Method and device for transmitting SCI in NR V2X

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

transmitting, through a first physical sidelink control channel (PSCCH), a first sidelink control information (SCI) based on a first resources;

transmitting, through a first physical sidelink shared channel (PSSCH) related to the first PSCCH, a second SCI based on the first resource,

wherein at least one of the first SCI or the second SCI includes information related to a second resource, and

wherein a transport block (TB) is not transmitted through the first PSSCH;

transmitting, to a second device through a second PSCCH, a third SCI based on the second resource; and

transmitting, to the second device through a second PSSCH related to the second PSCCH, a fourth SCI and the TB based on the second resource.

2. The method of claim 1 , wherein the first PSCCH and the first PSSCH are transmitted to reserve the second resource.

3. The method of claim 1 , wherein a number of subchannels included in the first resource is less than a number of subchannels included in the second resource.

4. The method of claim 3 , wherein the number of subchannels included in the first resource is one.

5. The method of claim 1 , wherein the first SCI transmitted through the first PSCCH includes information informing that the TB is not transmitted through the first PSSCH.

6. The method of claim 1 , wherein the first device informs that the TB is not transmitted through the first PSSCH, based on a combination of information related to modulation and coding scheme (MCS) included in the first SCI transmitted through the first PSCCH and information related to redundancy version (RV) included in the second SCI transmitted through the first PSSCH.

7. The method of claim 6 , wherein the information related to the MCS is 26, and the information related to the RV is 1.

8. The method of claim 1 , wherein the second SCI transmitted through the first PSSCH is rate-matched on a resource related to the first PSSCH.

9. The method of claim 8 , wherein the second SCI transmitted through the first PSSCH is mapped from N-th symbol to a last symbol on the resource related to the first PSSCH, and then mapped from 1st symbol to (N−1)-th symbol on the resource related to the first PSSCH,

wherein the 1st symbol on the resource related to the first PSSCH is a symbol related to automatic gain control (AGC), and

wherein the N is a positive integer greater than or equal to 2.

10. The method of claim 8 , wherein the second SCI transmitted through the first PSSCH is mapped from N-th symbol to a last symbol on the resource related to the first PSSCH, and then mapped from 2nd symbol to (N−1)-th symbol on the resource related to the first PSSCH,

wherein a specific value is mapped to 1st symbol on the resource related to the first PSSCH, and

wherein the 1st symbol on the resource related to the first PSSCH is a symbol related to automatic gain control (AGC), and

wherein the N is a positive integer greater than or equal to 3.

11. The method of claim 10 , wherein the N-th symbol is a symbol to which 1st DMRS is mapped on the resource related to the first PSSCH.

12. The method of claim 8 , wherein the second SCI transmitted through the first PSSCH is mapped from 2nd symbol to a last symbol on the resource related to the first PSSCH,

wherein a specific value is mapped to 1st symbol on the resource related to the first PSSCH, and

wherein the 1st symbol on the resource related to the first PSSCH is a symbol related to automatic gain control (AGC).

13. The method of claim 1 , wherein the second SCI transmitted through the first PSSCH is mapped from N-th symbol to (N+K)-th symbol on a resource related to the first PSSCH,

wherein a specific value is mapped to a resource to which the second SCI is not mapped among the resource related to the first PSSCH, and

wherein the N and the K are positive integers.

14. A first device configured 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:

transmit, through a first physical sidelink control channel (PSCCH), a first sidelink control information (SCI) based on a first resources;

transmit, through a first physical sidelink shared channel (PSSCH) related to the first PSCCH, a second SCI based on the first resource,

wherein at least one of the first SCI or the second SCI includes information related to a second resource, and

wherein a transport block (TB) is not transmitted through the first PSSCH;

transmit, to a second device through a second PSCCH, a third SCI based on the second resource; and

transmit, to the second device through a second PSSCH related to the second PSCCH, a fourth SCI and the TB based on the second resource.

15. The first device of claim 14 , wherein the first PSCCH and the first PSSCH are transmitted to reserve the second resource.

16. The first device of claim 14 , wherein a number of subchannels included in the first resource is less than a number of subchannels included in the second resource.

17. The first device of claim 16 , wherein the number of subchannels included in the first resource is one.

18. The first device of claim 14 , wherein the first SCI transmitted through the first PSCCH includes information informing that the TB is not transmitted through the first PSSCH.

19. The first device of claim 14 , wherein the first device informs that the TB is not transmitted through the first PSSCH, based on a combination of information related to modulation and coding scheme (MCS) included in the first SCI transmitted through the first PSCCH and information related to redundancy version (RV) included in the second SCI transmitted through the first PSSCH.

20. An apparatus configured to control a first user equipment (UE) performing wireless communication, the apparatus 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:

transmit, through a first physical sidelink control channel (PSCCH), a first sidelink control information (SCI) based on a first resources;

transmit, through a first physical sidelink shared channel (PSSCH) related to the first PSCCH, a second SCI based on the first resource,

wherein at least one of the first SCI or the second SCI includes information related to a second resource, and

wherein a transport block (TB) is not transmitted through the first PSSCH;

transmit, to a second UE through a second PSCCH, a third SCI based on the second resource; and

transmit, to the second UE through a second PSSCH related to the second PSCCH, a fourth SCI and the TB based on the second resource.