Method and apparatus for performing SL communication on basis of resources allocated by base station in NR V2X

1. A method for performing wireless communication by a first device, the method comprising:

receiving, form a base station, first downlink control information (DCI) for activating a configured sidelink (SL) grant, wherein the first DCI includes information related to a physical uplink control channel (PUCCH) resource for reporting SL hybrid automatic repeat request (HARD) feedback to the base station;

transmitting, to a second device through a physical sidelink shared channel (PSSCH), a medium access control (MAC) protocol data unit (PDU) based on the configured SL grant;

receiving, from the base station, second DCI for deactivating the configured SL grant;

transmitting, to the base station, a SL confirmation MAC control element (CE) in response to the second DCI; and

clearing the configured SL grant after the transmission of the SL confirmation MAC CE triggered by the second DCI for deactivating the configured SL grant.

2. The method of claim 1 , wherein, based on that at least one SL resource allocated by the configured SL grant is located before the transmission of the SL confirmation MAC CE, the PUCCH resource related to the at least one SL resource is valid.

3. The method of claim 1 , wherein, based on that (i) at least one SL resource allocated by the configured SL grant is located before the transmission of the SL confirmation MAC CE and (ii) the PUCCH resource related to the at least one SL resource is located before the transmission of the SL confirmation MAC CE, the PUCCH resource related to the at least one SL resource is valid.

4. The method of claim 1 , wherein, based on that (i) at least one SL resource allocated by the configured SL grant is located before the transmission of the SL confirmation MAC CE and (ii) the PUCCH resource related to the at least one SL resource is located after the transmission of the SL confirmation MAC CE, the PUCCH resource related to the at least one SL resource is valid.

5. The method of claim 1 , further comprising:

transmitting, to the base station, a positive acknowledgment (ACK) based on the PUCCH resource located after the transmission of the SL confirmation MAC CE.

6. The method of claim 5 , wherein, based on a failure to transmit the MAC PDU, the ACK is transmitted to the base station based on the PUCCH resource located after the transmission of the SL confirmation MAC CE.

7. The method of claim 6 , wherein a retransmission resource for the MAC PDU is not allocated to the first device by the base station based on the ACK.

8. The method of claim 1 , wherein, based on that at least one SL resource allocated by the configured SL grant is located after the transmission of the SL confirmation MAC CE, the at least one SL resource and the PUCCH resource related to the at least one SL resource are invalid.

9. The method of claim 1 , further comprising:

receiving, from the base station, third DCI including information related to a retransmission resource for the MAC PDU.

10. The method of claim 9 , wherein the third DCI does not include information related to a resource pool index.

11. The method of claim 10 , further comprising:

determining that a resource pool represented by the third DCI is same as a resource pool represented by the first DCI, based on that at least one of a configuration index or a HARQ process number included in the third DCI is same as at least one of a configuration index or a HARQ process number included in the first DCI.

12. The method of claim 9 , wherein a plurality of bits related to a resource pool index included in the third DCI are all set to zero.

13. The method of claim 9 , wherein, based on that information related to a resource pool index included in the third DCI and information related to a resource pool index included in the first DCI are different, at least one of a same configuration index or a same HARQ process number is not used for different resource pools.

14. A first device adapted to perform wireless communication, the first device comprising:

one or more memories storing instructions;

one or more transceivers; and

one or more processors connected to the one or more memories and the one or more transceivers, wherein the one or more processors execute the instructions to:

control the one or more transceivers to receive, form a base station, first downlink control information (DCI) for activating a configured sidelink (SL) grant, wherein the first DCI includes information related to a physical uplink control channel (PUCCH) resource for reporting SL hybrid automatic repeat request (HARD) feedback to the base station;

control the one or more transceivers to transmit, to a second device through a physical sidelink shared channel (PSSCH), a medium access control (MAC) protocol data unit (PDU) based on the configured SL grant;

control the one or more transceivers to receive, from the base station, second DCI for deactivating the configured SL grant;

control the one or more transceivers to transmit, to the base station, a SL confirmation MAC control element (CE) in response to the second DCI; and

clear the configured SL grant after the transmission of the SL confirmation MAC CE triggered by the second DCI for deactivating the configured SL grant.

15. The first device of claim 14 , wherein, based on that at least one SL resource allocated by the configured SL grant is located before the transmission of the SL confirmation MAC CE, the PUCCH resource related to the at least one SL resource is valid.

16. The first device of claim 14 , wherein, based on that (i) at least one SL resource allocated by the configured SL grant is located before the transmission of the SL confirmation MAC CE and (ii) the PUCCH resource related to the at least one SL resource is located before the transmission of the SL confirmation MAC CE, the PUCCH resource related to the at least one SL resource is valid.

17. The first device of claim 14 , wherein, based on that (i) at least one SL resource allocated by the configured SL grant is located before the transmission of the SL confirmation MAC CE and (ii) the PUCCH resource related to the at least one SL resource is located after the transmission of the SL confirmation MAC CE, the PUCCH resource related to the at least one SL resource is valid.

18. A processing device adapted to control a first device, the processing device comprising:

one or more processors; and

one or more memories operably connected to the one or more processors and storing instructions, wherein the one or more processors execute the instructions to:

receive, form a base station, first downlink control information (DCI) for activating a configured sidelink (SL) grant, wherein the first DCI includes information related to a physical uplink control channel (PUCCH) resource for reporting SL hybrid automatic repeat request (HARD) feedback to the base station;

transmit, to a second device through a physical sidelink shared channel (PSSCH), a medium access control (MAC) protocol data unit (PDU) based on the configured SL grant;

receive, from the base station, second DCI for deactivating the configured SL grant;

transmit, to the base station, a SL confirmation MAC control element (CE) in response to the second DCI; and

clear the configured SL grant after the transmission of the SL confirmation MAC CE triggered by the second DCI for deactivating the configured SL grant.

19. The processing device of claim 18 , wherein, based on that (i) at least one SL resource allocated by the configured SL grant is located before the transmission of the SL confirmation MAC CE and (ii) the PUCCH resource related to the at least one SL resource is located before the transmission of the SL confirmation MAC CE, the PUCCH resource related to the at least one SL resource is valid.

20. The processing device of claim 18 , wherein, based on that (i) at least one SL resource allocated by the configured SL grant is located before the transmission of the SL confirmation MAC CE and (ii) the PUCCH resource related to the at least one SL resource is located after the transmission of the SL confirmation MAC CE, the PUCCH resource related to the at least one SL resource is valid.