Sidelink positioning based on PRS transmission of single user equipment in NR V2X

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

transmitting, to a plurality of second devices, at least one positioning reference signal (PRS);

receiving, from the plurality of second devices, location information of the plurality of second devices and time of arrival (TOA) values of the plurality of second devices; and

determining a location of the first device based on the location information of the plurality of second UEs and the TOA values of the plurality of second devices,

wherein the TOA values are determined based on the time when the plurality of second devices received the at least one PRS.

2. The method of claim 1 , further comprising:

transmitting a message requesting sidelink positioning to a plurality of devices; and

receiving at least one message accepting the sidelink positioning from the plurality of second devices among the plurality of devices.

3. The method of claim 2 , wherein the plurality of second devices include at least one of a second device in which a reference signal received power (RSRP) value measured based on a demodulation reference signal (DM-RS) on a physical sidelink control channel (PSCCH) or a DM-RS on a physical sidelink shared channel (PS SCH) through which the message requesting sidelink positioning is transmitted is greater than or equal to a pre-configured threshold value, a second device in which a reliability related to a location information of the second device is greater than or equal to a pre-configured threshold value, a second device having a channel busy ratio of the second device related to time when the message requesting sidelink positioning is received from the first device is lower than a pre-configured threshold value, or a second device having a channel occupancy ratio of the second device related to time when the message requesting sidelink positioning is received from the first device is lower than a pre-configured threshold value.

4. The method of claim 3 , wherein the pre-configured threshold value is determined differently based on a service related to sidelink positioning of the first device.

5. The method of claim 3 , wherein the pre-configured threshold value is configured by a base station or the first device.

6. The method of claim 2 , wherein retransmission for the at least one PRS is requested from the plurality of second devices to the first device, based on the TOA values not transmitted from the plurality of second devices to the first device within a pre-configured time, and

wherein the pre-configured time is determined based on services related to the plurality of second devices.

7. The method of claim 1 , further comprising:

transmitting a message requesting the plurality of second devices to transmit information related to capability of a second device; and

receiving the information related to the capability of the second device from the plurality of second devices,

wherein the message requesting the plurality of second devices to transmit information related to the capability of the second device includes information related to capability of the first device.

8. The method of claim 7 , further comprising:

determining a sidelink positioning method of the first device and a parameter for transmitting the at least one PRS based on the information related to the capability of the second device.

9. The method of claim 8 , further comprising:

determining assistance data based on the information related to the capability of the second device; and

transmitting, to the plurality of second devices, at least one sidelink positioning protocol message including the assistance data,

wherein the at least one sidelink positioning protocol message represents the sidelink positioning method by a transaction ID,

wherein the assistance data is divided and transmitted to the plurality of second devices, and

wherein a last transmitted sidelink positioning protocol message includes information related to an end for the transaction ID.

10. The method of claim 9 , wherein the at least one PRS is transmitted to the plurality of second devices based on the assistance data.

11. The method of claim 2 , wherein the message requesting the sidelink positioning includes priority information of a service related to the first device, and

wherein the plurality of second devices include a second device in which a priority of a service related to the second device is lower than a priority of a service related to the first device.

12. The method of claim 1 , wherein the at least one PRS is transmitted through any one of at least one S-SSB, at least one PSCCH or at least one PS SCH.

13. The method of claim 1 , wherein the location of the first device is determined based on the location information of the second device and at least one of a difference between the TOA values of the plurality of second devices or a sum of the TOA values of the plurality of second devices.

14. A first device for performing 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, to a plurality of second devices, at least one positioning reference signal (PRS);

receive, from the plurality of second devices, location information of the plurality of second devices and time of arrival (TOA) values of the plurality of second devices; and

determine a location of the first device based on the location information of the plurality of second devices and the TOA values of the plurality of second devices,

wherein the TOA values are determined based on the time when the plurality of second devices received the at least one PRS.

15. A device configured to control a first user equipment (UE), the device comprising:

one or more processors; and

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

transmit, to a plurality of second UEs, at least one positioning reference signal (PRS);

receive, from the plurality of second UEs, location information of the plurality of second devices and time of arrival (TOA) values of the plurality of second UEs; and

determine a location of the first device based on the location information of the plurality of second UEs and the TOA values of the plurality of second UEs,

wherein the TOA values are determined based on the time when the plurality of second UEs received the at least one PRS.