Method and apparatus for sidelink CSI acquisition

1. A user equipment (UE) comprising:

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

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

receive a first sidelink (SL) control information (SCI) format from another UE, the first SCI format including resource allocation information of a second SCI format different from the first SCI format;

receive the second SCI format from the another UE based on the first SCI format, the second SCI format including a channel state information (C SI) request field and a source identifier (ID) field corresponding to the another UE; and

generate a CSI report triggered by receiving the second SCI format.

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

receive an SL reference signal (RS) configuration for SL CSI measurement, the SL RS configuration including at least one of a channel state information reference signal (CSI-RS), a sounding reference signal (SRS), an automatic gain control (AGC) training RS, and a demodulation reference signal (DM-RS).

3. The UE of claim 2 , wherein the SL RS configuration is received via SL radio resource control (RRC) signaling from the another UE.

4. The UE of claim 2 , wherein a period of the CSI-RS is the same as a period of a physical SL control channel (PSCCH) transmission.

5. The UE of claim 2 , wherein the at least one processor is further configured to execute the computer-executable instructions to:

perform the SL CSI measurement at a first time based on the SL RS configuration to generate the CSI report;

perform sensing to obtain a radio resource for transmitting the CSI report, the radio resource allocated at a second time; and

drop the CSI report when a time difference between the first time and the second time is greater than a threshold.

6. The UE of claim 2 , wherein the CSI report includes at least one of a bandwidth part (BWP) identifier (ID), a carrier ID, and a resource pool ID based on the SL RS configuration.

7. The UE of claim 1 , wherein the second SCI format further includes resource allocation information for transmitting the CSI report.

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

determine an SL channel condition; and

transmit the CSI report to the another UE when the SL channel condition has a quality value that is greater than a threshold quality value.

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

determine the SL channel condition based on at least one of an SL reference signal received power (SL-RSRP), an SL signal to interference plus noise ratio (SL-SINR), a channel busy ratio (CBR), and a channel occupancy ratio (CR).

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

transmit a third SCI format to the another UE, the third SCI format including a CSI indication field and resource allocation information of a first physical SL shared channel (PSSCH) transmission, the CSI indication field indicating that the first PSSCH transmission includes the CSI report.

11. The UE of claim 10 , wherein the second SCI format further includes resource allocation information of a second PSSCH transmission, and the at least one processor is further configured to execute the computer-executable instructions to:

transmit the CSI report to the another UE in the second PSSCH transmission when the CSI request field indicates that the CSI report is triggered; and

receive data from the another UE in the second PSSCH transmission when the CSI request field indicates that the CSI report is not triggered.

12. A method for sidelink (SL) channel state information (CSI) acquisition performed by a user equipment (UE), the method comprising:

receiving a first SL control information (SCI) format from another UE, the first SCI format including resource allocation information of a second SCI format different from the first SCI format;

receiving the second SCI format from the another UE based on the first SCI format, the second SCI format including a channel state information (C SI) request field and a source identifier (ID) field corresponding to the another UE; and

generating a CSI report triggered by receiving the second SCI format.

13. The method of claim 12 , further comprising:

receiving an SL reference signal (RS) configuration for SL CSI measurement, the SL RS configuration including at least one of a channel state information reference signal (CSI-RS), a sounding reference signal (SRS), an automatic gain control (AGC) training RS, and a demodulation reference signal (DM-RS).

14. The method of claim 13 , wherein the SL RS configuration is received via SL radio resource control (RRC) signaling from the another UE.

15. The method of claim 13 , wherein a period of the CSI-RS is the same as a period of a physical SL control channel (PSCCH) transmission.

16. The method of claim 13 , further comprising:

performing the SL CSI measurement at a first time based on the SL RS configuration to generate the CSI report;

performing sensing to obtain a radio resource for transmitting the CSI report, the radio resource allocated at a second time; and

dropping the CSI report when a time difference between the first time and the second time is greater than a threshold.

17. The method of claim 12 , wherein the second SCI format further includes resource allocation information for transmitting the CSI report.

18. The method of claim 12 , further comprising:

determining an SL channel condition; and

transmitting the CSI report to the another UE when the SL channel condition has a quality value that is greater than a threshold quality value.

19. The method of claim 12 , further comprising:

transmitting a third SCI format to the another UE, the third SCI format including a CSI indication field and resource allocation information of a first physical SL shared channel (PSSCH) transmission, the CSI indication field indicating that the first PSSCH transmission includes the CSI report.

20. The method of claim 19 , wherein the second SCI format further includes resource allocation information of a second PSSCH transmission, and the method further comprising:

transmitting the CSI report to the another UE in the second PSSCH transmission when the CSI request field indicates that the CSI report is triggered; and

receiving data from the another UE in the second PSSCH transmission when the CSI request field indicates that the CSI report is not triggered.