Channel state information collection in physical sidelink channels

1. A method of wireless communication performed by a first user equipment (UE), the method comprising:

transmitting, to a second UE in a first time period, a resource reservation indicating resources associated with at least one channel state information reference signal (CSI-RS);

transmitting, to the second UE, the at least one CSI-RS in a second time period, wherein the second time period is at least K time periods after the first time period, wherein K is a positive integer, and wherein the time periods comprise at least one of slots or sub-slots;

receiving, from the second UE, a CSI report based on the at least one CSI-RS;

transmitting, to the second UE, a retransmission resource reservation indicating resources associated with a retransmission of a transport block (TB); and

transmitting, to the second UE, a resource reservation for at least one other CSI-RS overriding the retransmission resource reservation.

2. The method of claim 1 , wherein:

a value of K is based on a beam switching time associated with the second UE;

the beam switching time is based on radio frequency processing capabilities associated with the second UE; and

the method further comprises:

transmitting, to the second UE, a communication via a physical sidelink control channel (PSCCH), wherein the beam switching time is based on a subcarrier spacing associated with the PSCCH.

3. The method of claim 1 , further comprising:

transmitting, to the second UE, a plurality of CSI-RSs in a plurality of time periods; and

wherein:

each of the plurality of CSI-RSs corresponds to a respective beam;

the plurality of CSI-RSs includes the at least one CSI-RS; and

the plurality of time periods includes the second time period.

4. A method of wireless communication performed by a first user equipment (UE), the method comprising:

receiving, from a second UE in a first time period, a resource reservation indicating resources associated with at least one channel state information reference signal (CSI-RS);

receiving, from the second UE, the at least one CSI-RS in a second time period, wherein the second time period is at least K time periods after the first time period, wherein K is a positive integer, and wherein the time periods comprise at least one of slots or sub-slots;

transmitting, to the second UE, a CSI report based on the at least one CSI-RS;

receiving, from the second UE, a retransmission resource reservation indicating resources associated with a retransmission of a transport block (TB); and

receiving, from the second UE, a resource reservation for at least one other CSI-RS overriding the retransmission resource reservation.

5. The method of claim 4 , wherein:

a value of K is based on a beam switching time associated with the first UE;

the beam switching time is based on radio frequency processing capabilities associated with the first UE; and

further comprising:

receiving, from the second UE, a communication via a physical sidelink control channel (PSCCH), wherein the beam switching time is further based on a subcarrier spacing associated with the PSCCH.

6. A first user equipment (UE) comprising:

a memory;

a transceiver; and

at least one processor coupled to the memory and the transceiver, wherein the first UE is configured to:

transmit, to a second UE in a first time period, a resource reservation indicating resources associated with at least one channel state information reference signal (CSI-RS);

transmit, to the second UE, the at least one CSI-RS in a second time period, wherein the second time period is at least K time periods after the first time period, wherein K is a positive integer, and wherein the time periods comprise at least one of slots or sub-slots;

receive, from the second UE, a CSI report based on the at least one CSI-RS;

transmit, to the second UE, a retransmission resource reservation indicating resources associated with a retransmission of a transport block (TB); and

transmit, to the second UE, a resource reservation for at least one other CSI-RS overriding the retransmission resource reservation.

7. The first UE of claim 6 , wherein the first UE is further configured to:

transmit, to the second UE, a request for the CSI report in the first time period.

8. The first UE of claim 7 , wherein the first UE is further configured to:

transmit the request in sidelink control information (SCI); and

transmit the resource reservation in the SCI.

9. The first UE of claim 6 , wherein a value of K is based on a beam switching time associated with the second UE.

10. The first UE of claim 9 , wherein the beam switching time is based on radio frequency processing capabilities associated with the second UE.

11. The first UE of claim 9 , wherein the first UE is further configured to:

transmit, to the second UE, a communication via a physical sidelink control channel (PSCCH), wherein the beam switching time is based on a subcarrier spacing associated with the PSCCH.

12. The first UE of claim 6 , wherein the first UE is further configured to:

transmit, to the second UE, a plurality of CSI-RSs in a plurality of time periods, wherein:

each of the plurality of CSI-RSs corresponds to a respective beam;

the plurality of CSI-RSs includes the at least one CSI-RS; and

the plurality of time periods includes the second time period.

13. The first UE of claim 6 , wherein the first UE is further configured to:

receive the CSI report in a medium access control (MAC) control element.

14. The first UE of claim 6 , wherein the first UE is further configured to:

transmit, to the second UE, a transport block (TB), wherein the resource reservation further indicates resources reserved for a retransmission of the TB.

15. The first UE of claim 6 , wherein the first UE is further configured to:

refrain from transmitting a physical sidelink shared channel in the second time period.

16. The first UE of claim 6 , wherein the first UE is further configured to:

transmit, to the second UE, the TB; and

receive, from the second UE, an acknowledgement indicating successful decoding of the TB.

17. The first UE of claim 6 , wherein the first UE is further configured to:

transmit, to the second UE, a plurality of CSI-RSs, the plurality of CSI-RSs including the at least one CSI-RS; and

transmit, to the second UE, an automatic gain control symbol before each of the plurality of CSI-RSs.

18. The first UE of claim 6 , wherein:

the first time period is at least one of a first slot or a first sub-slot; and

the second time period is at least one of a second slot or a second sub-slot.

19. The first UE of claim 6 , wherein the first UE is further configured to:

transmit the resource reservation indicating periodic resources associated with the at least one CSI-RS.

20. The first UE of claim 19 , wherein the first UE is further configured to:

transmit a codepoint in sidelink control information (SCI) that indicates a period associated with the periodic resources.

21. The first UE of claim 6 , wherein the first UE is further configured to:

transmit, to the second UE, sidelink control information (SCI) indicating a request for a plurality of CSI reports, wherein the plurality of CSI reports includes the CSI report; and

receive, from the second UE, the plurality of CSI reports based on the at least one CSI-RS.

22. The first UE of claim 6 , wherein the first UE is further configured to:

transmit the resource reservation in a configured grant (CG) carried by a radio resource control (RRC) signal.

23. The first UE of claim 22 , wherein:

the CG comprises a CSI resource reservation indicating resources associated with the CSI report; and

the first UE is further configured to:

receive the CSI report periodically based on the CSI resource reservation.

24. The first UE of claim 6 , wherein the first UE is further configured to:

transmit, to a base station (BS), a request for the resource reservation; and

receive, from the BS, an indicator indicating the resources associated with the at least one CSI-RS.

25. A first user equipment (UE) comprising:

a memory;

a transceiver; and

at least one processor coupled to the memory and the transceiver, wherein the first UE is configured to:

receive, from a second UE in a first time period, a resource reservation indicating resources associated with at least one channel state information reference signal (CSI-RS);

receive, from the second UE, the at least one CSI-RS in a second time period, wherein the second time period is at least K time periods after the first time period, wherein K is a positive integer, and wherein the time periods comprise at least one of slots or sub-slots;

transmit, to the second UE, a CSI report based on the at least one CSI-RS;

receive, from the second UE, a retransmission resource reservation indicating resources associated with a retransmission of a transport block (TB); and

receive, from the second UE, a resource reservation for at least one other CSI-RS overriding the retransmission resource reservation.

26. The first UE of claim 25 , wherein the first UE is further configured to:

receive, from the second UE, a request for the CSI report in the first time period in sidelink control information (SCI); and

receive the resource reservation in the SCI.

27. The first UE of claim 25 , wherein

a value of K is based on a beam switching time associated with the first UE;

the beam switching time is based on radio frequency processing capabilities associated with the first UE; and

the first UE is further configured to:

receive, from the second UE, a communication via a physical sidelink control channel (PSCCH), wherein the beam switching time is further based on a subcarrier spacing associated with the PSCCH.

28. The first UE of claim 25 , wherein the first UE is further configured to:

receive, from the second UE, a plurality of CSI-RSs in a plurality of time periods, wherein:

each of the plurality of CSI-RSs corresponds to a beam; and

the plurality of CSI-RSs includes the at least one CSI-RS.

29. The first UE of claim 25 , wherein the first UE is further configured to:

receive, from the second UE, the TB; and

transmit, to the second UE, an acknowledgement indicating successful decoding of the TB.

30. The first UE of claim 25 , wherein the first UE is further configured to:

receive the resource reservation indicating periodic resources associated with the at least one CSI-RS; and

receive the resource reservation in a configured grant (CG) carried by a radio resource control (RRC) signal.