Multiplexing of CSI with SL-SCH for sidelink communications

1. A method of wireless communication, comprising:

transmitting, by a network entity to a user equipment (UE), a first sidelink control message (CCH-1), wherein the CCH-1 includes at least control information that indicates a resource allocation of data and decoding information for decoding a second sidelink control message (CCH-2);

transmitting, by the network entity to the UE, the CCH-2, wherein the CCH-2 includes one or more of control information for decoding data and is configured to include one or more channel state information (CSI) reports;

wherein the CCH-1 includes an indication of at least one of a presence or an absence of the one or more CSI reports included in the CCH-2; and

transmitting, by the network entity to the UE, the data based on the CCH-1 and the CCH-2.

2. The method of claim 1 , wherein the indication indicates the presence of the one or more CSI reports included in the CCH-2.

3. The method of claim 1 , wherein the indication of the at least one of the presence or the absence of the one or more CSI reports comprises an alternative CCH-2 control message format.

4. The method of claim 3 , wherein the alternative CCH-2 control message format corresponds to at least one of a first CCH-2 message format used for a unicast sidelink transmission based on the CCH-1 indicating the absence of the one or more CSI reports or a second CCH-2 message format used for the unicast sidelink transmission based on the CCH-1 indicating the presence of the one or more CSI reports.

5. The method of claim 1 , wherein the one or more CSI reports include one or more channel quality indicator (CQI), rank indicator (RI), pre-coding matrix indicator (PMI), and sidelink-reference signal received power (SL-RSRP).

6. The method of claim 1 , wherein the one or more CSI reports include information corresponding to channel state information-reference signal (CSI-RS) resources determined based on at least one CSI.

7. The method of claim 1 , further comprising:

determining whether the one or more CSI reports are included in the CCH-2; and

selecting a modulation code scheme (MCS) of the CCH-2 based at least on a determination of whether the one or more CSI reports are included in the CCH-2.

8. The method of claim 7 , further comprising selecting a scaling value based on the determination of whether the one or more CSI reports are included in the CCH-2.

9. The method of claim 1 , wherein transmitting the CCH-2 further comprises transmitting the CCH-2 including the one or more CSI reports without sidelink-synchronization channel (SL-SCH).

10. The method of claim 9 , further comprising setting a first priority of transmission of the CCH-2 to be a same priority as a second priority of transmission of a channel state information-reference signal (CSI-RS) corresponding to a peer UE transmission that included the CSI-RS.

11. The method of claim 9 , further comprising setting a first packet delay budget (PDB) of the transmission of the CCH-2 to be a same PDB as a second PDB of transmission of a channel state information-reference signal (CSI-RS) corresponding to a peer UE transmission that included the CSI-RS.

12. The method of claim 9 , wherein at least one of the CCH-1 and the CCH-2 indicate either that no hybrid automatic repeat request (HARQ) feedback is expected for transmitting the CCH-2 including the one or more CSI reports without the SL-SCH or that an acknowledgement (ACK) signal is expected for a successful decode of the CCH-2.

13. The method of claim 9 , further comprising determining a number of resource elements for transmitting the CCH-2 based on a specified coding rate and a specified modulation order for transmitting the data and a scaling offset factor.

14. The method of claim 9 , further comprising determining a number of resource elements for transmitting the CCH-2 based on a specified coding rate and a specified modulation order for transmitting the CCH-2.

15. The method of claim 1 , wherein transmitting the data comprises transmitting a sidelink physical shared channel (PSSCH) that carries at least a sidelink shared channel (SL-SCH).

16. A method of wireless communication, comprising:

receiving, by a user equipment (UE) from a network entity, a first sidelink control message (CCH-1), wherein the CCH-1 includes at least control information that indicates a resource allocation of data and decoding information for decoding a second sidelink control message (CCH-2);

receiving, by the UE from the network entity, the CCH-2, wherein the CCH-2 includes one or more of control information for decoding data and is configured to include one or more channel state information (CSI) reports;

wherein the CCH-1 includes an indication of at least one of a presence or an absence of the one or more CSI reports included in the CCH-2; and

receiving, by the UE from the network entity, the data based on the CCH-1 and the CCH-2.

17. The method of claim 16 , wherein the indication indicates the presence of the one or more CSI reports included in the CCH-2.

18. The method of claim 16 , wherein the indication of the at least one of the presence or the absence of the one or more CSI reports comprises an alternative CCH-2 control message format.

19. The method of claim 18 , wherein the alternative CCH-2 control message format corresponds to at least one of a first CCH-2 message format used for a unicast sidelink transmission based on the CCH-1 indicating the absence of the one or more CSI reports or a second CCH-2 message format used for the unicast sidelink transmission based on the CCH-1 indicating the presence of the one or more CSI reports.

20. The method of claim 18 , wherein the CCH-1 indicates a number of the one or more CSI reports present in the CCH-2.

21. The method of claim 16 , wherein the one or more CSI reports include one or more channel quality indicator (CQI), rank indicator (RI), pre-coding matrix indicator (PMI), and sidelink-reference signal received power (SL-RSRP).

22. The method of claim 16 , wherein the one or more CSI reports include information corresponding to channel state information-reference signal (CSI-RS) resources determined based on at least one CSI.

23. The method of claim 16 , wherein receiving the CCH-2 further comprises receiving the CCH-2 including the one or more CSI reports without sidelink-synchronization channel (SL-SCH).

24. The method of claim 23 , wherein receiving the CCH-2 including the one or more CSI reports without the SL-SCH further comprises receiving the CCH-2 including the one or more CSI reports without the SL-SCH based on at least one of a priority of a transmission that included a channel state information-reference signal (CSI-RS) exceeding a priority threshold, a time delay from a reception of the CSI-RS exceeding a configured time slot threshold and a condition where there was no SL-SCH transmission opportunity during the time delay, or if a transmitter indicates to transmit at least one CSI without the SL-SCH.

25. The method of claim 24 , wherein the priority of the transmission that included the CSI-RS is indicated in the CCH-1.

26. The method of claim 23 , wherein at least one of the CCH-1 and the CCH-2 indicate that at least no hybrid automatic repeat request (HARQ) feedback is expected for transmitting the CCH-2 including the one or more CSI reports without the SL-SCH or an acknowledgement (ACK) signal is expected for a successful decode of the CCH-2.

27. The method of claim 23 , wherein a transmission size is fixed to a subchannel and a time slot, and wherein a size of the subchannel is configured for a resource pool used for transmitting the CCH-2 including the one or more CSI reports without the SL-SCH.

28. The method of claim 16 , wherein receiving the data comprises receiving a sidelink physical shared channel (PSSCH) that carries at least a sidelink shared channel (SL-SCH).

29. An apparatus for communication, comprising:

a memory configured to store instructions; and

one or more processors communicatively coupled with the memory, wherein the one or more processors are configured to:

transmit, by a network entity to a user equipment (UE), a first sidelink control message (CCH-1), wherein the CCH-1 includes at least control information that indicates a resource allocation of data and decoding information for decoding a second sidelink control message (CCH-2);

transmit, by the network entity to the UE, the CCH-2, wherein the CCH-2 includes one or more of control information for decoding data and is configured to include one or more channel state information (CSI) reports;

wherein the CCH-1 includes an indication of at least one of a presence or an absence of the one or more CSI reports included in the CCH-2; and

transmit, by the network entity to the UE, the data based on the CCH-1 and the CCH-2.

30. An apparatus for communication, comprising:

a memory configured to store instructions; and

one or more processors communicatively coupled with the memory, wherein the one or more processors are configured to:

receive, by a user equipment (UE) from a network entity, a first sidelink control message (CCH-1), wherein the CCH-1 includes at least control information that indicates a resource allocation of data and decoding information for decoding a second sidelink control message (CCH-2);

receive, by the UE from the network entity, the CCH-2, wherein the CCH-2 includes one or more of control information for decoding data and is configured to include one or more channel state information (CSI) reports;

wherein the CCH-1 includes an indication of at least one of a presence or an absence of the one or more CSI reports included in the CCH-2; and

receive, by the UE from the network entity, the data based on the CCH-1 and the CCH-2.