Method and apparatus for performing sidelink communication in wireless communication systems

1. A user equipment (UE) 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:

receive a Radio Resource Control (RRC) configuration for configuring the UE with a plurality of types of Demodulation Reference Signal (DMRS) patterns;

receive a Sidelink Control Information (SCI) message comprising DMRS-related information, the DMRS-related information indicating one of the plurality of types of DMRS patterns; and

perform a Physical Sidelink Shared Channel (PSSCH) transmission according to the one of the plurality of types of DMRS patterns indicated by the SCI message.

2. The UE of claim 1 , wherein the SCI message further comprises Tracking Reference Signal (TRS) related information which includes at least one of:

a TRS exist indicator for indicating whether a TRS is transmitted in a sidelink (SL) physical channel,

TRS sequence generation information,

a TRS port index, and

a TRS pattern.

3. The UE of claim 1 , wherein the SCI message further comprises Phase Tracking Reference Signal (PTRS) related information which includes at least one of:

a PTRS exist indicator for indicating whether a PTRS is transmitted in a sidelink (SL) physical channel,

PTRS sequence generation information,

a PTRS port index, and

a PTRS pattern.

4. The UE of claim 1 , wherein the SCI message further comprises channel repetition information which indicates at least one of:

a number of repetitions of a sidelink (SL) physical channel,

a time gap between two adjacent repetitions of the SL physical channel, and

a spatial domain filter for receiving at least one repetition of the SL physical channel.

5. The UE of claim 4 , wherein the SL physical channel is one of a PSSCH and a Physical Sidelink Control Channel (PSCCH).

6. The UE of claim 1 , wherein the at least one processor is further configured to execute the computer-executable instructions to:

obtain a resource pool configuration which is contained in a pre-configuration parameter or configured by a base station,

wherein the resource pool configuration indicates a number of repetitions of an SL physical channel.

7. The UE of claim 1 , wherein the at least one processor is further configured to execute the computer-executable instructions to:

obtain a particular indicator which is contained in a pre-configuration parameter or configured by a base station, wherein the particular indicator is used for indicating to the UE whether to transmit a plurality of Synchronization Signal Blocks (SSBs) in a synchronization signal periodicity.

8. The UE of claim 1 , wherein the at least one processor is further configured to execute the computer-executable instructions to:

obtain a mapping table which is contained in a pre-configuration parameter or configured by a base station, wherein the mapping table is used for indicating where a Synchronization Signal Blocks (SSB) is transmitted in a synchronization signal periodicity.

9. The UE of claim 1 , wherein the at least one processor is further configured to execute the computer-executable instructions to:

obtain a beam operation indicator contained in a resource pool configuration which is contained in a pre-configuration parameter or configured by a base station; and

determine, based on the beam operation indicator, whether to perform a multiple beam operation on a resource pool associated with the resource pool configuration,

wherein the multiple beam operation includes determining that a spatial-domain-filter-related Information Element (IE) is contained in the SCI message.

10. The UE of claim 1 , wherein the at least one processor is further configured to execute the computer-executable instructions to:

determine whether to perform a multiple beam operation on a resource pool based on a frequency range of an anchor carrier of the resource pool.

11. The UE of claim 1 , wherein the SCI message further comprises a Modulation and Coding Scheme (MCS) table indicator, and the at least one processor is further configured to execute the computer-executable instructions to:

perform modulation and coding for an SL physical channel based on a first MCS table when the MCS table indicator is set to a first value; and

perform modulation and coding for the SL physical channel based on a second MCS table when the MCS table indicator is set to a second value.

12. A method performed by a user equipment (UE), the method comprising:

receiving a Radio Resource Control (RRC) configuration for configuring the UE with a plurality of types of Demodulation Reference Signal (DMRS) patterns;

receiving a Sidelink Control Information (SCI) message comprising DMRS-related information, the DMRS-related information indicating one of the plurality of types of DMRS patterns; and

performing a Physical Sidelink Shared Channel (PSSCH) transmission according to the one of the plurality of types of DMRS patterns indicated by the SCI message.

13. The method of claim 12 , wherein the SCI message further comprises Tracking Reference Signal (TRS) related information which includes at least one of:

a TRS exist indicator for indicating whether a TRS is transmitted in a sidelink (SL) physical channel,

TRS sequence generation information,

a TRS port index, and

a TRS pattern.

14. The method of claim 12 , wherein the SCI message further comprises Phase Tracking Reference Signal (PTRS) related information which includes at least one of:

a PTRS exist indicator for indicating whether a PTRS is transmitted in a sidelink (SL) physical channel,

PTRS sequence generation information,

a PTRS port index, and

a PTRS pattern.

15. The method of claim 12 , wherein the SCI message further comprises channel repetition information which indicates at least one of:

a number of repetitions of a sidelink (SL) physical channel,

a time gap between two adjacent repetitions of the SL physical channel, and

a spatial domain filter for receiving at least one repetition of the SL physical channel.

16. The method of claim 15 , wherein the SL physical channel is one of a PSSCH and a Physical Sidelink Control Channel (PSCCH).

17. The method of claim 12 , further comprising:

obtaining a resource pool configuration which is contained in a pre-configuration parameter or configured by a base station,

wherein the resource pool configuration indicates a number of repetitions of a sidelink (SL) physical channel.

18. The method of claim 12 , further comprising:

obtaining a particular indicator which is contained in a pre-configuration parameter or configured by a base station, wherein the particular indicator is used for indicating to the UE whether to transmit a plurality of Synchronization Signal Blocks (SSBs) in a synchronization signal periodicity.

19. The method of claim 12 , further comprising:

obtaining a mapping table which is contained in a pre-configuration parameter or configured by a base station, wherein the mapping table is used for indicating where a Synchronization Signal Block (SSB) is transmitted in a synchronization signal periodicity.

20. The method of claim 12 , further comprising:

obtaining a beam operation indicator contained in a resource pool configuration which is contained in a pre-configuration parameter or configured by a base station; and

determining, based on the beam operation indicator, whether to perform a multiple beam operation on a resource pool associated with the resource pool configuration,

wherein the multiple beam operation includes determining that a spatial-domain-filter-related Information Element (IE) is contained in the SCI message.

21. The method of claim 12 , further comprising:

determining whether to perform a multiple beam operation on a resource pool based on a frequency range of an anchor carrier of the resource pool.

22. The method of claim 12 , wherein the SCI message further comprises a Modulation and Coding Scheme (MCS) table indicator, and the method further comprises:

performing modulation and coding for a sidelink (SL) physical channel based on a first MCS table when the MCS table indicator is set to a first value; and

performing modulation and coding for the SL physical channel based on a second MCS table when the MCS table indicator is set to a second value.