UE triggered one-shot HARQ-ACK feedback

1. An apparatus for wireless communication at a user equipment (UE), comprising:

a memory; and

at least one processor coupled to the memory, the memory and the at least one processor configured to:

drop transmission of hybrid automatic repeat request-acknowledgment (HARQ-ACK) feedback for one or more downlink HARQ processes up to a threshold amount of the HARQ-ACK feedback, the threshold amount of the HARQ-ACK feedback being based on at least one of a type of overlapping transmission, a priority level of dropped bits, or a content of the HARQ-ACK feedback; and

transmit, to a base station, a combined HARQ-ACK feedback triggered by the UE dropping the threshold amount of the HARQ-ACK feedback, the combined HARQ-ACK feedback including the dropped HARQ-ACK feedback for the one or more downlink HARQ processes.

2. The apparatus of claim 1 , wherein the combined HARQ-ACK feedback comprises Type 3 HARQ-ACK feedback.

3. The apparatus of claim 1 , wherein the threshold amount of the HARQ-ACK feedback comprises a threshold number of dropped HARQ-ACK bits.

4. The apparatus of claim 1 , wherein the memory and the at least one processor are further configured to:

receive, from the base station, a configuration of the threshold amount of the HARQ-ACK feedback.

5. The apparatus of claim 1 , wherein the threshold amount of HARQ-ACK feedback that triggers the combined HARQ-ACK feedback is based on the type of the overlapping transmission, and the memory and the at least one processor are further configured to:

receive, from the base station, a configuration for a first threshold for the HARQ-ACK feedback that is dropped based on overlapping with an uplink transmission and a second threshold for the HARQ-ACK feedback that is dropped based on overlapping with downlink reception.

6. The apparatus of claim 1 , wherein the threshold amount of HARQ-ACK feedback that triggers the combined HARQ-ACK feedback is based on the priority level of the dropped bits, the memory and the at least one processor are further configured to:

receive, from the base station, a configuration for a first threshold number of dropped bits for the HARQ-ACK feedback of a first priority level and a second threshold number of dropped bits for the HARQ-ACK feedback of a second priority level.

7. The apparatus of claim 1 , wherein the threshold amount of the HARQ-ACK feedback that triggers the combined HARQ-ACK feedback is based on the content of the HARQ-ACK feedback, wherein the memory and the at least one processor are further configured to:

receive, from the base station, a configuration for at least one of a first threshold number of dropped acknowledgements (ACKs) and a second threshold number of dropped negative acknowledgments (NACKs).

8. The apparatus of claim 1 , wherein the memory and the at least one processor are further configured to:

receive an allocation of periodic uplink resources to transmit the combined HARQ-ACK feedback and to transmit the combined HARQ-ACK feedback in an instance of the periodic uplink resources.

9. The apparatus of claim 1 , wherein the memory and the at least one processor are further configured to:

compare the dropped HARQ-ACK feedback to the threshold amount of the HARQ-ACK feedback, the dropped HARQ-ACK feedback corresponding to a physical downlink shared channel (PDSCH) that ends a threshold amount of time before a beginning of an uplink resource for the combined HARQ-ACK feedback and to transmit the combined HARQ-ACK feedback based on the dropped HARQ-ACK feedback meeting or exceeding the threshold amount of the HARQ-ACK feedback.

10. The apparatus of claim 1 , wherein the combined HARQ-ACK feedback includes feedback for one or more physical downlink shared channel (PDSCH) transmissions that end a threshold amount of time before a beginning of an uplink resource for the combined HARQ-ACK feedback.

11. The apparatus of claim 1 , wherein the memory and the at least one processor are further configured to:

compare, to the threshold amount, dropped HARQ-ACK feedback scheduled for transmission in a first resource that starts no later than a starting time of an uplink resource for the combined HARQ-ACK feedback and to transmit the combined HARQ-ACK feedback based on the dropped HARQ-ACK feedback meeting or exceeding the threshold amount, or

compare, to the threshold amount, dropped HARQ-ACK feedback scheduled for transmission in a second resource that ends no later than the starting time of the uplink resource for the combined HARQ-ACK feedback and to transmit the combined HARQ-ACK feedback based on the dropped HARQ-ACK feedback meeting or exceeding the threshold amount.

12. The apparatus of claim 1 , wherein the combined HARQ-ACK feedback includes the HARQ-ACK feedback that is dropped from each of one or more resources that start no later than a starting time of an uplink resource for the combined HARQ-ACK feedback.

13. The apparatus of claim 1 , wherein the combined HARQ-ACK feedback includes the dropped HARQ-ACK feedback scheduled for transmission in a resource that ends no later than a starting time of an uplink resource for the combined HARQ-ACK feedback.

14. A method of wireless communication at a user equipment (UE), comprising:

dropping transmission of hybrid automatic repeat request-acknowledgment (HARQ-ACK) feedback for one or more downlink HARQ processes up to a threshold amount of the HARQ-ACK feedback, the threshold amount of the HARQ-ACK feedback being based on at least one of a type of overlapping transmission, a priority level of dropped bits, or a content of the HARQ-ACK feedback; and

transmitting, to a base station, a combined HARQ-ACK feedback triggered by the UE dropping the threshold amount of the HARQ-ACK feedback, the combined HARQ-ACK feedback including the dropped HARQ-ACK feedback for the one or more downlink HARQ processes.

15. The method of claim 14 , wherein the combined HARQ-ACK feedback comprises Type 3 HARQ-ACK feedback.

16. The method of claim 14 , wherein the threshold amount of the HARQ-ACK feedback comprises a threshold number of dropped HARQ-ACK bits.

17. The method of claim 14 , further comprising:

receiving, from the base station, a configuration of the threshold amount of the HARQ-ACK feedback.

18. The method of claim 14 , wherein the threshold amount of HARQ-ACK feedback that triggers the combined HARQ-ACK feedback is based on the type of the overlapping transmission, the method further comprising:

receiving, from the base station, a configuration for a first threshold for the HARQ-ACK feedback that is dropped based on overlapping with an uplink transmission and a second threshold for the HARQ-ACK feedback that is dropped based on overlapping with downlink reception.

19. The method of claim 14 , wherein the threshold amount of HARQ-ACK feedback that triggers the combined HARQ-ACK feedback is based on the priority level of the dropped bits, the method further comprising:

receiving, from the base station, a configuration for a first threshold number of dropped bits for the HARQ-ACK feedback of a first priority level and a second threshold number of dropped bits for the HARQ-ACK feedback of a second priority level.

20. The method of claim 14 , wherein the threshold amount of the HARQ-ACK feedback that triggers the combined HARQ-ACK feedback is based on the content of the HARQ-ACK feedback, the method further comprising:

receiving, from the base station, a configuration for at least one of a first threshold number of dropped acknowledgements (ACKs) and a second threshold number of dropped negative acknowledgments (NACKs).

21. The method of claim 14 , further comprising:

receiving an allocation of periodic uplink resources to transmit the combined HARQ-ACK feedback, wherein the UE transmits the combined HARQ-ACK feedback in an instance of the periodic uplink resources.

22. The method of claim 14 , further comprising:

comparing dropped HARQ-ACK feedback to the threshold amount of the HARQ-ACK feedback, the dropped HARQ-ACK feedback corresponding to a physical downlink shared channel (PDSCH) that ends a threshold amount of time before a beginning of an uplink resource for the combined HARQ-ACK feedback, wherein the UE transmits the combined HARQ-ACK feedback based on the dropped HARQ-ACK feedback meeting or exceeding the threshold amount of the HARQ-ACK feedback.

23. The method of claim 14 , wherein the combined HARQ-ACK feedback includes feedback for one or more physical downlink shared channel (PDSCH) transmissions that end a threshold amount of time before a beginning of an uplink resource for the combined HARQ-ACK feedback.

24. The method of claim 14 , further comprising:

comparing, to the threshold amount, dropped HARQ-ACK feedback scheduled for transmission in a first resource that starts no later than a starting time of an uplink resource for the combined HARQ-ACK feedback, wherein the UE transmits the combined HARQ-ACK feedback based on the dropped HARQ-ACK feedback meeting or exceeding the threshold amount, or

comparing, to the threshold amount, dropped HARQ-ACK feedback scheduled for transmission in a second resource that ends no later than the starting time of the uplink resource for the combined HARQ-ACK feedback, wherein the UE transmits the combined HARQ-ACK feedback based on the dropped HARQ-ACK feedback meeting or exceeding the threshold amount.

25. The method of claim 14 , wherein the combined HARQ-ACK feedback includes the HARQ-ACK feedback that is dropped from each of one or more resources that start no later than a starting time of an uplink resource for the combined HARQ-ACK feedback.

26. The method of claim 14 , wherein the combined HARQ-ACK feedback includes the dropped HARQ-ACK feedback scheduled for transmission in a resource that ends no later than a starting time of an uplink resource for the combined HARQ-ACK feedback.

27. An apparatus for wireless communication at a base station, comprising:

a memory; and

at least one processor coupled to the memory, the memory and the at least one processor configured to:

configure a user equipment (UE) for a threshold amount of hybrid automatic repeat request acknowledgement (HARQ-ACK) feedback, the threshold amount of the HARQ-ACK feedback being based on at least one of a type of overlapping transmission, a priority level of dropped bits, or a content of the HARQ-ACK feedback;

transmit physical downlink shared channel (PDSCH) transmissions for one or more HARQ processes; and

receive a combined HARQ ACK feedback triggered at the UE based on the threshold amount of dropped HARQ-ACK feedback, the combined HARQ-ACK feedback including the dropped HARQ-ACK feedback for one or more downlink HARQ processes.

28. The apparatus of claim 27 , wherein the memory and the at least one processor are further configured to:

allocate periodic uplink resources to the UE for transmission of the combined HARQ-ACK feedback.

29. A method of wireless communication at a base station, comprising:

configuring a user equipment (UE) for a threshold amount of hybrid automatic repeat request acknowledgement (HARQ-ACK) feedback, the threshold amount of the HARQ-ACK feedback being based on at least one of a type of overlapping transmission, a priority level of dropped bits, or a content of the HARQ-ACK feedback;

transmitting physical downlink shared channel (PDSCH) transmissions for one or more HARQ processes; and

receiving a combined HARQ-ACK feedback triggered at the UE based on the threshold amount of dropped HARQ-ACK feedback, the combined HARQ-ACK feedback including the dropped HARQ-ACK feedback for one or more downlink HARQ processes.

30. The method of claim 29 , further comprising:

allocating periodic uplink resources to the UE for transmission of the combined HARQ-ACK feedback, wherein the base station receives the combined HARQ-ACK feedback in an instance of the periodic uplink resources.