Techniques for selecting subframe type or for interleaving signals for wireless communications over unlicensed spectrum

• US 9,565,593 B2
• Filed: 05/19/2014
• Issued: 02/07/2017
• 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
• Primary Examiner(s): Mattis, Jason
• Application Number:
  US14/281,636
• Publication Number:
  US 20140341018A1
• Time in Patent Office: 995 Days
• US Class Current: 1/1
• 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 in which an unlicensed spectrum is used for Long Term Evolution (LTE) communications. A first method includes comparing past transmission activity on an unlicensed spectrum to an activity threshold, transmitting a first subframe type in the unlicensed spectrum during a next active transmission when the past transmission activity is greater than the activity threshold, and transmitting a second subframe type in the unlicensed spectrum during a next active transmission when the past transmission activity is lesser than the activity threshold, the second subframe type comprising a more robust subframe type than the first subframe type. A second method includes generating one or both of PUCCH signals and PUSCH signals based on interleaved signals that increase nominal bandwidth occupancy in an unlicensed spectrum, and transmitting the generated signals in the unlicensed spectrum. A third method includes receiving the PUCCH signals and the PUSCH signals.

Claims

1. A method for wireless communications, comprising:

comparing past transmission activity on an unlicensed spectrum to an activity threshold, wherein the activity threshold comprises one or more of;

a number of gated-ON periods in the unlicensed spectrum over a period of time, a duration of a number of gated-ON periods in the unlicensed spectrum over a period of time, and a number of synchronization (SYNC) subframes transmitted in the unlicensed spectrum over a period of time;

transmitting a first subframe type in the unlicensed spectrum during a next active transmission when the past transmission activity is greater than the activity threshold; and

transmitting a second subframe type in the unlicensed spectrum during a next active transmission when the past transmission activity is less than the activity threshold, the second subframe type comprising more pilots than the first subframe type.

2. The method of claim 1, wherein the first subframe type comprises a legacy carrier type (LCT) subframe.

3. The method of claim 1, wherein the first subframe type comprises a new carrier type (NCT) subframe.

4. The method of claim 1, wherein the second subframe type comprises a legacy carrier type (LCT) subframe comprising added common pilots in comparison to the first subframe type, and wherein the added common pilots are used for tracking and channel estimation.

5. The method of claim 1, wherein the second subframe type comprises a new carrier type (NCT) subframe comprising added common pilots in comparison to the first subframe type, and wherein the added common pilots are used for tracking and channel estimation.

6. The method of claim 1, further comprising:

transmitting the first subframe type in the unlicensed spectrum after a predetermined number of transmissions of the second subframe type is identified.

7. The method of claim 1, wherein at least the transmitting the first subframe type and the transmitting the second subframe type are performed by an evolved Node B (eNB).

8. An apparatus for wireless communications, comprising:

means for comparing past transmission activity on an unlicensed spectrum to an activity threshold, wherein the activity threshold comprises one or more of;

a number of gated-ON periods in the unlicensed spectrum over a period of time, a duration of a number of gated-ON periods in the unlicensed spectrum over a period of time, and a number of synchronization (SYNC) subframes transmitted in the unlicensed spectrum over a period of time;

means for transmitting a first subframe type in the unlicensed spectrum during a next active transmission when the past transmission activity is greater than the activity threshold; and

means for transmitting a second subframe type in the unlicensed spectrum during a next active transmission when the past transmission activity is less than the activity threshold, the second subframe type comprising more pilots than the first subframe type.

9. The apparatus of claim 8, wherein the first subframe type comprises a legacy carrier type (LCT) subframe.

10. The apparatus of claim 8, wherein the first subframe type comprises a new carrier type (NCT) subframe.

11. The apparatus of claim 8, wherein the second subframe type comprises a legacy carrier type (LCT) subframe comprising added common pilots in comparison to the first subframe type, and wherein the added common pilots are used for tracking and channel estimation.

12. The apparatus of claim 8, wherein the second subframe type comprises a new carrier type (NCT) subframe comprising added common pilots in comparison to the first subframe type, and wherein the added common pilots are used for tracking and channel estimation.

13. The apparatus of claim 8, further comprising:

means for transmitting the first subframe type in the unlicensed spectrum after a predetermined number of transmissions of the second subframe type is identified.

14. The apparatus of claim 8, wherein the apparatus comprises an evolved Node B (eNB), the eNB comprising at least the means for transmitting the first subframe type and the means for transmitting the second subframe type.

15. 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;

compare past transmission activity on an unlicensed spectrum to an activity threshold, wherein the activity threshold comprises one or more of;

a number of gated-ON periods in the unlicensed spectrum over a period of time, a duration of a number of gated-ON periods in the unlicensed spectrum over a period of time, and a number of synchronization (SYNC) subframes transmitted in the unlicensed spectrum over a period of time;

transmit a first subframe type in the unlicensed spectrum during a next active transmission when the past transmission activity is greater than the activity threshold; and

transmit a second subframe type in the unlicensed spectrum during a next active transmission when the past transmission activity is less than the activity threshold, the second subframe type comprising more pilots than the first subframe type.

16. The apparatus of claim 15, wherein the first subframe type comprises a legacy carrier type (LCT) subframe.

17. The apparatus of claim 15, wherein the first subframe type comprises a new carrier type (NCT) subframe.

18. The apparatus of claim 15, wherein the second subframe type comprises a legacy carrier type (LCT) subframe comprising added common pilots in comparison to the first subframe type, and wherein the added common pilots are used for tracking and channel estimation.

19. The apparatus of claim 15, wherein the second subframe type comprises a new carrier type (NCT) subframe comprising added common pilots in comparison to the first subframe type, and wherein the added common pilots are used for tracking and channel estimation.

20. The apparatus of claim 15, wherein the instructions are executable by the processor to:

transmit the first subframe type in the unlicensed spectrum after a predetermined number of transmissions of the second subframe type is identified.

21. The apparatus of claim 15, wherein the processor comprises a processor of an evolved Node B (eNB).

22. 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:

compare past transmission activity on an unlicensed spectrum to an activity threshold, wherein the activity threshold comprises one or more of;

a number of gated-ON periods in the unlicensed spectrum over a period of time, a duration of a number of gated-ON periods in the unlicensed spectrum over a period of time, and a number of synchronization (SYNC) subframes transmitted in the unlicensed spectrum over a period of time;

transmit a first subframe type in the unlicensed spectrum during a next active transmission when the past transmission activity is greater than the activity threshold; and

transmit a second subframe type in the unlicensed spectrum during a next active transmission when the past transmission activity is less than the activity threshold, the second subframe type comprising more pilots than the first subframe type.

23. The computer program product of claim 22, wherein the second subframe type comprises a legacy carrier type (LCT) subframe comprising added common pilots in comparison to the first subframe type, and wherein the added common pilots are used for tracking and channel estimation.

24. The computer program product of claim 22, wherein the second subframe type comprises a new carrier type (NCT) subframe comprising added common pilots in comparison to the first subframe type, and wherein the added common pilots are used for tracking and channel estimation.

25. The computer program product of claim 22, wherein the instructions are executable by the processor to:

transmit the first subframe type in the unlicensed spectrum after a predetermined number of transmissions of the second subframe type is identified.