Method and apparatus for power saving in NR V2X
Provided are a method for performing wireless communication by a first device, and an apparatus for supporting same. The method may comprise: determining selectable candidate slots for sidelink (SL) transmission; determining N slots for sensing from a first slot among the selectable candidate slots, wherein the N slots are at least one slot for selecting at least one SL resource from among SL resources included in the selectable candidate slots; selecting the at least one SL resource based on the sensing for the N slots; and transmitting, to a second device through a physical sidelink shared channel (PSSCH), a medium access control protocol data unit (MAC PDU) based on the at least one SL resource, wherein a value of N is a positive integer.
1. A method for performing wireless communication by a first device, the method comprising:
triggering resource selection in a slot;
determining, based on the triggering, a time interval from the slot based on a remaining packet delay budget (PDB);
selecting a set of Y candidate slots within the time interval;
determining N slots for partial sensing before a first slot of the set of Y candidate slots;
performing the partial sensing for the N slots; and
selecting at least one sidelink (SL) resource based on the partial sensing for the N slots,
wherein a value of Y is a positive integer, and
wherein a value of N is a positive integer.
2. The method of claim 1 , wherein the N slots for the partial sensing are determined based on only the first slot of the set of Y candidate slots.
3. The method of claim 1 , wherein, based on that the resource selection is triggered by aperiodic transmission, the N slots for the partial sensing from the slot and before the first slot of the set of Y candidate slots are determined by the first device.
4. The method of claim 1 , wherein the at least one SL resource is selected from among candidate SL resources within the set of Y candidate slots.
5. The method of claim 4 , wherein a number of candidate SL resources is greater than or equal to X percent of a total number of candidate resources,
wherein a value of X is configured differently based on whether or not the first device is a device requiring power saving, and
wherein the value of X is a positive integer.
6. The method of claim 4 , wherein, based on a number of candidate SL resources being less than X percent of a total number of candidate resources, and the first device being a device requiring power saving, reference signal received power (RSRP) threshold boosting to secure the number of candidate SL resources greater than or equal to X percent of the total number of candidate resources is not allowed for the first device, and
wherein a value of X is a positive integer.
7. The method of claim 1 , further comprising:
transmitting, to a second device, sidelink control information (SCI) through a physical sidelink shared channel (PSSCH) based on the at least one SL resource.
8. The method of claim 7 , wherein, based on whether or not the first device is a device requiring power saving, a parameter for mapping the SCI on resources related to the PSSCH is configured differently.
9. The method of claim 7 , wherein, based on a resource selection method of the first device, a parameter for mapping the SCI on resources related to the PSSCH is configured differently, and
wherein the resource selection method includes random selection-based resource selection, partial sensing-based resource selection, or full sensing-based resource selection.
10. The method of claim 1 , further comprising:
transmitting a demodulation reference signal (DMRS).
11. The method of claim 10 , wherein, based on whether or not the first device is a device requiring power saving, candidate patterns for mapping the DMRS are configured differently.
12. The method of claim 10 , wherein, based on a resource selection method of the first device, candidate patterns for mapping the DMRS are configured differently, and
wherein the resource selection method includes random selection-based resource selection, partial sensing-based resource selection, or full sensing-based resource selection.
13. The method of claim 1 , wherein, based on whether or not the first device is a device requiring power saving, candidate modulation and coding scheme (MCS) tables are configured differently.
14. The method of claim 1 , wherein, based on a resource selection method of the first device, candidate modulation and coding scheme (MCS) tables are configured differently, and
wherein the resource selection method includes random selection-based resource selection, partial sensing-based resource selection, or full sensing-based resource selection.
15. A first device adapted to perform wireless communication, the first device comprising:
at least one transceiver;
at least one processor; and
at least one memory connected to the at least one processor and storing instructions that, based on being executed, cause the at least one processor to perform operations comprising:
triggering resource selection in a slot;
determining, based on the triggering, a time interval from the slot based on a remaining packet delay budget (PDB);
selecting a set of Y candidate slots within the time interval;
determining N slots for partial sensing before a first slot of the set of Y candidate slots;
performing the partial sensing for the N slots; and
selecting at least one sidelink (SL) resource based on the partial sensing for the N slots,
wherein a value of Y is a positive integer, and
wherein a value of N is a positive integer.
16. A processing device adapted to control a first device, the processing device comprising:
at least one processor; and
at least one memory connected to the at least one processor and storing instructions that, based on being executed, cause the at least one processor to perform operations comprising:
triggering resource selection in a slot;
determining, based on the triggering, a time interval from the slot based on a remaining packet delay budget (PDB);
selecting a set of Y candidate slots within the time interval;
determining N slots for partial sensing before a first slot of the set of Y candidate slots;
performing the partial sensing for the N slots; and
selecting at least one sidelink (SL) resource based on the partial sensing for the N slots,
wherein a value of Y is a positive integer, and
wherein a value of N is a positive integer.
17. The processing device of claim 16 , wherein the N slots for the partial sensing are determined based on only the first slot of the set of Y candidate slots.
18. The processing device of claim 16 , wherein, based on that the resource selection is triggered by aperiodic transmission, the N slots for the partial sensing from the slot and before the first slot of the set of Y candidate slots are determined by the first device.
19. The first device of claim 15 , wherein the N slots for the partial sensing are determined based on only the first slot of the set of Y candidate slots.
20. The first device of claim 15 , wherein, based on that the resource selection is triggered by aperiodic transmission, the N slots for the partial sensing from the slot and before the first slot of the set of Y candidate slots are determined by the first device.