Method and apparatus for providing HARQ feedback in wireless communication system

1. A method performed by a first user equipment (UE) in a wireless communication system, the method comprising:

receiving first sidelink control information (SCI) via a physical sidelink control channel (PSCCH);

receiving second SCI via a physical sidelink shared channel (PSSCH);

identifying a HARQ feedback type for a groupcast based on the second SCI; and

transmitting HARQ feedback information for the PSSCH based on the HARQ feedback type, via a physical sidelink feedback channel (PSFCH).

2. The method of claim 1 , further comprising:

identifying a resource for the PSFCH,

wherein the resource for the PSFCH is determined based on an identity of the first UE and an identity of a second UE.

3. The method of claim 2 , wherein the identity of the first UE is indicated by a higher layer.

4. The method of claim 2 , wherein the identity of the second UE is provided by the second SCI.

5. The method of claim 2 ,

wherein the resource for the PSFCH corresponds to (UEindexInGroup + Aspect) mod NPFSCH,

wherein the UEindexInGroup indicates the identity of the first UE,

wherein the Aspect indicates the identity of the second UE corresponding to a physical layer source identifier, and

wherein the NPFSCH indicates a number of PSFCH resources available for transmitting the HARQ feedback information.

6. The method of claim 1 , further comprising:

identifying, based on the first SCI, priority information for a plurality of PSFCHs; and

in case that a transmission of a first PSFCH would overlaps in time with a reception of a second PSFCH, performing the transmission of the first PSFCH or the reception of the second PSFCH based on the priority information.

7. The method of claim 1 , further comprising:

identifying, based on the first SCI, priority information for a plurality of PSFCHs; and

transmitting, based on the priority information, one or more PSFCHs among the plurality of PSFCHs.

8. A first user equipment (UE) in a wireless communication system, the first UE comprising:

a transceiver; and

at least one processor coupled with the transceiver and configured to:

receive first sidelink control information (SCI) via a physical sidelink control channel (PSCCH),

receive second SCI via a physical sidelink shared channel (PSSCH),

identify a HARQ feedback type for a groupcast based on the second SCI, and

transmit HARQ feedback information for the PSSCH based on the HARQ feedback type, via a physical sidelink feedback channel (PSFCH).

9. The first UE of claim 8 ,

wherein the at least one processor is further configured to identify a resource for the PSFCH, and

wherein the resource for the PSFCH is determined based on an identity of the first UE and an identity of a second UE.

10. The first UE of claim 9 , wherein the identity of the first UE is indicated by a higher layer.

11. The first UE of claim 9 , wherein the identity of the second UE is provided by the second SCI.

12. The first UE of claim 9 ,

wherein the resource for the PSFCH corresponds to (UEindexInGroup + Aspect) mod NPFSCH,

wherein the UEindexInGroup indicates the identity of the first UE,

wherein the Aspect indicates the identity of the second UE corresponding to a physical layer source identifier, and

wherein the NPFSCH indicates a number of PSFCH resources available for transmitting the HARQ feedback information.

13. The first UE of claim 8 , wherein the at least one processor is further configured to:

identify, based on the first SCI, priority information for a plurality of PSFCHs, and

in case that a transmission of a first PSFCH would overlaps in time with a reception of a second PSFCH, perform the transmission of the first PSFCH or the reception of the second PSFCH based on the priority information.

14. The first UE of claim 8 , wherein the at least one processor is further configured to:

identify, based on the first SCI, priority information for a plurality of PSFCHs, and

transmit, based on the priority information, one or more PSFCHs among the plurality of PSFCHs.

15. The method of claim 1 , wherein the HARQ feedback type is identified as a first HARQ feedback type in which the HARQ feedback information includes only NACK or a second HARQ feedback type in which the HARQ feedback information includes ACK or NACK.

16. The first UE of claim 8 , wherein the HARQ feedback type is identified as a first HARQ feedback type in which the HARQ feedback information includes only NACK or a second HARQ feedback type in which the HARQ feedback information includes ACK or NACK.