Conditions to delay HARQ-ACK for SPS PDSCH
Aspects of the present disclosure relate to wireless communications, and more particularly, to mechanisms for using block acknowledgments to acknowledge semi-persistently scheduled (SPS) occasions from multiple SPS configurations. An example method generally includes determining that a slot scheduled for reporting acknowledgment feedback for an SPS physical downlink shared channel (PDSCH) potentially overlaps with at least one downlink or flexible symbol, deciding whether to cancel or to delay reporting the acknowledgment feedback to a network entity based on one or more conditions, and canceling or delaying reporting the acknowledgment feedback to the network entity, in accordance with the decision.
1. A method for wireless communications by a user equipment (UE), comprising:
determining that a slot scheduled for reporting acknowledgment feedback for a semi-persistently scheduled (SPS) physical downlink shared channel (PDSCH) overlaps with at least one downlink or flexible symbol;
deciding to delay reporting the acknowledgment feedback to a network entity if a first condition related to a cause of the overlap is met or to cancel reporting the acknowledgment feedback to the network entity if a second condition related to a cause of the overlap is met; and
canceling or delaying reporting the acknowledgment feedback to the network entity, in accordance with the decision.
2. The method of claim 1 , wherein
the first condition is considered met if at least one of:
the overlap is due to signaling indicating semi-static downlink symbols via time division duplexing (TDD) configuration, synchronization signal block (SSB) configuration, or control resource set (CORESET) configuration signaling; or
the overlap is due to a downlink control information (DCI) switching one or more semi-static flexible symbols to downlink symbols.
3. The method of claim 2 , wherein the decision is to delay reporting the acknowledgment feedback to a next available slot or subslot if the first condition is met.
4. The method of claim 1 , wherein the second condition is considered met if at least one of:
the overlap is due to a downlink control information (DCI) switching one or more semi-static flexible symbols to downlink symbols;
the overlap is due to a slot format indicator (SFI) indicating the one or more semi-static flexible symbols as downlink or flexible symbols; or
the UE fails to receive the SFI.
5. The method of claim 1 , wherein the decision is based on a configuration signaled to the UE.
6. The method of claim 5 , wherein the configuration configures the UE to delay reporting the acknowledgment feedback when the first condition is met.
7. The method of claim 5 , wherein the configuration configures the UE to cancel reporting the acknowledgment feedback when the second condition is met.
8. The method of claim 5 , wherein the configuration configures the UE to cancel or to delay reporting the acknowledgment feedback when the UE fails to receive the SFI.
9. The method of claim 5 , wherein the configuration configures the UE to cancel or to delay reporting the acknowledgment feedback when the overlap is due to a slot format indicator (SFI) indicating the one or more semi-static flexible symbols as downlink or flexible symbols.
10. The method of claim 5 , wherein the configuration configures the UE to:
delay reporting the acknowledgement feedback when the overlap is due to a downlink control information (DCI) switching one or more semi-static flexible symbols to downlink symbols; or
cancel reporting the acknowledgement feedback when the overlap is due to a slot format indicator (SFI) indicating the one or more semi-static flexible symbols as downlink or flexible symbols or the UE fails to receive the SFI.
11. The method of claim 5 , wherein the configuration configures the UE to:
cancel reporting the acknowledgement feedback if either the overlap is due to a slot format indicator (SFI) indicating the one or more semi-static flexible symbols as downlink or flexible symbols or the UE fails to receive the SFI.
12. A method for wireless communications by a network entity, comprising:
determining that a slot scheduled for a user equipment (UE) to report acknowledgment feedback for a semi-persistently scheduled (SPS) physical downlink shared channel (PDSCH) overlaps with at least one downlink or flexible symbol; and
deciding to monitor for the UE to delay reporting the acknowledgment feedback if a first condition related to a cause of the overlap is met or to refrain from monitoring for the acknowledgment feedback if a second condition related to a cause of the overlap is met.
13. The method of claim 12 , wherein
the first condition is considered met if at least one of:
the overlap is due to signaling indicating semi-static downlink symbols via time division duplexing (TDD) configuration, synchronization signal block (SSB) configuration, or control resource set (CORESET) configuration signaling; or
the overlap is due to a downlink control information (DCI) switching one or more semi-static flexible symbols to downlink symbols.
14. The method of claim 13 , wherein the decision is to monitor for the UE to delay reporting the acknowledgment feedback to a next available slot or subslot if the first condition is met.
15. The method of claim 14 , wherein the second condition is considered met if at least one of:
the overlap is due to a downlink control information (DCI) switching one or more semi-static flexible symbols to downlink symbols;
the overlap is due to a slot format indicator (SFI) indicating the one or more semi-static flexible symbols as downlink or flexible symbols; or
the UE fails to receive the SFI.
16. The method of claim 12 , further comprising signaling, to the UE, a configuration configuring the UE whether to delay or cancel reporting the acknowledgment feedback if the first condition or the second condition is met.
17. The method of claim 16 , wherein the configuration configures the UE to delay reporting the acknowledgment feedback when the first condition is met.
18. The method of claim 16 , wherein the configuration configures the UE to cancel reporting the acknowledgment feedback when the second condition is met.
19. The method of claim 16 , wherein the configuration configures the UE to cancel reporting the acknowledgment feedback when the UE fails to receive the SFI.
20. The method of claim 16 , wherein the configuration configures the UE to cancel or to delay reporting the acknowledgment feedback when the overlap is due to a slot format indicator (SFI) indicating the one or more semi-static flexible symbols as downlink or flexible symbols.
21. The method of claim 16 , wherein the configuration configures the UE to:
delay reporting the acknowledgement feedback when the overlap is due to a downlink control information (DCI) switching one or more semi-static flexible symbols to downlink symbols; or
cancel reporting the acknowledgement feedback when the overlap is due to a slot format indicator (SFI) indicating the one or more semi-static flexible symbols as downlink or flexible symbols or the UE fails to receive the SFI.
22. The method of claim 16 , wherein the configuration configures the UE to:
cancel reporting the acknowledgement feedback if either the overlap is due to a slot format indicator (SFI) indicating the one or more semi-static flexible symbols as downlink or flexible symbols or the UE fails to receive the SFI.
23. An apparatus for wireless communications by a user equipment (UE), comprising:
at least one processor and a memory configured to
determine that a slot scheduled for reporting acknowledgment feedback for a semi-persistently scheduled (SPS) physical downlink shared channel (PDSCH) overlaps with at least one downlink or flexible symbol;
decide to delay reporting the acknowledgment feedback to a network entity if a first condition related to a cause of the overlap is met or to cancel reporting the acknowledgment feedback to the network entity if a second condition related to a cause of the overlap is met; and
cancel or delay reporting the acknowledgment feedback to the network entity, in accordance with the decision.
24. An apparatus for wireless communications by a network entity, comprising:
at least one processor and a memory configured to
determine that a slot scheduled for a user equipment (UE) to report acknowledgment feedback for a semi-persistently scheduled (SPS) physical downlink shared channel (PDSCH) potentially overlaps with at least one downlink or flexible symbol; and
decide to monitor for the UE to delay reporting the acknowledgment feedback if a first condition related to a cause of the overlap is met or to refrain from monitoring for the acknowledgment feedback if a second condition related to a cause of the overlap is met.