Acknowledgement signaling for multi-PUSCH and multi-PDSCH scheduling
Systems and methods disclosed herein relate to acknowledgement signaling sent by a user equipment (UE) in response to downlink control information (DCI) received from a base station that schedules the use of multiple physical uplink control channels (multi-PUSCH) or multiple physical downlink control channels (multi-PDSCH). Acknowledgement signaling may inform the base station that DCI scheduling the multi-PUSCH/multi-PDSCH was received (or not), so that the base station may reclaim those scheduled resources in the case that the UE remains unaware of them. Methods for performing this signaling include, e.g., the use of HARQ-ACK codebooks (whether in a semi-static or dynamic manner), and aperiodic sounding reference signals (A-SRS). Embodiments involving such DCI received across multiple component carriers of different serving cells of the UE are contemplated. Acknowledgment signaling according to multi-PUSCH/multi-PDSCH subgroups, monitoring windows, acknowledgment signaling enablement/disablement, and the use of DCI to trigger acknowledgment signaling are also discussed.
1. A method of a user equipment (UE), comprising:
receiving, from a base station, downlink control information (DCI) configured to schedule multiple shared channels;
sending, to the base station, acknowledgement signaling that indicates that the UE received the DCI, wherein the acknowledgement signaling is sent using a hybrid automatic repeat request (HARQ) acknowledgement (HARQ-ACK) bit at least a pre-determined number of symbols after a last symbol of a physical downlink control channel (PDCCH) comprising the DCI; and
performing, with the base station, one or more communications using the multiple shared channels scheduled by the DCI.
2. The method of claim 1 , wherein the multiple shared channels comprise one of multiple physical uplink shared channels (multi-PUSCH) and multiple physical downlink shared channels (multi-PDSCH).
3. The method of claim 1 , wherein the pre-determined number of symbols is determined based on a subcarrier spacing (SCS) of the PDCCH.
4. The method of claim 1 , wherein:
the HARQ-ACK bit is sent in a first slot that occurs a number of slots after a slot of the PDCCH; and
the first slot occurs after the pre-determined number of symbols.
5. The method of claim 4 , wherein:
the number of slots is one of a set of values configured by radio resource control (RRC) signaling; and
the DCI indicates the one of the set of values.
6. The method of claim 4 , wherein the number of slots is pre-configured at the UE.
7. The method of claim 1 , wherein the acknowledgement signaling is sent in a hybrid automatic repeat request (HARQ) acknowledgement (HARQ-ACK) codebook.
8. The method of claim 7 , wherein:
the DCI comprises a first DCI received at the UE during a first monitoring occasion (MO) and a second DCI received at the UE during a second MO; and
the acknowledgement signaling comprises a first bit representing that the first DCI was received during the first MO and a second bit representing the second DCI was received during the second MO.
9. The method of claim 7 , wherein:
the DCI is received at the UE during a first monitoring occasion (MO);
the acknowledgement signaling comprises a first bit representing that the DCI was received during the first MO, and;
the acknowledgement signaling comprises a second bit representing that no DCI was received during a second MO.
10. The method of claim 7 , wherein:
the DCI comprises a first DCI received during a first MO on a first component carrier (CC) of a plurality of CC and a second DCI received during a second MO on a second CC of the plurality of CC; and
the acknowledgement signaling comprises a first bit indicating that the first DCI was received during the first MO and a second bit indicating that the second DCI was received during the second MO.
11. The method of claim 10 , wherein the acknowledgement signaling comprises a third bit indicating that no DCI was received during a third MO.
12. The method of claim 10 , wherein:
the first bit is ordered in the HARQ-ACK codebook according to an order of the first CC relative to the second CC; and
the second bit is ordered in the HARQ-ACK codebook according to an order of the second CC relative to the first CC.
13. The method of claim 10 , wherein:
the first MO occurs during a first slot and the second MO occurs during a second slot;
the first bit is ordered in the HARQ-ACK codebook according to a time of the first slot relative to the second slot; and
the second bit is ordered in the HARQ-ACK codebook according to a time of the second slot relative to the first slot.
14. The method of claim 10 , wherein the first DCI indicates an accumulative number of MO on which the DCI is sent by the base station on the plurality of CC prior to a time of a slot during which the first DCI is received and through the plurality of CC on the slot during which the first DCI is received until the first MO.
15. The method of claim 10 , wherein the first DCI indicates a total number of MO on which the DCI is sent by the base station on the plurality of CC by a time of a slot during which the first DCI is received.
16. The method of claim 7 , wherein the HARQ-ACK codebook is sent in response to a receipt from the base station of a triggering DCI that indicates that the acknowledgement signaling is to be sent by the UE.
17. The method of claim 16 , wherein the DCI is received during a monitoring window defined relative to a physical uplink control channel (PUCCH) triggered by the triggering DCI.
18. The method of claim 17 , wherein a size of the monitoring window is configured by radio resource control (RRC) signaling.
19. The method of claim 17 , wherein a size of the monitoring window is indicated by one of medium access control (MAC) control element (CE) (MAC-CE) signaling and the triggering DCI.