Pruning rules for DCI repetition
Certain aspects of the present disclosure provide techniques for utilizing and processing repeated DCI transmissions that schedule common uplink or downlink transmissions. The techniques allow a UE to decide which repeated DCI to use for determining resources for the uplink or downlink transmissions.
1. A method for wireless communications by a user equipment (UE), comprising:
detecting at least first downlink control information (DCI) and second DCI, wherein:
the second DCI is a repetition of the first DCI, and
the first and second DCI both indicate same scheduling information for a common uplink data transmission or a downlink data transmission;
selecting at least one of the first or second DCI to use for determining parameters to use for the uplink data transmission, or for reception of the downlink data transmission; and
processing the DL data transmission or sending the uplink data transmission based on the determined parameters.
2. The method of claim 1 , wherein the first and second DCIs span at least one of different time slots or symbols.
3. The method of claim 1 , wherein:
the first DCI and the second DCI occur in a same physical downlink control channel (PDCCH) monitoring occasion; and
the selecting is based on an index of a first CCE of each DCI.
4. The method of claim 1 , wherein the DCIs are detected in different transmission time intervals (TTIs).
5. The method of claim 1 , wherein the selecting comprises selecting the first or second DCI that occurs in a later occurring physical downlink control channel (PDCCH) monitoring occasion.
6. The method of claim 1 , wherein the UE:
calculates a first index that points to resources for the uplink control transmission based on parameters of the first DCI;
calculates a second index that points to resources for the uplink control transmission based on parameters of the second DCI; and
choosing an index to use for determining resources to use for the uplink control transmission based on a function of the first index and the second index.
7. The method of claim 1 , wherein:
the first and second DCI are detected in different CORESETs, each CORESET in a different CORESET group; and
the first or second DCI is selected based on the CORESET group of its corresponding CORESET.
8. The method of claim 1 , wherein:
the first or second DCI is selected based on a corresponding detection confidence level.
9. The method of claim 8 , wherein the detection confidence level of each DCI is determined based on at least one of: channel quality of demodulation reference signals (DMRS), aggregation level (AL), or log likelihood ratio (LLR) values.
10. The method of claim 1 , wherein:
the UE determines different resources to use for the uplink transmission based on both the first and second DCI; and
the UE sends the uplink transmission using the different resources.
11. The method of claim 1 , wherein:
values of at least one field of the first and second DCIs are different; and
the UE is configured to determine the second DCI is a repetition of the first DCI based on one or more conditions.
12. The method of claim 11 , wherein the conditions comprise at least one of:
scheduling information for the first and second DCI both point to same time and frequency domain resources;
the first and second DCI indicate at least one of a same hybrid automatic repeat request (HARQ) process ID, same NDI value, or same DCI identifier; or
the first and second DCI have a same redundancy version (RV), modulation coding scheme (MCS), or antenna port.
13. The method of claim 11 , further comprising ignoring both DCI if:
scheduling information for the first and second DCI both point to same time and frequency domain resources; and
the first and second DCI indicate different hybrid automatic repeat request (HARQ) process IDs or NDI values.
14. The method of claim 11 , wherein the UE uses information from both DCIs only when the information is not conflicting.
15. The method of claim 11 , wherein the UE is configured to select a DCI based on a value of a PDSCH-to-HARQ-timing indicator field.
16. The method of claim 11 , wherein the one or more conditions comprise at least one of:
determining the first and second DCIs are transmitted with different beams, transmission configuration indicator (TCI) states, transmission reception points (TRPs), or panels; or
determining the DCIs are received on different UE panels or received on different CORESETs from different CORESET groups with different TCI states.
17. The method of claim 1 , wherein the same scheduling information comprises similar scheduling information.
18. An apparatus for wireless communications by a user equipment (UE), comprising:
at least one memory having executable instructions stored thereon; and
one or more processors configured, individually or in any combination, to execute the executable instructions to cause the apparatus to:
detect at least first downlink control information (DCI) and second DCI, wherein:
the second DCI is a repetition of the first DCI, and
the first and second DCI both indicate same scheduling information for a common uplink data transmission or a downlink data transmission;
select at least one of the first or second DCI to use for determining parameters to use for the uplink data transmission, or for reception of the downlink data transmission; and
process the DL data transmission or sending the uplink data transmission based on the determined parameters.
19. The apparatus of claim 18 , wherein the first and second DCIs span at least one of different time slots or symbols.
20. The apparatus of claim 18 , wherein:
the first DCI and the second DCI occur in a same physical downlink control channel (PDCCH) monitoring occasion; and
the selecting is based on an index of a first CCE of each DCI.
21. The apparatus of claim 18 , wherein the DCIs are detected in different transmission time intervals (TTIs).
22. The apparatus of claim 18 , wherein to select at least one of the first or second DCI, the one or more processors, individually or in any combination, are configured to cause the apparatus to select the first or second DCI that occurs in a later occurring physical downlink control channel (PDCCH) monitoring occasion.
23. The apparatus of claim 18 , wherein the one or more processors, individually or in any combination, are configured to cause the apparatus to:
calculate a first index that points to resources for the uplink control transmission based on parameters of the first DCI;
calculate a second index that points to resources for the uplink control transmission based on parameters of the second DCI; and
choose an index to use for determining resources to use for the uplink control transmission based on a function of the first index and the second index.
24. The apparatus of claim 18 , wherein:
the first and second DCI are detected in different CORESETs, each CORESET in a different CORESET group; and
the first or second DCI is selected based on the CORESET group of its corresponding CORESET.
25. The apparatus of claim 18 , wherein:
values of at least one field of the first and second DCIs are different; and
the apparatus is configured to determine the second DCI is a repetition of the first DCI based on one or more conditions.
26. The apparatus of claim 25 , wherein the conditions comprise at least one of:
scheduling information for the first and second DCI both point to same time and frequency domain resources;
the first and second DCI indicate at least one of a same hybrid automatic repeat request (HARQ) process ID, same NDI value, or same DCI identifier; or
the first and second DCI have a same redundancy version (RV), modulation coding scheme (MCS), or antenna port.
27. The apparatus of claim 25 , further comprising ignoring both DCI if:
scheduling information for the first and second DCI both point to same time and frequency domain resources; and
the first and second DCI indicate different hybrid automatic repeat request (HARQ) process IDs or NDI values.
28. The apparatus of claim 25 , wherein the apparatus is configured to select a DCI based on a value of a PDSCH-to-HARQ-timing indicator field.
29. The apparatus of claim 25 , wherein the one or more conditions comprise at least one of:
determining the first and second DCIs are transmitted with different beams, transmission configuration indicator (TCI) states, transmission reception points (TRPs), or panels; or
determining the DCIs are received on different UE panels or received on different CORESETs from different CORESET groups with different TCI states.