HARQ PROCEDURE AND FRAME STRUCTURE FOR LTE CELLS ON UNLICENSED SPECTRUM

• US 20150365931A1
• Filed: 06/02/2015
• Published: 12/17/2015
• Est. Priority Date: 06/11/2014
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Ng, Boon Loong, Papasakellariou, Aris, Novlan, Thomas David, Li, Ying
• Granted Patent: US 9,917,676 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 1/1812 Hybrid protocols; Hybrid automatic repeat request [HARQ]
• CPC Class Codes: H04L 1/1822 involving configuration of automatic repeat request [ARQ] with parallel processes
• CPC Class Codes: H04L 1/1861 Physical mapping arrangements for ACK signaling see also H04L5/0053
• CPC Class Codes: H04L 1/1887 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 1/1893 Physical mapping arrangements physical resource mapping in general H04L5/00
• CPC Class Codes: H04L 1/1896 ARQ related signaling
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/541 using the level of interference
• CPC Class Codes: H04W 84/042 Public Land Mobile systems, e.g. cellular systems

Abstract

A user equipment (UE) is configured to perform a Hybrid Automatic Repeat Request (HARQ) in an un-licensed system. The UE includes at least one antenna configured to communicate with a base station. The UE also includes processing circuitry. The processing circuitry is configured to: send and receive data through the at least one antenna, in response to failing to decode a transport block transmitted by a first downlink carrier, transmit a negative acknowledgement message to the base station, and receive a re-transmission of the transport block from a second downlink carrier. The first downlink carrier comprises a unlicensed spectrum carrier and the second downlink carrier is different from the first downlink carrier.

Claims

1. A user equipment (UE) comprising:

at least one antenna configured to communicate with a base station; and

processing circuitry configured to;

send and receive data through the at least one antenna,

in response to failing to decode a transport block transmitted by a first downlink carrier, transmit a negative acknowledgement message to the base station, and

receive a re-transmission of the transport block from a second downlink carrier, wherein the first downlink carrier comprises a unlicensed spectrum carrier and the second downlink carrier is different from the first downlink carrier.

2. The UE as set forth in claim 1, wherein the processing circuitry is configured to receive, via the at least one antenna, a downlink control information (DCI) scheduling downlink assignment for the first downlink carrier.

3. The UE as set forth in claim 2, wherein the DCI is received on the second carrier.

4. The UE as set forth in claim 2, wherein the DCI comprises a Carrier Indicator Field (CIF) configured to indicate a carrier on which a physical downlink shared channel (PDSCH) is transmitted.

5. The UE as set forth in claim 4, when the first carrier is OFF, and the CIF is configured to point to a LTE-U/LAA carrier, the corresponding PDSCH that belongs to a HARQ process on the LTE-U/LAA carrier is transmitted on the second DL carrier.

6. The UE as set forth in claim 5, wherein the PDSCH on the second DL carrier carrying data from the HARQ process of the LTE-U/LAA carrier is only a retransmission.

7. The UE as set forth in claim 6, wherein the HARQ process associated with the retransmission is indicated by the HARQ process number in the DCI.

8. The UE as set forth in claim 1, wherein the processing circuitry is configured to determine an ON/OFF status of the first downlink carrier from a signaling by the base station.

9. The UE as set forth in claim 8, wherein a bit in the DCI is configured to indicate the ON/OFF status on the LTE-U/LAA carrier that is indicated by the CIF.

10. The UE as set forth in claim 1, wherein the processing circuitry is configured to receive the receive the re-transmission of the transport block from the second downlink carrier in response to determining that the first downlink carrier is in an OFF period in which one of:

no signals are transmitted and only discovery reference signals are transmitted.

11. A user equipment (UE) comprising:

at least one antenna configured to communicate with a base station; and

processing circuitry configured to;

send and receive data control information through the at least one antenna, and

receive the data and control information in an unlicensed frame on an unlicensed spectrum carrier, the unlicensed frame comprising a number of downlink (DL) sub-frames followed by special sub-frame followed by an uplink (UL) sub-frame.

12. The UE as set forth in claim 11, wherein the unlicensed frame is not aligned with a primary cell (Pcell) frame.

13. The UE as set forth in claim 12, wherein mapping of signals is according to the timing of the unlicensed frame.

14. The UE as set forth in claim 11, wherein a start time of the unlicensed frame is signaled from another serving cell with UE-common or UE-specific signaling .

15. The UE as set forth in claim 11, wherein a duration of the unlicensed frame is one of:

fixed, signaled by another serving cell, or signaled from the unlicensed spectrum carrier using a UE-common or a UE-specific (E)PDCCH, in a first DL sub-frame of the unlicensed frame.

16. The UE as set forth in claim 11, wherein the number of DL sub-frames comprises a first six sub-frames and the special sub-frame comprise one sub-frame followed by three UL sub-frames, and wherein a duration of the unlicensed frame is ten milliseconds.

17. The UE as set forth in claim 11, wherein the processing circuity is configured to perform an UL hybrid automatic repeat request (HARQ) process, and wherein a UL HARQ timing is as follows:

for DL transport blocks received in DL sub-frame #0 and DL sub-frame #1 a UL HARQ acknowledgement (ACK) is transmitted in UL sub-frame #7, for DL transport blocks received in DL sub-frame #2 and DL sub-frame #3 the UL HARQ ACK is transmitted in UL sub-frame #8, and for DL transport blocks received in DL sub-frame #4 and DL sub-frame #5 the UL HARQ ACK is transmitted in UL sub-frame #9.

18. The UE as set forth in claim 11, wherein the unlicensed frame comprises a DL-UL pattern configuration, wherein depending upon a configured DL-UL ratio, the DL-UL pattern is a function of an ON duration configuration.

19. The UE as set forth in claim 11, wherein the DL-UL pattern configuration is according to:

20. The UE as set forth in claim 11, wherein at least one of:

a configuration of the DL/UL ratio, a special sub-frame location, or the unlicensed frame duration, or the unlicensed frame configuration information, is signaled from another serving cell with UE-common or UE-specific signaling or signaled from the unlicensed spectrum carrier.