CONCURRENT WIRELESS COMMUNICATIONS OVER LICENSED AND UNLICENSED SPECTRUM

• US 20140341024A1
• Filed: 05/19/2014
• Published: 11/20/2014
• Est. Priority Date: 05/20/2013
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Bhushan, Naga, Malladi, Durga Prasad, Wei, Yongbin, Gaal, Peter, Luo, Tao, Ji, Tingfang, Horn, Gavin Bernard, Chen, Wanshi, Damnjanovic, Aleksandar
• Granted Patent: US 9,473,981 B2
• Time in Patent Office: Days
• US Class Current: 370/230.1
• CPC Class Codes: H04J 11/00 Orthogonal multiplex systems, e.g. using WALSH codesH04J13/00 takes precedence
• CPC Class Codes: H04L 1/00 Arrangements for detecting or preventing errors in the information received correcting synchronisation H04L7/00
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/003 Adaptive formatting arrangements particular to signalling, e.g. variable amount of bits
• CPC Class Codes: H04L 1/009 arrangements specific to transmitters
• CPC Class Codes: H04L 1/0612 Space-time modulation
• CPC Class Codes: H04L 27/0006 Assessment of spectral gaps suitable for allocating digitally modulated signals, e.g. for carrier allocation in cognitive radio for spectrum sharing between different networks H04W16/14
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04L 27/2603 Signal structure ensuring backward compatibility with legacy system
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0044 allocation of payload
• CPC Class Codes: H04L 5/005 of common pilots, i.e. pilots destined for multiple users or terminals
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/14 Two-way operation using the same type of signal, i.e. duplex
• CPC Class Codes: H04L 5/1469 using time-sharing
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 28/0252 per individual bearer or channel dynamic wireless traffic scheduling H04W72/12
• CPC Class Codes: H04W 28/0289 : Congestion control load shedding arrangements in network planning H04W16/08; performing reselection for handling the traffic H04W36/22; wireless traffic scheduling H04W72/12
• CPC Class Codes: H04W 28/08 : Load balancing or load distribution transferring a connection for handling the traffic H04W36/22; wireless traffic scheduling H04W72/12
• CPC Class Codes: H04W 28/16 : Central resource management; Negotiation of resources or communication parameters, e.g. negotiating bandwidth or QoS [Quality of Service]
• CPC Class Codes: H04W 48/10 : using broadcasted information
• CPC Class Codes: H04W 56/001 : Synchronization between nodes
• CPC Class Codes: H04W 56/0015 : one node acting as a reference for the others
• CPC Class Codes: H04W 56/002 : Mutual synchronization
• CPC Class Codes: H04W 72/04 : Wireless resource allocation
• CPC Class Codes: H04W 72/12 : Wireless traffic scheduling
• CPC Class Codes: H04W 72/21 : in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 72/541 : using the level of interference
• CPC Class Codes: H04W 74/006 : in the downlink, i.e. towards the terminal
• CPC Class Codes: H04W 74/04 : Scheduled access hybrid access H04W74/02
• CPC Class Codes: H04W 74/0808 : using carrier sensing, e.g. carrier sense multiple access [CSMA]
• CPC Class Codes: H04W 74/0816 : with collision avoidance
• CPC Class Codes: H04W 74/0833 : Random access procedures, e.g. with 4-step access
• CPC Class Codes: H04W 76/15 : Setup of multiple wireless link connections
• CPC Class Codes: H04W 84/12 : WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/02 : Terminal devices
• CPC Class Codes: H04W 88/06 : adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals
• CPC Class Codes: H04W 88/08 : Access point devices

Abstract

Methods and apparatuses are described for wireless communications. A first method includes transmitting a first Orthogonal Frequency-Division Multiple Access (OFDMA) communications signal to a wireless node in a licensed spectrum, and transmitting, concurrently with the transmission of the first OFDMA communications signal, a second OFDMA communications signal to the wireless node in an unlicensed spectrum. A second method includes receiving a first Orthogonal Frequency-Division Multiple Access (OFDMA) communications signal from a wireless node in a licensed spectrum, and receiving, concurrently with the reception of the first OFDMA communications signal, a second OFDMA communication signal from the wireless node in an unlicensed spectrum. A third method includes generating a periodic gating interval for a cellular downlink in an unlicensed spectrum, and synchronizing at least one boundary of the periodic gating interval with at least one boundary of a periodic frame structure associated with a primary component carrier of the cellular downlink.

Claims

1. A method for wireless communications, comprising:

transmitting a first Orthogonal Frequency-Division Multiple Access (OFDMA) communications signal to a wireless node in a licensed spectrum; and

transmitting, concurrently with the transmission of the first OFDMA communications signal, a second OFDMA communications signal to the wireless node in an unlicensed spectrum.

2. The method of claim 1, wherein the transmission of the second OFDMA communications signal in the unlicensed spectrum is time-synchronized with the first OFDMA communications signal in the licensed spectrum, with a fixed offset between a frame structure of the first OFDMA communications signal and a frame structure of the second OFDMA communications signal.

3. The method of claim 2, wherein the fixed offset is equal to zero.

4. The method of claim 1, further comprising:

receiving, concurrently with the transmission of the first and second OFDMA communications signals, a first Single-Carrier Frequency-Division Multiple Access (SC-FDMA) communications signal from the wireless node in the licensed spectrum.

5. The method of claim 4, further comprising:

receiving, concurrently with the transmission of the first and second OFDMA communications signals, a second SC-FDMA communications signal from the wireless node in the unlicensed spectrum.

6. The method of claim 4, wherein the first SC-FDMA communications signal received from the wireless node in the licensed spectrum carries signaling or other control information related to the second OFDMA communications signal transmitted in the unlicensed spectrum.

7. The method of claim 6, further comprising:

receiving, concurrently with the transmission of the first and second OFDMA communications signals, a second SC-FDMA communications signal from the wireless node in the unlicensed spectrum.

8. The method of claim 1, further comprising:

receiving, concurrently with the transmission of the first and second OFDMA communications signals, a first SC-FDMA communications signal from the wireless node in the licensed spectrum and a second SC-FDMA communications signal from the wireless node in the unlicensed spectrum.

9. The method of claim 1, wherein the wireless node comprises a user equipment (UE).

10. The method of claim 1, wherein the first and second OFDMA communications signals are transmitted from an evolved Node B (eNB).

11. The method of claim 1, wherein each of the first and second OFDMA communications signals comprises a Long Term Evolution (LTE) signal.

12. An apparatus for wireless communications, comprising:

means for transmitting a first Orthogonal Frequency-Division Multiple Access (OFDMA) communications signal to a wireless node in a licensed spectrum; and

means for transmitting, concurrently with the transmission of the first OFDMA communications signal, a second OFDMA communications signal to the wireless node in an unlicensed spectrum.

13. The apparatus of claim 12, wherein the transmission of the second OFDMA communications signal in the unlicensed spectrum is time-synchronized with the first OFDMA communications signal in the licensed spectrum, with a fixed offset between a frame structure of the first OFDMA communications signal and a frame structure of the second OFDMA communications signal.

14. The apparatus of claim 13, wherein the fixed offset is equal to zero.

15. The apparatus of claim 12, further comprising:

means for receiving, concurrently with the transmission of the first and second OFDMA communications signals, a first Single-Carrier Frequency-Division Multiple Access (SC-FDMA) communications signal from the wireless node in the licensed spectrum.

16. The apparatus of claim 15, further comprising:

means for receiving, concurrently with the transmission of the first and second OFDMA communications signals, a second SC-FDMA communications signal from the wireless node in the unlicensed spectrum.

17. The apparatus of claim 15, wherein the first SC-FDMA communications signal received from the wireless node in the licensed spectrum carries signaling or other control information related to the second OFDMA communications signal transmitted in the unlicensed spectrum.

18. The apparatus of claim 17, further comprising:

means for receiving, concurrently with the transmission of the first and second OFDMA communications signals, a second SC-FDMA communications signal from the wireless node in the unlicensed spectrum.

19. The apparatus of claim 12, further comprising:

means for receiving, concurrently with the transmission of the first and second OFDMA communications signals, a first SC-FDMA communications signal from the wireless node in the licensed spectrum and a second SC-FDMA communications signal from the wireless node in the unlicensed spectrum.

20. The apparatus of claim 12, wherein the wireless node comprises a user equipment (UE).

21. The apparatus of claim 12, wherein the first and second OFDMA communications signals are transmitted from an evolved Node B (eNB).

22. The apparatus of claim 12, wherein each of the first and second OFDMA communications signals comprises a Long Term Evolution (LTE) signal.

23. An apparatus for wireless communications, comprising:

a processor;

memory in electronic communication with the processor; and

instructions stored in the memory, the instructions being executable by the processor to;

transmit a first Orthogonal Frequency-Division Multiple Access (OFDMA) communications signal to a wireless node in a licensed spectrum; and

transmit, concurrently with the transmission of the first OFDMA communications signal, a second OFDMA communications signal to the wireless node in an unlicensed spectrum.

24. The apparatus of claim 23, wherein the transmission of the second OFDMA communications signal in the unlicensed spectrum is time-synchronized with the first OFDMA communications signal in the licensed spectrum, with a fixed offset between a frame structure of the first OFDMA communications signal and a frame structure of the second OFDMA communications signal.

25. The apparatus of claim 24, wherein the fixed offset is equal to zero.

26. The apparatus of claim 23, wherein the instructions are executable by the processor to:

receive, concurrently with the transmission of the first and second OFDMA communications signals, a first Single-Carrier Frequency-Division Multiple Access (SC-FDMA) communications signal from the wireless node in the licensed spectrum.

27. The apparatus of claim 26, wherein the instructions are executable by the processor to:

receive, concurrently with the transmission of the first and second OFDMA communications signals, a second SC-FDMA communications signal from the wireless node in the unlicensed spectrum.

28. The apparatus of claim 26, wherein the first SC-FDMA communications signal received from the wireless node in the licensed spectrum carries signaling or other control information related to the second OFDMA communications signal transmitted in the unlicensed spectrum.

29. The apparatus of claim 28, wherein the instructions are executable by the processor to:

receive, concurrently with the transmission of the first and second OFDMA communications signals, a second SC-FDMA communications signal from the wireless node in the unlicensed spectrum.

30. The apparatus of claim 23, wherein the instructions are executable by the processor to:

receive, concurrently with the transmission of the first and second OFDMA communications signals, a first SC-FDMA communications signal from the wireless node in the licensed spectrum and a second SC-FDMA communications signal from the wireless node in the unlicensed spectrum.

31. The apparatus of claim 23, wherein the wireless node comprises a user equipment (UE).

32. The apparatus of claim 23, wherein the first and second OFDMA communications signals are transmitted from an evolved Node B (eNB).

33. The apparatus of claim 23, wherein each of the first and second OFDMA communications signals comprises a Long Term Evolution (LTE) signal.

34. A computer program product for communications by a wireless communications apparatus in a wireless communications system, the computer program product comprising a non-transitory computer-readable medium storing instructions executable by a processor to cause the wireless communications apparatus to:

transmit a first Orthogonal Frequency-Division Multiple Access (OFDMA) communications signal to a wireless node in a licensed spectrum; and

transmit, concurrently with the transmission of the first OFDMA communications signal, a second OFDMA communications signal to the wireless node in an unlicensed spectrum.

35. The computer program product of claim 34, wherein the transmission of the second OFDMA communications signal in the unlicensed spectrum is time-synchronized with the first OFDMA communications signal in the licensed spectrum, with a fixed offset between a frame structure of the first OFDMA communications signal and a frame structure of the second OFDMA communications signal.

36. The computer program product of claim 35, wherein the fixed offset is equal to zero.

37. The computer program product of claim 34, wherein the instructions are executable by the processor to cause the wireless communications apparatus to:

receive, concurrently with the transmission of the first and second OFDMA communications signals, a first SC-FDMA communications signal from the wireless node in the licensed spectrum and a second SC-FDMA communications signal from the wireless node in the unlicensed spectrum.

38. The computer program product of claim 34, wherein the wireless node comprises a user equipment (UE).

39. A method for wireless communications, comprising:

receiving a first SC-FDMA communications signal from a wireless node in a licensed spectrum; and

receiving, concurrently with the reception of the first SC-FDMA communications signal, a second SC-FDMA signal from the wireless node in an unlicensed spectrum.

40. The method of claim 39, wherein the wireless node comprises a user equipment (UE).

41. The method of claim 39, wherein the first and second SC-FDMA communications signals are received at an evolved Node B (eNB).

42. The method of claim Error! Reference source not found., wherein each of the first and second SC-FDMA communications signals comprises a Long Term Evolution (LTE) signal.

43. An apparatus for wireless communications, comprising:

means for receiving a first SC-FDMA communications signal from a wireless node in a licensed spectrum; and

means for receiving, concurrently with the reception of the first SC-FDMA communications signal, a second SC-FDMA signal from the wireless node in an unlicensed spectrum.

44. The apparatus of claim 43, wherein the wireless node comprises a user equipment (UE).

45. The method of claim 43, wherein the first and second SC-FDMA communications signals are received at an evolved Node B (eNB).

46. The apparatus of claim 43, wherein each of the first and second SC-FDMA communications signals comprises a Long Term Evolution (LTE) signal.

47. An apparatus for wireless communications, comprising:

a processor;

memory in electronic communication with the processor; and

instructions stored in the memory, the instructions being executable by the processor to;

receive a first SC-FDMA communications signal from a wireless node in a licensed spectrum; and

receive, concurrently with the reception of the first SC-FDMA communications signal, a second SC-FDMA signal from the wireless node in an unlicensed spectrum.

48. The apparatus of claim 47, wherein the wireless node comprises a user equipment (UE).

49. The apparatus of claim 47, wherein the first and second SC-FDMA communications signals are received at an evolved Node B (eNB).

50. The apparatus of claim 47, wherein each of the first and second SC-FDMA communications signals comprises a Long Term Evolution (LTE) signal.

51. A computer program product for communications by a wireless communications apparatus in a wireless communications system, the computer program product comprising a non-transitory computer-readable medium storing instructions executable by a processor to cause the wireless communications apparatus to:

receive a first SC-FDMA communications signal from a wireless node in a licensed spectrum; and

receive, concurrently with the reception of the first SC-FDMA communications signal, a second SC-FDMA signal from the wireless node in an unlicensed spectrum.

52. The computer program product of claim 51, wherein the wireless node comprises a user equipment (UE).

53. A method for wireless communications, comprising:

receiving a first Orthogonal Frequency-Division Multiple Access (OFDMA) communications signal from a wireless node in a licensed spectrum; and

receiving, concurrently with the reception of the first OFDMA communications signal, a second OFDMA communication signal from the wireless node in an unlicensed spectrum.

54. The method of claim 53, further comprising:

transmitting, concurrently with the reception of the first and second OFDMA communications signals, a first SC-FDMA communications signal to the wireless node in the licensed spectrum.

55. The method of claim 54, further comprising:

transmitting, concurrently with the reception of the first and second OFDMA communications signals, a second SC-FDMA communications signal to the wireless node in the unlicensed spectrum.

56. The method of claim 54, wherein the first SC-FDMA communications signal transmitted to the wireless node in the licensed spectrum carries signaling or other control information related to the second OFDMA signal received in the unlicensed spectrum.

57. The method of claim 56, further comprising:

transmitting, concurrently with the reception of the first and second OFDMA communications signals, a second SC-FDMA communications signal to the wireless node in the unlicensed spectrum.

58. The method of claim 53, further comprising:

transmitting, concurrently with the reception of the first and second OFDMA communications signals, a first SC-FDMA communications signal to the wireless node in the licensed spectrum and a second SC-FDMA communications signal to the wireless node in the unlicensed spectrum.

59. The method of claim 53, wherein the wireless node comprises an evolved Node B (eNB).

60. The method of claim 53, wherein the first and second OFDMA communications signals are received at a user equipment (UE).

61. The method of claim 53, wherein each of the first and second OFDMA communications signals comprises a Long Term Evolution (LTE) signal.

62. An apparatus for wireless communications, comprising:

means for receiving a first Orthogonal Frequency-Division Multiple Access (OFDMA) communications signal from a wireless node in a licensed spectrum; and

means for receiving, concurrently with the reception of the first OFDMA communications signal, a second OFDMA communication signal from the wireless node in an unlicensed spectrum.

63. The apparatus of claim 62, further comprising:

means for transmitting, concurrently with the reception of the first and second OFDMA communications signals, a first SC-FDMA communications signal to the wireless node in a licensed spectrum.

64. The apparatus of claim 63, further comprising:

means for transmitting, concurrently with the reception of the first and second OFDMA communications signals, a second SC-FDMA communications signal to the wireless node in the unlicensed spectrum.

65. The apparatus of claim 63, wherein the first SC-FDMA communications signal transmitted to the wireless node in the licensed spectrum carries signaling or other control information related to the second OFDMA signal received in the unlicensed spectrum.

66. The apparatus of claim 65, further comprising:

means for transmitting, concurrently with the reception of the first and second OFDMA communications signals, a second SC-FDMA communications signal to the wireless node in the unlicensed spectrum.

67. The apparatus of claim 62, further comprising:

means for transmitting, concurrently with the reception of the first and second OFDMA communications signals, a first SC-FDMA communications signal to the wireless node in the licensed spectrum and a second SC-FDMA communications signal to the wireless node in the unlicensed spectrum.

68. The apparatus of claim 62, wherein the wireless node comprises an evolved Node B (eNB).

69. The apparatus of claim 62, wherein the first and second OFDMA communications signals are received at a user equipment (UE).

70. The apparatus of claim 62, wherein each of the first and second OFDMA communications signals comprises LTE signals.

71. An apparatus for wireless communications, comprising:

a processor;

memory in electronic communication with the processor; and

instructions stored in the memory, the instructions being executable by the processor to;

receive a first Orthogonal Frequency-Division Multiple Access (OFDMA) communications signal from a wireless node in a licensed spectrum; and

receive, concurrently with the reception of the first OFDMA communications signal, a second OFDMA communication signal from the wireless node in an unlicensed spectrum.

72. The apparatus of claim 71, wherein the instructions are executable by the processor to:

transmit, concurrently with the reception of the first and second OFDMA communications signals, a first SC-FDMA communications signal to the wireless node in a licensed spectrum.

73. The apparatus of claim 72, wherein the instructions are executable by the processor to:

transmit, concurrently with the reception of the first and second OFDMA communications signals, a second SC-FDMA communications signal to the wireless node in the unlicensed spectrum.

74. The apparatus of claim 72, wherein the first SC-FDMA communications signal transmitted to the wireless node in the licensed spectrum carries signaling or other control information related to the second OFDMA signal received in the unlicensed spectrum.

75. The apparatus of claim 74, wherein the instructions are executable by the processor to:

transmit, concurrently with the reception of the first and second OFDMA communications signals, a second SC-FDMA communications signal to the wireless node in the unlicensed spectrum.

76. The apparatus of claim 71, wherein the instructions are executable by the processor to:

transmit, concurrently with the reception of the first and second OFDMA communications signals, a first SC-FDMA communications signal to the wireless node in the licensed spectrum and a second SC-FDMA communications signal to the wireless node in the unlicensed spectrum.

77. The apparatus of claim 71, wherein the wireless node comprises an evolved Node B (eNB).

78. The apparatus of claim 71, wherein the first and second OFDMA communications signals are received at a user equipment (UE).

79. The apparatus of claim 71, wherein each of the first and second OFDMA communications signals comprises LTE signals.

80. A computer program product for communications by a wireless communications apparatus in a wireless communications system, the computer program product comprising a non-transitory computer-readable medium storing instructions executable by a processor to cause the wireless communications apparatus to:

receive a first Orthogonal Frequency-Division Multiple Access (OFDMA) communications signal from a wireless node in a licensed spectrum; and

receive, concurrently with the reception of the first OFDMA communications signal, a second OFDMA communication signal from the wireless node in an unlicensed spectrum.

81. The computer program product of claim 80, wherein the instructions are executable by the processor to cause the wireless communications apparatus to:

transmit, concurrently with the reception of the first and second OFDMA communications signals, a first SC-FDMA communications signal to the wireless node in a licensed spectrum.

82. The computer program product of claim 81, wherein the instructions are executable by the processor to cause the wireless communications apparatus to:

transmit, concurrently with the reception of the first and second OFDMA communications signals, a second SC-FDMA communications signal to the wireless node in the unlicensed spectrum.

83. The computer program product of claim 80, wherein the wireless node comprises an evolved Node B (eNB).

84. A method for wireless communications, comprising:

transmitting a first SC-FDMA communications signal to a wireless node in a licensed spectrum; and

transmitting, concurrently with the transmission of the first SC-FDMA communications signal, a second SC-FDMA communications signal to the wireless node in an unlicensed spectrum.

85. The method of claim 84, wherein the wireless node comprises an evolved Node B (eNB).

86. The method of claim 84, wherein the first and second OFDMA communications signals are received at a user equipment (UE).

87. The method of claim 84, wherein each of the first and second SC-FDMA communications signals comprises a Long Term Evolution (LTE) signal.

88. An apparatus for wireless communications, comprising:

means for transmitting a first SC-FDMA communications signal to a wireless node in a licensed spectrum; and

means for transmitting, concurrently with the transmission of the first SC-FDMA communications signal, a second SC-FDMA communications signal to the wireless node in an unlicensed spectrum.

89. The apparatus of claim 88, wherein the wireless node comprises an evolved Node B (eNB).

90. The apparatus of claim 88, wherein the first and second SC-FDMA communications signals are transmitted from a user equipment (UE).

91. The apparatus of claim 88, wherein each of the first and second SC-FDMA communications signals comprises a Long Term Evolution (LTE) signal.

92. An apparatus for wireless communications, comprising:

a processor;

memory in electronic communication with the processor; and

instructions stored in the memory, the instructions being executable by the processor to;

transmit a first SC-FDMA communications signal to a wireless node in a licensed spectrum; and

transmit, concurrently with the transmission of the first SC-FDMA communications signal, a second SC-FDMA communications signal to the wireless node in an unlicensed spectrum.

93. The apparatus of claim 92, wherein the wireless node comprises an evolved Node B (eNB).

94. The apparatus of claim 92, wherein the first and second SC-FDMA communications signals are transmitted from a user equipment (UE).

95. The apparatus of claim 92, wherein each of the first and second SC-FDMA communications signals comprises a Long Term Evolution (LTE) signal.

96. A computer program product for communications by a wireless communications apparatus in a wireless communications system, the computer program product comprising a non-transitory computer-readable medium storing instructions executable by a processor to cause the wireless communications apparatus to:

transmit a first SC-FDMA communications signal to a wireless node in a licensed spectrum; and

transmit, concurrently with the transmission of the first SC-FDMA communications signal, a second SC-FDMA communications signal to the wireless node in an unlicensed spectrum.

97. The computer program product of claim 96, wherein the wireless node comprises an evolved Node B (eNB).

98. A method for wireless communications, comprising:

generating a periodic gating interval for a downlink in an unlicensed spectrum; and

synchronizing at least one boundary of the periodic gating interval with at least one boundary of a periodic frame structure associated with a primary component carrier (PCC) of the downlink.

99. The method of claim 98, wherein the PCC comprises a carrier in a licensed spectrum.

100. The method of claim 98, wherein the periodic gating interval comprises a listen-before-talk (LBT) frame and the periodic frame structure comprises a Long Term Evolution (LTE) radio frame.

101. The method of claim 98, wherein a duration of the periodic gating interval is an integral multiple of a duration of the periodic frame structure.

102. The method of claim 98, wherein a duration of the periodic gating interval is a sub-multiple of a duration of the periodic frame structure.

103. The method of claim 98, wherein the downlink carries Long Term Evolution (LTE) signals.

104. An apparatus for wireless communications, comprising:

means for generating a periodic gating interval for a downlink in an unlicensed spectrum; and

means for synchronizing at least one boundary of the periodic gating interval with at least one bounday of a periodic frame structure associated with a primary component carrier (PCC) of the downlink.

105. The apparatus of claim 104, wherein the PCC comprises a carrier in a licensed spectrum.

106. The apparatus of claim 104, wherein the periodic gating interval comprises a listen-before-talk (LBT) frame and the periodic frame structure comprises a Long Term Evolution (LTE) radio frame.

107. The apparatus of claim 104, wherein a duration of the periodic gating interval is an integral multiple of a duration of the periodic frame structure.

108. The apparatus of claim 104, wherein a duration of the periodic gating interval is a sub-multiple of a duration of the periodic frame structure.

109. The apparatus of claim 104, wherein the downlink carries Long Term Evolution (LTE) signals.

110. An apparatus for wireless communications, comprising:

a processor;

memory in electronic communication with the processor; and

instructions stored in the memory, the instructions being executable by the processor to;

generate a periodic gating interval for a downlink in an unlicensed spectrum; and

synchronize at least one boundary of the periodic gating interval with at least one bounday of a periodic frame structure associated with a primary component carrier (PCC) of the cellular downlink.

111. The apparatus of claim 110, wherein the PCC comprises a carrier in a licensed spectrum.

112. The apparatus of claim 110, wherein the periodic gating interval comprises a listen-before-talk (LBT) frame and the periodic frame structure comprises a Long Term Evolution (LTE) radio frame.

113. The apparatus of claim 110, wherein a duration of the periodic gating interval is an integral multiple of a duration of the periodic frame structure.

114. The apparatus of claim 110, wherein a duration of the periodic gating interval is a sub-multiple of a duration of the periodic frame structure.

115. The apparatus of claim 110, wherein the downlink carries Long Term Evolution (LTE) signals.

116. A computer program product for communications by a wireless communications apparatus in a wireless communications system, the computer program product comprising a non-transitory computer-readable medium storing instructions executable by a processor to cause the wireless communications apparatus to:

generate a periodic gating interval for a downlink in an unlicensed spectrum; and

synchronize at least one boundary of the periodic gating interval with at least one bounday of a periodic frame structure associated with a primary component carrier (PCC) of the cellular downlink.

117. The computer program product of claim 116, wherein the PCC comprises a carrier in a licensed spectrum.

118. The computer program product of claim 116, wherein the periodic gating interval comprises a listen-before-talk (LBT) frame and the periodic frame structure comprises a Long Term Evolution (LTE) radio frame.