Transmission of sidelink-synchronization signal block of NR V2X

1. A method for transmitting a sidelink-synchronization signal block (SL-SSB) by a first apparatus, the method including:

generating the SL-SSB including a sidelink primary synchronization signal (SPSS), a sidelink secondary synchronization signal (SSSS) and a sidelink physical broadcast channel (PSBCH);

determining a first resource capable of transmitting a first SL-SSB;

determining a second resource based on a slot format of the first SL-SSB among the first resource; and

transmitting the first SL-SSB to a second apparatus based on the second resource,

wherein the first resource is determined based on a starting symbol index and an ending symbol index in a slot for the first SL-SSB, and

wherein the second resource represents a resource that overlaps with an uplink (UL) resource or a sidelink (SL) resource based on the slot format among the first resource.

2. The method of claim 1 , further including:

receiving a second SL-SSB from a third apparatus;

determining a third resource among the first resource based on the slot format of the first SL-SSB; and

transmitting the first SL-SSB to the second apparatus based on the received second SL-SSB and the third resource,

wherein the third resource represents a resource that overlaps with an UL resource or a SL resource among the first resource.

3. The method of claim 2 , wherein the transmitting the first SL-SSB to the second apparatus based on the third resource includes:

transmitting the first SL-SSB to the second apparatus through a resource of a pre-configured resource unit that most precedes in time among the third resource.

4. The method of claim 2 ,

wherein the transmitting the first SL-SSB to the second apparatus based on the third resource includes:

deriving a sensing resource among the third resource based on a sensing operation considering a pre-configured resource unit; and

transmitting the first SL-SSB to the second apparatus through the sensing resource.

5. The method of claim 4 , wherein a reference signal strength indication (RSSI) value is smallest among a plurality of RSSI values determined based on a plurality of resources of the pre-configured resource unit included in the third resource.

6. The method of claim 4 ,

wherein a RSSI value determined based on the sensing resource is smaller than a pre-configured threshold, and

wherein the sensing resource is the most advanced in time among a plurality of resources having an RSSI value smaller than the pre-configured threshold, and the plurality of resources are based on the previously configured resource unit.

7. The method of claim 2 ,

wherein the second SL-SSB includes first resource indication information related to a physical sidelink broadcast channel (PSBCH), and

wherein the first resource is determined based on the first resource indication information.

8. The method of claim 1 , wherein the first resource is determined based on the starting symbol index and a first resource length in the slot for the first SL-SSB.

9. The method of claim 1 , wherein the transmitting the first SL-SSB to the second apparatus includes:

transmitting location information of the first SL-SSB to the second apparatus through a physical sidelink broadcast channel (PSBCH).

10. The method of claim 9 , wherein the location information of the first SL-SSB is included in SL system information related to the PSBCH or a demodulation reference signal (DMRS) related to the PSBCH.

11. A first apparatus transmitting a sidelink-synchronization signal block (SL-SSB), the first apparatus including:

at least one memory storing instructions;

at least one transceiver; and

at least one processor connecting the at least one memory and the at least one transceiver,

wherein the at least one processor is configured to:

generate the SL-SSB including a sidelink primary synchronization signal (SPSS), a sidelink secondary synchronization signal (SSSS) and a sidelink physical broadcast channel (PSBCH);

determine a first resource capable of transmitting a first SL-SSB;

determine a second resource based on a slot format of the first SL-SSB among the first resource; and

control the at least one transceiver to transmit the first SL-SSB to a second apparatus based on the second resource,

wherein the first resource is determined based on a starting symbol index and an ending symbol index in a slot for the first SL-SSB, and

wherein the second resource represents a resource that overlaps with an uplink (UL) resource or a sidelink (SL) resource based on the slot format among the first resource.

12. An apparatus controlling a first terminal, the apparatus including:

at least one processor; and

at least one computer memory operably coupled by the at least one processor and storing instructions,

wherein, by the at least one processor executing the instructions, the first terminal is configured to:

generate the SL-SSB including a sidelink primary synchronization signal (SPSS), a sidelink secondary synchronization signal (SSSS) and a sidelink physical broadcast channel (PSBCH);

determine a first resource capable of transmitting a first SL-SSB;

determine a second resource based on a slot format of the first SL-SSB among the first resource; and

transmit the first SL-SSB to a second apparatus based on the second resource,

wherein the first resource is determined based on a starting symbol index and an ending symbol index in a slot for the first SL-SSB, and

wherein the second resource represents a resource that overlaps with an uplink (UL) resource or a sidelink (SL) resource based on the slot format among the first resource.