User equipment and resource selection method in sidelink communication

1 . A resource selection method in sidelink communication by a user equipment (UE), comprising:

being triggered in a first slot, by a periodic-based partial sensing initiation from a higher layer, to start a periodic-based partial sensing; and

performing the periodic-based partial sensing by monitoring second slots belonging to at least one periodic sensing occasion, wherein the at least one periodic sensing occasion corresponds by a resource reservation periodicity to a set of candidate slots on a first sidelink resource pool for a sidelink transmission, the first slot is earlier than the second slots in time domain, and the second slots are earlier than the set of candidate slots in the time domain;

wherein the UE initializes a set of resources containing candidate resources within the set of candidate slots;

wherein the UE is configured to receive a first sidelink control information (SCI) from another UE in the second slots belonging to the at least one periodic sensing occasion, the UE is configured to measure a first reference signal received power (RSRP) for the received first SCI during the periodic-based partial sensing, and when one or more resources from the candidate resources have been indicated/reserved by the first SCI and the associated first RSRP is higher than a first RSRP threshold, the UE excludes the one or more resources from the candidate resources;

wherein the UE reports a subset of resources from the first sidelink resource pool to the higher layer in a resource (re)selection trigger slot or after the resource (re)selection trigger slot but before a starting slot of the set of candidate slots, and the subset of resources comprises remaining candidate resources after exclusion.

2 . The method of claim 1 , wherein the sidelink transmission comprises at least one of a physical sidelink control channel (PSCCH) transmission or a physical sidelink shared channel (PSSCH) transmission.

3 . The method of claim 1 , wherein the UE performs the periodic-based partial sensing according to one or more of the followings:

the first sidelink resource pool from which a subset of resources is to be reported;

a layer 1 (L1) priority for the sidelink transmission;

a remaining packet delay budget (PDB) configured to determine a first resource selection window;

a number of sub-channels to be used for the sidelink transmission; or

at least one of the following: at least one resource reservation interval (P rsvp_TX ) for the sidelink transmission or at least one resource reservation interval (P rsvp_TX ) configured to determine the resource (re)selection trigger slot for the set of candidate slots.

4 . The method of claim 3 , wherein the set of candidate slots are selected by the UE within the first resource selection window based on the resource (re)selection trigger slot.

5 . The method of claim 3 , wherein the resource (re)selection trigger slot can be determined based on:

a location of the resource (re)selection trigger slot in the time domain equal to a location of the first slot in the time domain plus the at least one resource reservation interval (P rsvp_TX ) in the time domain indicated by the higher layer.

6 . The method of claim 1 , wherein the higher layer comprises a medium access control (MAC) layer on a UE side.

7 . A user equipment (UE), comprising:

a memory;

a transceiver; and

a processor coupled to the memory and the transceiver;

wherein the processor is configured to be triggered in a first slot, by a periodic-based partial sensing initiation from a higher layer, to start a periodic-based partial sensing; and

wherein the processor is configured to perform the periodic-based partial sensing by monitoring second slots belonging to at least one periodic sensing occasion, wherein the at least one periodic sensing occasion corresponds by a resource reservation periodicity to a set of candidate slots on a first sidelink resource pool for a sidelink transmission, the first slot is earlier than the second slots in time domain, and the second slots are earlier than the set of candidate slots in the time domain;

wherein the processor initializes a set of resources containing candidate resources within the set of candidate slots;

wherein the transceiver is configured to receive a first sidelink control information (SCI) from another UE in the second slots belonging to the at least one periodic sensing occasion, the processor is configured to measure a first reference signal received power (RSRP) for the received first SCI during the periodic-based partial sensing, and when one or more resources from the candidate resources have been indicated/reserved by the first SCI and the associated first RSRP is higher than a first RSRP threshold, the processor excludes the one or more resources from the candidate resources;

wherein the processor reports a subset of resources from the first sidelink resource pool to the higher layer in a resource (re)selection trigger slot or after the resource (re)selection trigger slot but before a starting slot of the set of candidate slots, and the subset of resources comprises remaining candidate resources after exclusion.

8 . The UE of claim 7 , wherein the sidelink transmission comprises at least one of a physical sidelink control channel (PSCCH) transmission or a physical sidelink shared channel (PSSCH) transmission.

9 . The UE of claim 7 , wherein the processor performs the periodic-based partial sensing according to one or more of the followings:

the first sidelink resource pool from which a subset of resources is to be reported;

a layer 1 (L1) priority for the sidelink transmission;

a remaining packet delay budget (PDB) configured to determine a first resource selection window;

a number of sub-channels to be used for the sidelink transmission; or

at least one of the following: at least one resource reservation interval (P rsvp_TX ) for the sidelink transmission or at least one resource reservation interval (P rsvp_TX ) configured to determine the resource (re)selection trigger slot for the set of candidate slots.

10 . The UE of claim 9 , wherein the set of candidate slots are selected by the processor within the first resource selection window based on the resource (re)selection trigger slot.

11 . The UE of claim 9 , wherein the resource (re)selection trigger slot can be determined based on:

a location of the resource (re)selection trigger slot in the time domain equal to a location of the first slot in the time domain plus the at least one resource reservation interval (P rsvp_TX ) in the time domain indicated by the higher layer.

12 . The UE of claim 7 , wherein the higher layer comprises a medium access control (MAC) layer on a UE side.

13 . A non-transitory machine-readable storage medium having stored thereon instructions that, when executed by a User Equipment (UE), cause the UE to perform a resource selection method comprising:

being triggered in a first slot, by a periodic-based partial sensing initiation from a higher layer, to start a periodic-based partial sensing; and

performing the periodic-based partial sensing by monitoring second slots belonging to at least one periodic sensing occasion, wherein the at least one periodic sensing occasion corresponds by a resource reservation periodicity to a set of candidate slots on a first sidelink resource pool for a sidelink transmission, the first slot is earlier than the second slots in time domain, and the second slots are earlier than the set of candidate slots in the time domain;

wherein the UE initializes a set of resources containing candidate resources within the set of candidate slots;

wherein the UE is configured to receive a first sidelink control information (SCI) from another UE in the second slots belonging to the at least one periodic sensing occasion, the UE is configured to measure a first reference signal received power (RSRP) for the received first SCI during the periodic-based partial sensing, and when one or more resources from the candidate resources have been indicated/reserved by the first SCI and the associated first RSRP is higher than a first RSRP threshold, the UE excludes the one or more resources from the candidate resources;

wherein the UE reports a subset of resources from the first sidelink resource pool to the higher layer in a resource (re)selection trigger slot or after the resource (re)selection trigger slot but before a starting slot of the set of candidate slots, and the subset of resources comprises remaining candidate resources after exclusion.

14 . The non-transitory machine-readable storage medium according to claim 13 , wherein the sidelink transmission comprises at least one of a physical sidelink control channel (PSCCH) transmission or a physical sidelink shared channel (PSSCH) transmission.