Harq procedure and frame structure for LTE cells on unlicensed spectrum
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.
1. A user equipment (UE) comprising:
at least one antenna configured to communicate with a base station; and
processing circuitry configured to receive data and control information through the at least one antenna, the data and control information received 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,
wherein the unlicensed frame is not aligned with a primary cell (Pcell) frame, and
wherein a duration of the unlicensed frame is 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.
2. The UE as set forth in claim 1 , wherein mapping of signals is according to a timing of the unlicensed frame.
3. The UE as set forth in claim 1 , wherein the duration of the unlicensed frame is fixed, or signaled by another serving cell.
4. The UE as set forth in claim 1 , 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.
5. The UE as set forth in claim 1 , wherein the processing circuitry 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.
6. The UE as set forth in claim 1 , 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.
7. The UE as set forth in claim 6 , wherein the DL-UL pattern configuration is according to:
ON duration
1
2
3
4
5
6
7
8
9
10
SF #0
D/U
D/U
D
D
D
D
D
D
D
D
SF #1
D/U
S
D
D
D
D
D
D
D
SF #2
U
S
S
D
D
D
D
D
SF #3
U
U
S
S
D
D
D
SF #4
U
U
U
S
S
D
SF #5
U
U
U
U
S
SF #6
U
U
U
U
SF #7
U
U
U
SF #8
U
U
SF #9
U.
8. The UE as set forth in claim 6 , wherein at least one of: a configuration of the DL-UL ratio, a special sub-frame location, or the unlicensed frame duration, or unlicensed frame configuration information, is signaled from another serving cell with UE-common or UE-specific signaling or signaled from the unlicensed spectrum carrier.
9. A method comprising:
receiving data and control information through at least one antenna, the data and control information received 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,
wherein the unlicensed frame is not aligned with a primary cell (Pcell) frame, and
wherein a duration of the unlicensed frame is 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.
10. The method as set forth in claim 9 , wherein mapping of signals is according to a timing of the unlicensed frame.
11. The method as set forth in claim 9 , wherein at least one of:
the duration of the unlicensed frame is fixed, or signaled by another serving cell; or
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.
12. The method as set forth in claim 9 , further comprising:
performing an UL hybrid automatic repeat request (HARQ) process, 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.
13. The method as set forth in claim 9 , 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, and
wherein at least one of: a configuration of the DL-UL ratio, a special sub-frame location, or the unlicensed frame duration, or unlicensed frame configuration information, is signaled from another serving cell with UE-common or UE-specific signaling or signaled from the unlicensed spectrum carrier.
14. A base station (BS) comprising:
at least one antenna configured to communicate with a user equipment (UE); and processing circuitry configured to send data and control information through the at least one antenna 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,
wherein the unlicensed frame is not aligned with a primary cell (Pcell) frame, and
wherein a duration of the unlicensed frame is 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.
15. The BS as set forth in claim 14 , wherein mapping of signals is according to a timing of the unlicensed frame.
16. The BS as set forth in claim 14 , wherein at least one of:
the duration of the unlicensed frame fixed, or signaled by another serving cell; or
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 BS as set forth in claim 14 , 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.
18. The BS as set forth in claim 17 , wherein at least one of: a configuration of the DL-UL ratio, a special sub-frame location, or the unlicensed frame duration, or unlicensed frame configuration information, is signaled from another serving cell with UE-common or UE-specific signaling or signaled from the unlicensed spectrum carrier.