlicensed carrier; and

program code for causing the computer to transmit, by the UE the variable TTI transmission over the multiple uplink subframes according to the joint control channel.

71. An apparatus configured for wireless communication, the apparatus comprising:

at least one processor; and

a memory coupled to the at least one processor,

wherein the at least one processor is configured;

to receive, by a user equipment (UE) from a base station over one or more downlink subframes, a joint control channel for variable transmission time interval (TTI) transmission over multiple uplink subframes in an unlicensed carrier; and

to transmit, by the UE the variable TTI transmission over the multiple uplink subframes according to the joint control channel.

72. A method of wireless communications, comprising:

preparing, by a base station, control information indicating a transmission grant to one or more user equipments (UEs) for variable transmission time interval (TTI) transmission over a plurality of uplink subframes in an unlicensed carrier, wherein the preparing includes;

providing a cross-carrier scheduling indicator identifying one or more uplink component carriers to which the transmission grant applies, wherein the cross-carrier scheduling indicator applies across each of the plurality of uplink subframes;

providing a resource allocation for the transmission grant;

providing a modulation and coding scheme and redundancy version for each of the plurality of uplink subframes;

providing a new data indicator for each of the plurality of uplink subframes scheduled for new uplink transmissions;

providing a transmission power control signal for the variable TTI transmission;

providing phase information to maintain orthogonality between layers in the variable TTI transmission;

providing downlink assignment indications identifying a number of expected acknowledgments from the base station; and

providing one or more channel state requests and one or more sounding reference signal; and

transmitting, by the base station, the control information to the one or more UEs.

73. The method of claim 72, wherein the resource allocation applies to one of:

each of the plurality of uplink subframes, or an associated subframe of the plurality of uplink subframes, wherein additional resource allocations apply to others of the plurality of uplink subframes.

74. The method of claim 72, wherein the resource allocation provides allocation of larger sized resources in later subframes of the plurality of uplink subframes than the resources allocated in earlier subframes of the plurality of uplink subframes.

75. The method of claim 72, wherein the resource allocation indicates hopping across subframes of the plurality of uplink subframes.

76. The method of claim 72, wherein the transmission power control signal indicates one of:

a single power command for the plurality of uplink subframes or a plurality of power commands in which the power command designated in each of the plurality of power commands corresponds to an associated subframe of the plurality of uplink subframes.

77. The method of claim 72, wherein the phase information applies across one of:

the plurality of uplink subframes, or an associated subframe of the plurality of uplink subframes.

78. The method of claim 72, wherein the one or more channel state requests and one or more sounding reference signal requests identify requested transmission of the channel state information and sounding reference signal one of:

in a first uplink subframe of the plurality of uplink subframes, in each of the plurality of uplink subframes, in an associated subframe of the plurality of uplink subframes.

79. An apparatus configured for wireless communications, comprising:

means for preparing, by a base station, control information indicating a transmission grant to one or more user equipments (UEs) for variable transmission time interval (TTI) transmission over a plurality of uplink subframes in an unlicensed carrier, wherein the means for preparing includes;

means for providing a cross-carrier scheduling indicator identifying one or more uplink component carriers to which the transmission grant applies, wherein the cross-carrier scheduling indicator applies across each of the plurality of uplink subframes;

means for providing a resource allocation for the transmission grant;

means for providing a modulation and coding scheme and redundancy version for each of the plurality of uplink subframes;

means for providing a new data indicator for each of the plurality of uplink subframes scheduled for new uplink transmissions;

means for providing a transmission power control signal for the variable TTI transmission;

means for providing phase information to maintain orthogonality between layers in the variable TTI transmission;

means for providing downlink assignment indications identifying a number of expected acknowledgments from the base station; and

means for providing one or more channel state requests and one or more sounding reference signal; and

means for transmitting, by the base station, the control information to the one or more UEs.

80. A computer program product for wireless communications in a wireless network, comprising:

a non-transitory computer-readable medium having program code recorded thereon, the program code including;

program code for causing a computer to prepare, by a base station, control information indicating a transmission grant to one or more user equipments (UEs) for variable transmission time interval (TTI) transmission over a plurality of uplink subframes in an unlicensed carrier, wherein the program code for causing the computer to prepare includes program code for causing the computer to;

provide a cross-carrier scheduling indicator identifying one or more uplink component carriers to which the transmission grant applies, wherein the cross-carrier scheduling indicator applies across each of the plurality of uplink subframes;

provide a resource allocation for the transmission grant;

provide a modulation and coding scheme and redundancy version for each of the plurality of uplink subframes;

provide a new data indicator for each of the plurality of uplink subframes scheduled for new uplink transmissions;

provide a transmission power control signal for the variable TTI transmission;

provide phase information to maintain orthogonality between layers in the variable TTI transmission;

provide downlink assignment indications identifying a number of expected acknowledgments from the base station; and

provide one or more channel state requests and one or more sounding reference signal; and

program code for causing the computer to transmit, by the base station, the control information to the one or more UEs.

81. An apparatus configured for wireless communication, the apparatus comprising:

at least one processor; and

a memory coupled to the at least one processor,

wherein the at least one processor is configured;

to prepare, by a base station, control information indicating a transmission grant to one or more user equipments (UEs) for variable transmission time interval (TTI) transmission over a plurality of uplink subframes in an unlicensed carrier, wherein the program code for causing the computer to prepare includes program code for causing the computer to;

provide a cross-carrier scheduling indicator identifying one or more uplink component carriers to which the transmission grant applies, wherein the cross-carrier scheduling indicator applies across each of the plurality of uplink subframes;

provide a resource allocation for the transmission grant;

provide a modulation and coding scheme and redundancy version for each of the plurality of uplink subframes;

provide a new data indicator for each of the plurality of uplink subframes scheduled for new uplink transmissions;

provide a transmission power control signal for the variable TTI transmission;

provide phase information to maintain orthogonality between layers in the variable TTI transmission;

provide downlink assignment indications identifying a number of expected acknowledgments from the base station; and

provide one or more channel state requests and one or more sounding reference signal; and

to transmit, by the base station, the control information to the one or more UEs.

82. A method of wireless communications, comprising:

receiving, by a user equipment (UE), control information indicating a transmission grant from a base station for variable transmission time interval (TTI) transmission over a plurality of uplink subframes in an unlicensed carrier;

preparing, by the UE, for the variable TTI transmission using the control information, wherein the control information includes;

a cross-carrier scheduling indicator identifying one or more uplink component carriers to which the transmission grant applies, wherein the cross-carrier scheduling indicator applies across each of the plurality of uplink subframes;

a resource allocation for the transmission grant;

a modulation and coding scheme and redundancy version for each of the plurality of uplink subframes;

a new data indicator for each of the plurality of uplink subframes scheduled for new uplink transmissions;

a transmission power control signal for the variable TTI transmission;

phase information to maintain orthogonality between layers in the variable TTI transmission;

downlink assignment indications identifying a number of expected acknowledgments from the base station; and

one or more channel state requests and one or more sounding reference signal; and

transmitting, by the UE, the variable TTI transmissions over the plurality of uplink subframes according to the control information.

83. The method of claim 82, wherein the resource allocation applies to one of:

each of the plurality of uplink subframes, or an associated subframe of the plurality of uplink subframes, wherein additional resource allocations apply to others of the plurality of uplink subframes.

84. The method of claim 82, wherein the resource allocation provides allocation of larger sized resources in later subframes of the plurality of uplink subframes than the resources allocated in earlier subframes of the plurality of uplink subframes.

85. The method of claim 82, wherein the resource allocation indicates hopping across subframes of the plurality of uplink subframes.

86. The method of claim 82, wherein the transmission power control signal indicates one of:

a single power command for the plurality of uplink subframes or a plurality of power commands in which the power command designated in each of the plurality of power commands corresponds to an associated subframe of the plurality of uplink subframes.

87. The method of claim 82, wherein the phase information applies across one of:

the plurality of uplink subframes, or an associated subframe of the plurality of uplink subframes.

88. The method of claim 82, wherein the one or more channel state requests and one or more sounding reference signal requests identify requested transmission of the channel state information and sounding reference signal one of:

in a first uplink subframe of the plurality of uplink subframes, in each of the plurality of uplink subframes, in an associated subframe of the plurality of uplink subframes.

89. The method of claim 88, further comprising:

transmitting, by the UE, a physical uplink channel for a duration of a subframe when the one or more sounding reference signal requests indicate no sounding reference signal is to be transmitted in one of the plurality of uplink subframes.

90. An apparatus configured for wireless communications, comprising:

means for receiving, by a user equipment (UE), control information indicating a transmission grant from a base station for variable transmission time interval (TTI) transmission over a plurality of uplink subframes in an unlicensed carrier;

means for preparing, by the UE, for the variable TTI transmission using the control information, wherein the control information includes;

a cross-carrier scheduling indicator identifying one or more uplink component carriers to which the transmission grant applies, wherein the cross-carrier scheduling indicator applies across each of the plurality of uplink subframes;

a resource allocation for the transmission grant;

a modulation and coding scheme and redundancy version for each of the plurality of uplink subframes;

a new data indicator for each of the plurality of uplink subframes scheduled for new uplink transmissions;

a transmission power control signal for the variable TTI transmission;

phase information to maintain orthogonality between layers in the variable TTI transmission;

downlink assignment indications identifying a number of expected acknowledgments from the base station; and

one or more channel state requests and one or more sounding reference signal; and

means for transmitting, by the UE, the variable TTI transmissions over the plurality of uplink subframes according to the control information.

91. A computer program product for wireless communications in a wireless network, comprising:

a non-transitory computer-readable medium having program code recorded thereon, the program code including;

program code for causing a computer to receive, by a user equipment (UE), control information indicating a transmission grant from a base station for variable transmission time interval (TTI) transmission over a plurality of uplink subframes in an unlicensed carrier;

program code for causing the computer to prepare, by the UE, for the variable TTI transmission using the control information, wherein the control information includes;

a cross-carrier scheduling indicator identifying one or more uplink component carriers to which the transmission grant applies, wherein the cross-carrier scheduling indicator applies across each of the plurality of uplink subframes;

a resource allocation for the transmission grant;

a modulation and coding scheme and redundancy version for each of the plurality of uplink subframes;

a new data indicator for each of the plurality of uplink subframes scheduled for new uplink transmissions;

a transmission power control signal for the variable TTI transmission;

phase information to maintain orthogonality between layers in the variable TTI transmission;

downlink assignment indications identifying a number of expected acknowledgments from the base station; and

one or more channel state requests and one or more sounding reference signal; and

program code for causing the computer to transmit, by the UE, the variable TTI transmissions over the plurality of uplink subframes according to the control information.

92. An apparatus configured for wireless communication, the apparatus comprising:

at least one processor; and

a memory coupled to the at least one processor,

wherein the at least one processor is configured;

to receive, by a user equipment (UE), control information indicating a transmission grant from a base station for variable transmission time interval (TTI) transmission over a plurality of uplink subframes in an unlicensed carrier;

to prepare, by the UE, for the variable TTI transmission using the control information, wherein the control information includes;

a cross-carrier scheduling indicator identifying one or more uplink component carriers to which the transmission grant applies, wherein the cross-carrier scheduling indicator applies across each of the plurality of uplink subframes;

a resource allocation for the transmission grant;

a modulation and coding scheme and redundancy version for each of the plurality of uplink subframes;

a new data indicator for each of the plurality of uplink subframes scheduled for new uplink transmissions;

a transmission power control signal for the variable TTI transmission;

phase information to maintain orthogonality between layers in the variable TTI transmission;

downlink assignment indications identifying a number of expected acknowledgments from the base station; and

one or more channel state requests and one or more sounding reference signal; and

to transmit, by the UE, the variable TTI transmissions over the plurality of uplink subframes according to the control information.