Hybrid automatic repeat request (HARQ) codebook enhancement and physical uplink control channel (PUCCH) resource determination with sidelink feedback forwarding

1. A method for wireless communications at by a first user equipment (UE), comprising:

receiving, from a network entity, a downlink control information (DCI) that schedules resources for at least one physical sidelink shared channel (PSSCH) transmission from the first UE to a second UE;

transmitting data to the second UE via the at least one PSSCH transmission using via the scheduled resources;

receiving, from the second UE, an acknowledgment feedback for the at least one PSSCH transmission in a first slot associated with a first feedback timing value, wherein the first feedback timing value indicates a first number of slots between reception of the acknowledgment feedback and transmission of the acknowledgment feedback;

receiving at least one downlink transmission from the network entity in a second slot associated with a second feedback timing value, wherein the second feedback timing value indicates a second number of slots between reception of the at least one downlink transmission and transmission of a feedback for the at least one downlink transmission, and wherein different feedback timing values associated with the first slot and the second slot correspond to a third slot;

selecting at least one codebook entry for providing the feedback for the at least one downlink transmission and the acknowledgment feedback for the at least one PSSCH transmission in the third slot; and

transmitting the at least one codebook entry to the network entity via at least one physical uplink control channel (PUCCH) transmission in the third slot.

2. The method of claim 1 , further comprising:

selecting a first codebook entry for providing the feedback for the at least one downlink transmission from the network entity to the first UE;

selecting a second codebook entry for acknowledging the at least one PSSCH transmission;

transmitting the first codebook entry via a first PUCCH transmission; and

transmitting the second codebook entry via a second PUCCH transmission.

3. The method of claim 1 , further comprising:

determining that the feedback for the at least one downlink transmission from the network entity to the first UE and the acknowledgment feedback for the at least one PSSCH transmission are scheduled in the third slot; and

providing a joint feedback via a single codebook entry based on the determination.

4. The method of claim 3 , further comprising selecting the single codebook entry from a type 1 or a type 2 hybrid automatic repeat request (HARQ) acknowledgement codebook.

5. The method of claim 3 , wherein the single codebook entry comprises:

a first set of one or more bits for acknowledging the at least one downlink transmission; and

a second set of one or more bits for acknowledging the at least one PSSCH transmission.

6. The method of claim 5 , wherein the first set of bits are concatenated with the second set of bits.

7. The method of claim 6 , wherein:

bits in the first set correspond to one or more physical downlink shared channel (PDSCH) occasions in an order in which the one or more PDSCH occasions were scheduled; and

bits in the second set correspond to one or more PSSCH occasions in an order in which the one or more PSSCH occasions were scheduled.

8. The method of claim 5 , wherein bits in the first set and the second set are interlaced.

9. The method of claim 8 , wherein:

each bit in the first set corresponds to a physical downlink shared channel (PDSCH) occasion;

each bit in the second set corresponds to a PSSCH occasion; and

each bit occurs in the single codebook entry in an order in which its corresponding PDSCH or PSSCH occasion was scheduled.

10. The method of claim 5 , wherein:

each bit in the first set corresponds to a physical downlink shared channel (PDSCH) occasion;

each bit in the second set corresponds to a PSSCH occasion; and

each bit occurs in the single codebook entry in an order in which their corresponding PDSCH or PSSCH occasion was scheduled.

11. The method of claim 1 , further comprising determining resources, within the third slot, for the at least one PUCCH transmission according to a rule.

12. The method of claim 11 , further comprising selecting the resources for the at least one PUCCH transmission based on a last feedback resource indicated via the DCI that scheduled resources for the at least one PSSCH transmission according to the rule.

13. The method of claim 11 , further comprising selecting the resources for the at least one PUCCH transmission based on a last feedback resource indicated via another DCI that scheduled the at least one downlink transmission from the network entity to the first UE according to the rule.

14. The method of claim 11 , further comprising selecting the resources for the at least one PUCCH transmission based on a last feedback resource indicated via a latest received one of another DCI that scheduled the at least one downlink transmission from the network entity to the first UE and the DCI that scheduled resources for the at least one PSSCH transmission according to the rule.

15. A An apparatus for wireless communications at a first user equipment (UE), comprising:

one or more memories comprising instructions; and

one or more processors configured to execute the instructions and cause the apparatus to:

receive, from a network entity, a downlink control information (DCI) that schedules resources for at least one physical sidelink shared channel (PSSCH) transmission from the first UE to a second UE;

transmit data to the second UE via the at least one PSSCH transmission using the scheduled resources;

receive, from the second UE, an acknowledgment feedback for the at least one PSSCH transmission in a first slot associated with a first feedback timing value, wherein the first feedback timing value indicates a first number of slots between reception of the acknowledgment feedback and transmission of the acknowledgment feedback;

receive at least one downlink transmission from the network entity in a second slot associated with a second feedback timing value, wherein the second feedback timing value indicates a second number of slots between reception of the at least one downlink transmission and transmission of a feedback for the at least one downlink transmission, and wherein different feedback timing values associated with the first slot and the second slot correspond to a third slot;

select at least one codebook entry for providing the feedback for the at least one downlink transmission and the acknowledgment feedback for the at least one PSSCH transmission in the third slot; and

transmit the at least one codebook entry to the network entity via at least one physical uplink control channel (PUCCH) transmission in the third slot.

16. The apparatus of claim 15 , wherein the one or more processors are configured to execute the instructions and cause the apparatus to:

select a first codebook entry for providing the feedback for the at least one downlink transmission from the network entity to the first UE;

select a second codebook entry for acknowledging the at least one PSSCH transmission;

transmit the first codebook entry via a first PUCCH transmission; and

transmit the second codebook entry via a second PUCCH transmission.

17. The apparatus of claim 15 , wherein the one or more processors are configured to execute the instructions and cause the apparatus to:

determine that the feedback for the at least one downlink transmission from the network entity to the first UE and the acknowledgment feedback for the at least one PSSCH transmission are scheduled in the third slot; and

provide a joint feedback via a single codebook entry based on the determination.

18. The apparatus of claim 17 , wherein the one or more processors are configured to execute the instructions and cause the apparatus to select the single codebook entry from a type 1 or a type 2 hybrid automatic repeat request (HARQ) acknowledgement codebook.

19. The apparatus of claim 17 , wherein the single codebook entry comprises:

a first set of one or more bits for acknowledging the at least one downlink transmission; and

a second set of one or more bits for acknowledging the at least one PSSCH transmission.

20. The apparatus of claim 19 , wherein the first set of bits are concatenated with the second set of bits.

21. The apparatus of claim 20 , wherein:

bits in the first set correspond to one or more physical downlink shared channel (PDSCH) occasions in an order in which the one or more PDSCH occasions were scheduled; and

bits in the second set correspond to one or more PSSCH occasions in an order in which the one or more PSSCH occasions were scheduled.

22. The apparatus of claim 19 , wherein bits in the first set and the second set are interlaced.

23. The apparatus of claim 22 , wherein:

each bit in the first set corresponds to a physical downlink shared channel (PDSCH) occasion;

each bit in the second set corresponds to a PSSCH occasion; and

each bit occurs in the single codebook entry in an order in which its corresponding PDSCH or PSSCH occasion was scheduled.

24. The apparatus of claim 15 , wherein the one or more processors are configured to execute the instructions and cause the apparatus to determine resources, within the third slot, for the at least one PUCCH transmission according to a rule.

25. The apparatus of claim 24 , wherein the one or more processors are configured to execute the instructions and cause the apparatus to select the resources for the at least one PUCCH transmission based on a last feedback resource indicated via the DCI that scheduled resources for the at least one PSSCH transmission according to the rule.

26. The apparatus of claim 24 , wherein the one or more processors are configured to execute the instructions and cause the apparatus to select the resources for the at least one PUCCH transmission based on a last feedback resource indicated via another DCI that scheduled the at least one downlink transmission from the network entity to the first UE according to the rule.

27. The apparatus of claim 24 , wherein the one or more processors are configured to execute the instructions and cause the apparatus to select the resources for the at least one PUCCH transmission based on a last feedback resource indicated via a latest received one of another DCI that scheduled the at least one downlink transmission from the network entity to the first UE and the DCI that scheduled resources for the at least one PSSCH transmission according to the rule.

28. A non-transitory computer-readable medium comprising computer-executable instructions that, when executed by one or more processors of a first user equipment (UE), cause the first UE to perform a method of wireless communications, comprising:

receiving, from a network entity, a downlink control information (DCI) that schedules resources for at least one physical sidelink shared channel (PSSCH) transmission from the first UE to a second UE;

transmitting data to the second UE via the at least one PSSCH transmission using the scheduled resources;

receiving, from the second UE, an acknowledgment feedback for the at least one PSSCH transmission in a first slot associated with a first feedback timing value, wherein the first feedback timing value indicates a first number of slots between reception of the acknowledgment feedback and transmission of the acknowledgment feedback;

receiving at least one downlink transmission from the network entity in a second slot associated with a second feedback timing value, wherein the second feedback timing value indicates a second number of slots between reception of the at least one downlink transmission and transmission of a feedback for the at least one downlink transmission, and wherein different feedback timing values associated with the first slot and the second slot correspond to a third slot;

selecting at least one codebook entry for providing the feedback for the at least one downlink transmission and the acknowledgment feedback for the at least one PSSCH transmission in the third slot; and

transmitting the at least one codebook entry to the network entity via at least one physical uplink control channel (PUCCH) transmission in the third slot.