Methods and apparatuses for collision control of sidelink communications in wireless communication systems

1. A wireless communication device comprising:

one or more non-transitory computer-readable media having computer-executable instructions embodied thereon; and

at least one processor coupled to the one or more non-transitory computer-readable media, and configured to execute the computer-executable instructions to:

determine whether to transmit a first Sidelink Synchronization Signal (SLSS) according to a priority parameter when a channel carrying the first SLSS collides with a Physical Sidelink Feedback Channel (PSFCH) that carries Sidelink Feedback Control Information (SFCI); and

transmit the first SLSS in response to the priority parameter not corresponding to a higher priority than a priority of the SLSS,

wherein the priority parameter is associated with a data being carried on a Physical Sidelink Shared Channel (PSSCH) that corresponds to the PSFCH.

2. The wireless communication device of claim 1 , wherein the priority parameter is contained in Sidelink Control Information (SCI) carried on the PSSCH.

3. The wireless communication device of claim 1 , wherein the at least one processor is further configured to execute the computer-executable instructions to:

receive a first signal quality threshold and a second signal quality threshold;

determine whether to transmit a second SLSS based on the first signal quality threshold when the wireless communication device is engaged in a unicast operation; and

determine whether to transmit the second SLSS based on the second signal quality threshold when the wireless communication device is engaged in a groupcast operation.

4. The wireless communication device of claim 1 , wherein the at least one processor is further configured to execute the computer-executable instructions to:

obtain a plurality of SLSS transmission configurations when the wireless communication device belongs to a plurality of groups at a same time, wherein devices in a same group have a same group identity (ID); and

perform SLSS transmissions with the plurality of groups based on the plurality of SLSS transmission configurations.

5. The wireless communication device of claim 4 , wherein the plurality of SLSS transmission configurations includes a first SLSS transmission configuration and a second SLSS transmission configuration, and the first SLSS transmission configuration and the second SLSS transmission configuration are different from each other in at least one of:

a transmission power;

a time-domain SLSS resource allocation; and

a frequency-domain SLSS resource allocation.

6. The wireless communication device of claim 5 , wherein the plurality of groups includes a first group and a second group, and the at least one processor is further configured to execute the computer-executable instructions to:

perform a first SLSS transmission with the first group based on the first SLSS transmission configuration; and

perform a second SLSS transmission with the second group based on the second SLSS transmission configuration.

7. The wireless communication device of claim 4 , wherein an SLSS ID of the first SLSS is derived from a group ID of one of the plurality of groups that the wireless communication device belongs to.

8. The wireless communication device of claim 1 , wherein the wireless communication device is a scheduler source device in a group of wireless communication devices.

9. The wireless communication device of claim 1 , wherein the channel carrying the first SLSS is determined to be colliding with the PSFCH when an occasion of the first SLSS overlaps the PSFCH in at least one Orthogonal Frequency Division Multiplexing (OFDM) symbol in time domain.

10. The wireless communication device of claim 1 , wherein the channel carrying the first SLSS is determined to be colliding with the PSFCH when an occasion of the first SLSS overlaps the PSFCH in at least one resource element.

11. The wireless communication device of claim 1 , wherein the channel carrying the first SLSS is determined to be colliding with the PSFCH when at least part of the first SLSS and the PSFCH are configured to be transmitted through a plurality of spatial filters at a same time.

12. The wireless communication device of claim 1 , wherein the channel carrying the first SLSS and the PSFCH are configured on one of:

different Bandwidth Parts (BWPs);

different resource pools; and

different carriers.

13. The wireless communication device of claim 1 , wherein the first SLSS is one of a Long Term Evolution (LTE) SLSS, an LTE Physical Broadcast Channel (PBCH), a New Radio (NR) SLSS, an NR PBCH, and an NR Synchronization Signal/PBCH Block (SSB).

14. A method performed by a wireless communication device, the method comprising:

determining whether to transmit a first Sidelink Synchronization Signal (SLSS) according to a priority parameter when a channel carrying the first SLSS collides with a Physical Sidelink Feedback Channel (PSFCH) that carries Sidelink Feedback Control Information (SFCI); and

transmitting the first SLSS in response to the priority parameter not corresponding to a higher priority than a priority of the SLSS,

wherein the priority parameter is associated with a Physical Sidelink Shared Channel (PSSCH) that corresponds to the PSFCH.

15. The method of claim 14 , wherein the priority parameter is contained in Sidelink Control Information (SCI) carried on the PSSCH.

16. The method of claim 14 , further comprising:

receiving a first signal quality threshold and a second signal quality threshold;

determining whether to transmit a second SLSS based on the first signal quality threshold when the wireless communication device is engaged in a unicast operation; and

determining whether to transmit the second SLSS based on the second signal quality threshold when the wireless communication device is engaged in a groupcast operation.

17. The method of claim 14 , further comprising:

obtaining a plurality of SLSS transmission configurations when the wireless communication device belongs to a plurality of groups at a same time, wherein devices in a same group have a same group identity (ID); and

performing SLSS transmissions with the plurality of groups based on the plurality of SLSS transmission configurations.

18. The method of claim 17 , wherein the plurality of SLSS transmission configurations includes a first SLSS transmission configuration and a second SLSS transmission configuration, and the first SLSS transmission configuration and the second SLSS transmission configuration are different from each other in at least one of:

a transmission power;

a time-domain SLSS resource allocation; and

a frequency-domain SLSS resource allocation.

19. The method of claim 18 , wherein the plurality of groups includes a first group and a second group, and the method further comprises:

performing a first SLSS transmission with the first group based on the first SLSS transmission configuration; and

performing a second SLSS transmission with the second group based on the second SLSS transmission configuration.

20. The method of claim 17 , wherein an SLSS ID of the first SLSS is derived from a group ID of one of the plurality of groups that the wireless communication device belongs to.

21. The method of claim 14 , wherein the wireless communication device is a scheduler source device in a group of wireless communication devices.

22. The method of claim 14 , wherein the occasion of channel carrying the first SLSS is determined to be colliding with the PSFCH when an occasion of the first SLSS overlaps the PSFCH in at least one Orthogonal Frequency Division Multiplexing (OFDM) symbol in time domain.

23. The method of claim 14 , wherein the channel carrying the first SLSS is determined to be colliding with the PSFCH when an occasion of the first SLSS overlaps the PSFCH in at least one resource element.

24. The method of claim 14 , wherein the channel carrying the first SLSS is determined to be colliding with the PSFCH when at least part of the first SLSS and the PSFCH are configured to be transmitted through a plurality of spatial filters at a same time.

25. The method of claim 14 , wherein the channel carrying the first SLSS and the PSFCH are configured on one of:

different Bandwidth Parts (BWPs);

different resource pools; and

different carriers.

26. The method of claim 14 , wherein the first SLSS is one of a Long Term Evolution (LTE) SLSS, an LTE Physical Broadcast Channel (PBCH), a New Radio (NR) SLSS, an NR PBCH, and an NR Synchronization Signal/PBCH Block (SSB).