Configuring transmission configuration indication states on an initial control resource set
Methods, systems, and devices for wireless communication are described. Generally, the described techniques provide for efficiently identifying spatial parameters for receiving control information in an initial coreset. In one example, a user equipment (UE) may receive a TCI state indicating reference signals quasi co-located with a control information transmission in a coreset, and the UE may also identify a quasi co-location (QCL) assumption in a random-access procedure indicating that a synchronization signal block (SSB) is quasi co-located with the control information transmission in the coreset. In this example, the UE may identify spatial parameters for monitoring the coreset for the control information transmission in accordance with the TCI state or the QCL assumption based on the timing of the indicated TCI state and the QCL assumption.
1. A method for wireless communication by a user equipment (UE), comprising:
receiving signaling indicating a transmission configuration indication (TCI) state corresponding to an initial control resource set (coreset);
identifying a quasi co-location (QCL) assumption associated with a synchronization signal block (SSB) selected in a random-access procedure, wherein the SSB is selected through the random-access procedure not initiated by a physical downlink control channel (PDCCH) order that triggers a non-contention based random-access procedure;
determining spatial parameters for monitoring the initial coreset for control information using the indicated TCI state or the identified QCL assumption based at least in part on whether the indicated TCI state is more recent than the identified QCL assumption; and
monitoring the initial coreset based at least in part on the determined spatial parameters.
2. The method of claim 1 , wherein the TCI state indicates a configuration of first and second reference signals that have a QCL relationship and a QCL type associated with the SSB.
3. The method of claim 1 , wherein receiving the signaling further comprises:
identifying that an SSB index of the SSB corresponds to a first control channel monitoring occasion of a plurality of control channel monitoring occasions; and
monitoring a common search space of the first control channel monitoring occasion for the control information.
4. The method of claim 1 , wherein the SSB has a QCL relationship with a reference signal of the indicated TCI state.
5. The method of claim 1 , further comprising:
transmitting a capability indicator that indicates a defined number of active TCI states; and
receiving configuration signaling indicating a defined number of QCL assumptions for at least one physical downlink shared channel (PDSCH) and at least one coreset for a bandwidth part based at least in part on transmitting the capability indicator.
6. The method of claim 5 , wherein the defined number of QCL assumptions active for the UE is less than or equal to the defined number of active TCI states.
7. The method of claim 1 , wherein determining the spatial parameters further comprises:
determining that the identified QCL assumption is ready to be applied a defined number of transmission time intervals after receiving a response from a base station in the random-access procedure.
8. The method of claim 1 , wherein the TCI state corresponding to the initial coreset is one of a set of TCI states configured in a physical downlink shared channel (PDSCH) configuration information element.
9. A method for wireless communication by a base station, comprising:
transmitting signaling indicating a transmission configuration indication (TCI) state corresponding to an initial control resource set (coreset);
identifying a quasi co-location (QCL) assumption associated with a synchronization signal block (SSB) selected in a random-access procedure, wherein the SSB is selected through the random-access procedure not initiated by a physical downlink control channel (PDCCH) order that triggers a non-contention based random-access procedure;
determining spatial parameters for the initial coreset for control information using the indicated TCI state or the identified QCL assumption based at least in part on whether the indicated TCI state is more recent than the identified QCL assumption; and
transmitting the control information via the initial coreset based at least in part on the determined spatial parameters.
10. The method of claim 9 , wherein the TCI state indicates a configuration of first and second reference signals that have a QCL relationship and a QCL type associated with the SSB.
11. The method of claim 9 , wherein transmitting the control information comprises:
transmitting the control information in a first control channel monitoring occasion of a plurality of control channel monitoring occasions, wherein a location of the first control channel monitoring occasion within a common search space of a control channel corresponding to the initial coreset is based at least in part on an SSB index of the SSB.
12. The method of claim 9 , wherein the SSB has a QCL relationship with a reference signal of the indicated TCI state.
13. The method of claim 9 , further comprising:
receiving a capability indicator that indicates a defined number of active TCI states; and
transmitting configuration signaling indicating a defined number of QCL assumptions for at least one physical downlink shared channel and at least one coreset for a bandwidth part based at least in part on receiving the capability indicator.
14. The method of claim 13 , wherein the defined number of QCL assumptions active for a user equipment (UE) is less than or equal to the defined number of active TCI states.
15. The method of claim 9 , wherein the TCI state corresponding to the initial coreset is one of a set of TCI states configured in a physical downlink shared channel (PDSCH) configuration information element.
16. An apparatus for wireless communication by a user equipment (UE), comprising: a processor, memory in electronic communication with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to:
receive signaling indicating a transmission configuration indication (TCI) state corresponding to an initial control resource set (coreset);
identify a quasi co-location (QCL) assumption associated with a synchronization signal block (SSB) selected in a random-access procedure, wherein the SSB is selected through the random-access procedure not initiated by a physical downlink control channel (PDCCH) order that triggers a non-contention based random-access procedure;
determine spatial parameters for monitoring the initial coreset for control information using the indicated TCI state or the identified QCL assumption based at least in part on whether the indicated TCI state is more recent than the identified QCL assumption; and
monitor the initial coreset based at least in part on the determined spatial parameters.
17. The apparatus of claim 16 , wherein the TCI state indicates a configuration of first and second reference signals that have a QCL relationship and a QCL type associated with the SSB.
18. The apparatus of claim 16 , wherein the instructions to receive the signaling further are executable by the processor to cause the apparatus to:
identify that an SSB index of the SSB corresponds to a first control channel monitoring occasion of a plurality of control channel monitoring occasions; and
monitor a common search space of the first control channel monitoring occasion for the control information.
19. The apparatus of claim 16 , wherein the SSB has a QCL relationship with a reference signal of the indicated TCI state.
20. The apparatus of claim 16 , wherein the instructions are further executable by the processor to cause the apparatus to:
transmit a capability indicator that indicates a defined number of active TCI states; and
receive configuration signaling indicating a defined number of QCL assumptions for at least one physical downlink shared channel (PDSCH) and at least one coreset for a bandwidth part based at least in part on transmitting the capability indicator.
21. The apparatus of claim 20 , wherein the defined number of QCL assumptions active for the UE is less than or equal to the defined number of active TCI states.
22. The apparatus of claim 16 , wherein the instructions to determine the spatial parameters further are executable by the processor to cause the apparatus to:
determine that the identified QCL assumption is ready to be applied a defined number of transmission time intervals after receiving a response from a base station in the random-access procedure.
23. The apparatus of claim 16 , wherein the TCI state corresponding to the initial coreset is one of a set of TCI states configured in a physical downlink shared channel (PDSCH) configuration information element.
24. An apparatus for wireless communication by a base station, comprising: a processor, memory in electronic communication with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to:
transmit signaling indicating a transmission configuration indication (TCI) state corresponding to an initial control resource set (coreset);
identify a quasi co-location (QCL) assumption associated with a synchronization signal block (SSB) selected in a random-access procedure, wherein the SSB is selected through the random-access procedure not initiated by a physical downlink control channel (PDCCH) order that triggers a non-contention based random-access procedure;
determine spatial parameters for the initial coreset for control information using the indicated TCI state or the identified QCL assumption based at least in part on whether the indicated TCI state is to be applied is more recent than a second time at which the identified QCL assumption; and
transmit the control information via the initial coreset based at least in part on the determined spatial parameters.
25. The apparatus of claim 24 , wherein the TCI state indicates a configuration of first and second reference signals that have a QCL relationship and a QCL type associated with the SSB.
26. The apparatus of claim 24 , wherein the instructions to transmit the control information further are executable by the processor to cause the apparatus to:
transmit the control information in a first control channel monitoring occasion of a plurality of control channel monitoring occasions, wherein a location of the first control channel monitoring occasion within a common search space of a control channel corresponding to the initial coreset is based at least in part on an SSB index of the SSB.
27. The apparatus of claim 24 , wherein the SSB has a QCL relationship with a reference signal of the indicated TCI state.
28. The apparatus of claim 24 , wherein the instructions are further executable by the processor to cause the apparatus to:
receive a capability indicator that indicates a defined number of active TCI states; and
transmit configuration signaling indicating a defined number of QCL assumptions for at least one physical downlink shared channel (PDSCH) and at least one coreset for a bandwidth part based at least in part on receiving the capability indicator.