Resolving time-domain resource allocation ambiguity
Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may determining that a first physical downlink control channel (PDCCH) candidate and a second PDCCH candidate in a control resource set (CORESET) are aligned with each other, wherein the first PDCCH candidate is a common search space (CSS) candidate and the second PDCCH candidate is a UE-specific search space (UESS) candidate; and decode downlink control information in accordance with a selected candidate, of the CSS candidate or the UESS candidate, based at least in part on a rule indicating whether the time-domain resource allocation is to be determined in accordance with the CSS candidate or the UESS candidate. Numerous other aspects are provided.
1. A method of wireless communication performed by a user equipment (UE), comprising:
determining that a first physical downlink control channel (PDCCH) candidate and a second PDCCH candidate in a control resource set (CORESET) are aligned with each other, wherein the first PDCCH candidate is a common search space (CSS) candidate and the second PDCCH candidate is a UE-specific search space (UESS) candidate; and
decoding downlink control information in accordance with a rule indicating whether the downlink control information is to be decoded in accordance with the CSS candidate or the UESS candidate,
wherein the rule indicates that the downlink control information is to be decoded in accordance with the CSS candidate when the downlink control information, when decoded, is not distinguishable as associated with the CSS candidate or the UESS candidate.
2. The method of claim 1 , wherein the CORESET is a CORESET #0.
3. The method of claim 1 , wherein the CSS candidate and the UESS candidate are associated with a same set of control channel elements.
4. The method of claim 3 , wherein a CSS of the CSS candidate and a UESS of the UESS candidate are configured in the CORESET #0.
5. The method of claim 1 , wherein the CSS candidate and the UESS candidate are associated with a same scrambling identifier.
6. The method of claim 1 , wherein the CSS candidate and the UESS candidate have a same downlink control information size and a same downlink control information format.
7. The method of claim 6 , wherein the same downlink control information format is a fallback downlink control information format.
8. The method of claim 1 , wherein the CSS candidate and the UESS candidate are associated with a same radio network temporary identifier (RNTI) type.
9. The method of claim 8 , wherein the RNTI type is associated with at least one of a cell RNTI, a configured scheduling RNTI, or a modulation and coding scheme cell RNTI.
10. The method of claim 1 , wherein the rule indicates that if there is at least one candidate in a first search space, of a CSS and a UESS, that is not distinguishable from a candidate in a second search space, of the CSS and the UESS, then the downlink control information is to be decoded in accordance with the selected candidate, wherein the selected candidate is associated with the first search space.
11. The method of claim 1 , wherein decoding the downlink control information in accordance with the selected candidate further comprises:
dropping a candidate, of the UESS candidate and the CSS candidate, other than the selected candidate.
12. The method of claim 11 , wherein dropping the candidate further comprises:
decoding the downlink control information of the selected candidate and not the candidate other than the selected candidate.
13. The method of claim 1 , wherein the selected candidate is the CSS candidate.
14. The method of claim 1 , wherein the downlink control information includes information indicating a time-domain resource allocation.
15. The method of claim 14 , wherein decoding the downlink control information further comprises identifying the time-domain resource allocation in accordance with the selected candidate; and
wherein the method further comprises:
receiving or transmitting information based at least in part on the time-domain resource allocation.
16. A user equipment (UE) for wireless communication, comprising:
a memory; and
one or more processors coupled to the memory, the memory and the one or more processors configured to:
determine that downlink control information is associated with a control resource set (CORESET) that includes a common search space (CSS) candidate and a UE-specific search space (UESS) candidate that are aligned with each other; and
decode downlink control information at least in part in accordance with a rule indicating whether the downlink control information is to be decoded in accordance with the CSS candidate or the UESS candidate,
wherein the rule indicates that the downlink control information is to be decoded in accordance with the CSS candidate when the downlink control information, when decoded, is not distinguishable as associated with the CSS candidate or the UESS candidate.
17. The UE of claim 16 , wherein a CSS of the CSS candidate and a UESS of the UESS are configured in the CORESET #0.
18. The UE of claim 17 , wherein the CORESET is a CORESET #0.
19. The UE of claim 17 , wherein the CSS candidate and the UESS candidate are associated with a same set of control channel elements.
20. The UE of claim 17 , wherein the CSS candidate and the UESS candidate are associated with a same scrambling identifier.
21. The UE of claim 17 , wherein the CSS candidate and the UESS candidate are associated with a same radio network temporary identifier (RNTI) type.
22. The UE of claim 21 , wherein the RNTI type is associated with at least one of a cell RNTI, a configured scheduling RNTI, or a modulation and coding scheme cell RNTI.
23. The UE of claim 16 , wherein the CSS candidate and the UESS candidate have a same downlink control information size and a same downlink control information format.
24. The UE of claim 23 , wherein the same downlink control information format is a fallback downlink control information format.
25. An apparatus for wireless communication, comprising:
means for determining that a first physical downlink control channel (PDCCH) candidate and a second PDCCH candidate in a control resource set (CORESET) are aligned with each other, wherein the first PDCCH candidate is a common search space (CSS) candidate and the second PDCCH candidate is a UE-specific search space (UESS) candidate; and
means for decoding downlink control information at least in part in accordance with a rule indicating whether the downlink control information is to be decoded in accordance with the CSS candidate or the UESS candidate,
wherein the rule indicates that the downlink control information is to be decoded in accordance with the CSS candidate when the downlink control information, when decoded, is not distinguishable as associated with the CSS candidate or the UESS candidate.
26. The apparatus of claim 25 , wherein the CORESET is a CORESET #0.
27. The apparatus of claim 26 , wherein a CSS of the CSS candidate and a UESS of the UESS candidate are configured in the CORESET #0.
28. A non-transitory computer-readable medium storing one or more instructions for wireless communication, the one or more instructions comprising:
one or more instructions that, when executed by one or more processors of a user equipment (UE), cause the one or more processors to:
determine that a first physical downlink control channel (PDCCH) candidate and a second PDCCH candidate in a control resource set (CORESET) are aligned with each other, wherein the first PDCCH candidate is a common search space (CSS) candidate and the second PDCCH candidate is a UE-specific search space (UESS) candidate; and
decode downlink control information at least in part in accordance with a rule indicating whether the downlink control information is to be decoded in accordance with the CSS candidate or the UESS candidate,
wherein the rule indicates that the downlink control information is to be decoded in accordance with the CSS selected candidate when the downlink control information, when decoded, is not distinguishable as associated with the CSS candidate or the UESS candidate.