HARQ DESIGN FOR LTE IN UNLICENSED SPECTRUM UTILIZING INDIVIDUAL ACK/NACK

• US 20150049708A1
• Filed: 08/11/2014
• Published: 02/19/2015
• Est. Priority Date: 08/13/2013
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Damnjanovic, Aleksandar, Bhushan, Naga, Chen, Wanshi, Malladi, Durga Prasad, Wei, Yongbin, Luo, Tao, Ji, Tingfang, Gaal, Peter
• Granted Patent: US 10,326,577 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04L 1/1812 Hybrid protocols; Hybrid automatic repeat request [HARQ]
• CPC Class Codes: H04L 1/1829 Arrangements specially adapted for the receiver end
• CPC Class Codes: H04L 1/1835 Buffer management
• CPC Class Codes: H04L 1/1854 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 1/1874 Buffer management
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0055 Physical resource allocation for ACK/NACK for physical mapping arrangements in ARQ protocols H04L1/1861

Abstract

Methods, systems, and apparatuses are described for wireless communications. In one method, a sequence number corresponding to a data frame and one or more data subframes of the data frame may be transmitted over an unlicensed spectrum to a user equipment (UE), and hybrid automatic repeat request (HARQ) feedback for the one or more data subframes may be received over the unlicensed spectrum, from the UE, when the sequence number corresponding to the data frame is received by the UE in a specified order. In another method, a sequence number corresponding to a data frame and HARQ feedback may be transmitted over an unlicensed spectrum to a UE, and one or more data subframes may be received over the unlicensed spectrum, from the UE, in response to the HARQ feedback when the sequence number corresponding to the data frame is received by the UE in a specified order.

Claims

1. A method for wireless communications, comprising:

transmitting, over an unlicensed spectrum to a user equipment (UE), a sequence number corresponding to a data frame and one or more data subframes of the data frame; and

receiving, over the unlicensed spectrum from the UE, hybrid automatic repeat request (HARQ) feedback for the one or more data subframes when the sequence number corresponding to the data frame is received by the UE in a specified order.

2. The method of claim 1, wherein HARQ feedback is not transmitted by the UE for the one or more data subframes when the sequence number corresponding to the data frame is received by the UE out of order.

3. The method of claim 1, further comprising:

transmitting, over the unlicensed spectrum to the UE, a sequence number corresponding to a subsequent data frame and one or more data subframes of the subsequent data frame; and

receiving, over the unlicensed spectrum from the UE, HARQ feedback for the one or more data subframes of the subsequent data frame when the sequence number for the subsequent data frame is received by the UE in the specified order.

4. The method of claim 1, wherein receiving, over the unlicensed spectrum from the UE, HARQ feedback for the one or more data subframes comprises:

receiving a separate HARQ feedback message for each of the one or more data subframes.

5. The method of claim 1, wherein receiving, over the unlicensed spectrum from the UE, HARQ feedback for the one or more data subframes comprises:

receiving HARQ feedback for a subset of the one or more data subframes during the data frame; and

receiving HARQ feedback for a remaining subset of the one or more data subframes during a next data frame.

6. The method of claim 1, wherein receiving, over the unlicensed spectrum from the UE, HARQ feedback for the one or more data subframes comprises:

receiving HARQ feedback for each of the one or more data subframes during each of one or more corresponding uplink subframes, wherein each corresponding uplink subframe occurs during the data frame or during a next data frame.

7. The method of claim 1, further comprising:

performing clear channel assessment (CCA) to determine availability of the unlicensed spectrum; and

accessing the unlicensed spectrum during the data frame when a determination is made that the unlicensed spectrum is available.

8. The method of claim 1, further comprising:

transmitting a request to send (RTS) signal to request channel access over an unlicensed spectrum; and

receiving, in response to the RTS signal, a clear to send (CTS) signal when the unlicensed spectrum is available.

9. The method of claim 1, further comprising:

transmitting a clear to send (CTS) signal when the unlicensed spectrum is available for transmission.

10. An apparatus for wireless communications, comprising:

a processor; and

memory communicatively coupled to the processor;

wherein the processor is configured to;

transmit, over an unlicensed spectrum to a user equipment (UE), a sequence number corresponding to a data frame and one or more data subframes of the data frame; and

receive, over the unlicensed spectrum from the UE, hybrid automatic repeat request (HARQ) feedback for the one or more data subframes when the sequence number corresponding to the data frame is received by the UE in a specified order.

11. The apparatus of claim 10, wherein HARQ feedback is not transmitted by the UE for the one or more data subframes when the sequence number corresponding to the data frame is received by the UE out of order.

12. The apparatus of claim 10, wherein the processor is further configured to:

transmit, over the unlicensed spectrum to the UE, a sequence number corresponding to a subsequent data frame and one or more data subframes of the subsequent data frame; and

receive, over the unlicensed spectrum from the UE, HARQ feedback for the one or more data subframes of the subsequent data frame when the sequence number for the subsequent data frame is received by the UE in the specified order.

13. The apparatus of claim 10, wherein the processor is further configured to:

receive a separate HARQ feedback message for each of the one or more data subframes.

14. The apparatus of claim 10, wherein the processor is further configured to:

receive HARQ feedback for a subset of the one or more data subframes during the data frame; and

receive HARQ feedback for a remaining subset of the one or more data subframes during a next data frame.

15. The apparatus of claim 10, wherein the processor is further configured to:

receive HARQ feedback for each of the one or more data subframes during each of one or more corresponding uplink subframes, wherein each corresponding uplink subframe occurs during the data frame or during a next data frame.

16. The apparatus of claim 10, wherein the processor is further configured to:

perform clear channel assessment (CCA) to determine availability of the unlicensed spectrum; and

access the unlicensed spectrum during the data frame when a determination is made that the unlicensed spectrum is available.

17. The apparatus of claim 10, wherein the processor is further configured to:

transmit a request to send (RTS) signal to request channel access over an unlicensed spectrum; and

receive, in response to the RTS signal, a clear to send (CTS) signal when the unlicensed spectrum is available for transmission.

18. The apparatus of claim 10, wherein the processor is further configured to:

transmit a clear to send (CTS) signal when the unlicensed spectrum is available.

19. A method for wireless communications, comprising:

transmitting, over an unlicensed spectrum to a user equipment (UE), a sequence number corresponding to a data frame and hybrid automatic repeat request (HARQ) feedback; and

receiving, over the unlicensed spectrum from the UE, one or more data subframes in response to the HARQ feedback when the sequence number corresponding to the data frame is received by the UE in a specified order.

20. The method of claim 19, wherein the one or more data subframes are not transmitted by the UE when the sequence number corresponding to the data frame is received by the UE out of order.

21. The method of claim 19, further comprising:

transmitting, over the unlicensed spectrum to the UE, a sequence number corresponding to a subsequent data frame and subsequent HARQ feedback; and

receiving, over the unlicensed spectrum from the UE, one or more additional data subframes in response to the subsequent HARQ feedback when the sequence number for the subsequent data frame is received by the UE in the specified order.

22. The method of claim 19, wherein:

the HARQ feedback comprises one or more HARQ feedback messages; and

receiving, over the unlicensed spectrum from the UE, one or more data subframes comprises receiving a separate data subframe for each of the one or more HARQ feedback messages.

23. The method of claim 19, wherein receiving, over the unlicensed spectrum from the UE, one or more data subframes comprises:

receiving each of the one or more data subframes during each of one or more corresponding uplink subframes, wherein each corresponding uplink subframe occurs during the data frame.

24. The method of claim 19, further comprising:

performing clear channel assessment (CCA) to determine availability of the unlicensed spectrum; and

accessing the unlicensed spectrum during the data frame when a determination is made that the unlicensed spectrum is available.

25. An apparatus for wireless communications, comprising:

a processor; and

memory communicatively coupled to the processor;

wherein the processor is configured to;

transmit, over an unlicensed spectrum to a user equipment (UE), a sequence number corresponding to a data frame and hybrid automatic repeat request (HARQ) feedback; and

receive, over the unlicensed spectrum from the UE, one or more data subframes in response to the HARQ feedback when the sequence number corresponding to the data frame is received by the UE in a specified order.

26. The apparatus of claim 25, wherein the one or more data subframes are not transmitted by the UE when the sequence number corresponding to the data frame is received by the UE out of order.

27. The apparatus of claim 25, wherein the processor is further configured to:

transmit, over the unlicensed spectrum to the UE, a sequence number corresponding to a subsequent data frame and subsequent HARQ feedback; and

receive, over the unlicensed spectrum from the UE, one or more additional data subframes in response to the subsequent HARQ feedback when the sequence number for the subsequent data frame is received by the UE in the specified order.

28. The apparatus of claim 25, wherein:

the HARQ feedback comprises one or more HARQ feedback messages; and

the processor is further configured to receive, over the unlicensed spectrum from the UE, one or more data subframes comprise instructions executable by the processor to receive a separate data subframe for each of the one or more HARQ feedback messages.

29. The apparatus of claim 25, wherein the processor is further configured to:

receive each of the one or more data subframes during each of one or more corresponding uplink subframes, wherein each corresponding uplink subframe occurs during the data frame.

30. The apparatus of claim 25, wherein the processor is further configured to:

perform clear channel assessment (CCA) to determine availability of the unlicensed spectrum; and

access the unlicensed spectrum during the data frame when a determination is made that the unlicensed spectrum is available.