Resource selection method of sidelink terminal in wireless communication system, and terminal using method

1. A resource selecting method of a sidelink terminal in a wireless communication system, the resource selecting method comprising:

determining resource selection sub-windows in a resource selection window based on a repeated transmission number for a sidelink message; and

selecting resource for transmitting the sidelink message within each of the resource selection sub-window,

wherein the repeated transmission number includes the number of initial transmission and retransmission for the sidelink message.

2. The resource selecting method of claim 1 , wherein a size of the resource selection sub-window for retransmission is determined as a largest integer less than a value obtained by dividing the size of the resource selection window by the repeated transmission number.

3. The resource selecting method of claim 2 , wherein the size of the resource selection sub-window for the initial transmission is determined as a value obtained by subtracting a value obtained by multiplying the retransmission number by the size of the resource selection sub-window from the resource selection window.

4. The resource selecting method of claim 1 , wherein the repeated transmission number is determined based on at least one of capability of the terminal and a receiving terminal receiving the sidelink message and a requirement for the sidelink message.

5. The resource selecting method of claim 4 , wherein the requirement is related to latency or reliability.

6. The resource selecting method of claim 4 , wherein the terminal receives information on the capability of the receiving terminal from the receiving terminal.

7. The resource selecting method of claim 4 , wherein the capability includes hybrid automatic repeat request (HARQ) round trip time (RTT) related processing capability of the terminal and the receiving terminal.

8. The resource selecting method of claim 7 , wherein the capability is a relatively lower value among the HARQ RTT related processing capabilities of the respective terminal and the receiving terminal.

9. The resource selecting method of claim 4 , wherein the terminal determines a number of resource selection sub-windows corresponding to the maximum repeated transmission available number when the maximum repeated transmission available number based on the capability is greater than a required repeated transmission number required for the requirement, and the terminal selects the resource within the number of resource selection sub-windows corresponding to the required repeated transmission number.

10. The resource selecting method of claim 9 , wherein the terminal selects the resource within the number of resource selection sub-windows corresponding to the required repeated transmission number in earliest order on a time axis.

11. The resource selecting method of claim 4 , wherein the terminal determines a number of resource selection sub-windows corresponding to the maximum repeated transmission available number when the maximum repeated transmission available number based on the capability is less than the required repeated transmission number required for the requirement, and the terminal selects the resource within the determined resource selection sub-windows.

12. The resource selecting method of claim 1 , wherein the repeated transmission number is determined by a plurality of sidelink message transmission per resource selection sub-frame and a unit of a HARQ feedback for the transmission.

13. The resource selecting method of claim 1 , wherein the terminal selects resource for the sidelink message transmission within each of the resource selection sub-windows excluding the last resource selection sub-window on the time axis.

14. The resource selecting method of claim 1 , wherein the terminal selects the resource within each of the resource selection sub-windows including resource at a specific ratio or higher, and the specific ratio is a ratio of resource whose reference signal received power (RSRP) is equal to or lower than a threshold value among resources included in each of the resource selection sub-windows.

15. The resource selecting method of claim 14 , wherein the specific ratio related to the resource selection sub-window for the initial transmission and the specific ratio related to the resource selection sub-window for the retransmission are different from each other.

16. The resource selecting method of claim 1 , wherein the repeated transmission number relates to an HARQ feedback information transmission number of a receiving terminal receiving the sidelink message.

17. A user equipment (UE) comprising:

a transceiver configured to transmit and receive a wireless signal; and

a processor operably coupled to the transceiver,

wherein the processor is configured

to determine resource selection sub-windows in a resource selection window based on a repeated transmission number for a sidelink message and

to select resource for transmitting the sidelink message within each of the resource selection sub-window,

wherein the repeated transmission number includes the number of initial transmission and retransmission for the sidelink message.

18. The UE of claim 17 , wherein the UE may be a terminal which communicates with at least one of a mobile terminal, a network, or an autonomous driving vehicle other than the terminal.