Method and apparatus for managing multiple sets of transmission configuration indicator states
A method and apparatus are provided, in which an activation command is received ( 402 ), which indicates a first set of transmission configuration indicator (TCI) states to select between, which are to be used with transmissions scheduled using a first downlink control information (DCI) format. A number of states included in the first set corresponds to a selection field associated with the first DCI format having a first size. A second set of TCI states to select between, which are to be used with transmissions scheduled using a second DCI format is determined ( 404 ). A number of states included in the second set corresponds to a selection field associated with the second DCI format having a second size, where the second size is different than the first size. Transmissions scheduled using the second DCI format are received ( 406 ).
1 . A method performed by a user equipment (UE), the method comprising:
receiving an activation command indicating a first set of transmission configuration indicator (TCI) states to select between for use with transmissions scheduled using a first downlink control information (DCI) format, wherein a first number of TCI states included in the first set of TCI states corresponds to a first selection field associated with the first DCI format and having a first size, the first size corresponding to a first number of discrete entries of the first selection field;
determining a second set of TCI states to select between for use with transmissions scheduled using a second DCI format, wherein a second number of TCI states included in the second set of TCI states corresponds to a second selection field associated with the second DCI format and having a second size different than the first size, the second size corresponding to a second number of discrete entries of the second selection field; and
receiving transmissions scheduled using the second DCI format using a TCI state selected from the second set of TCI states,
wherein the second set of TCI states includes TCI states beginning with a first K number of TCI states from the first set of TCI states, wherein K is equal to the second number of TCI states that can be distinguished using the second selection field having the second size and associated with the second DCI format.
2 . The method of claim 1 , wherein the second size is smaller than the first size, the second number of TCI states is less than the first number of TCI states, and the second selection field is associated with fewer TCI states than the first selection field.
3 . The method of claim 1 , wherein each of the first number of discrete entries and the second number of discrete entries corresponds to a respective number of entries equal to two raised to a power W, where W is a number of bits in each of the first selection field and the second selection field.
4 . The method of claim 1 , wherein the second set of TCI states is a subset of the first set of TCI states.
5 . The method of claim 1 , wherein each TCI state in the first set of TCI states indicated in the activation command is respectively mapped to a corresponding position associated with a predefined ordered arrangement within the first set.
6 . The method of claim 5 , wherein the TCI states included in the second set of TCI states correspond to a predetermined subgrouping of TCI states from the first set of TCI states based upon the corresponding position within the first set.
7 . The method of claim 6 , wherein the predetermined subgrouping of TCI states from the first set of TCI states that are included in the second set of TCI states are identified in a predetermined bitmap.
8 . The method of claim 7 , further comprising receiving a medium access control-control element (MAC-CE) that includes an indication of the predetermined bitmap.
9 . The method of claim 1 , further comprising receiving the transmissions scheduled using the second DCI format via a physical downlink shared channel (PDSCH).
10 . The method of claim 1 , further comprising receiving a DCI having the second DCI format via a physical downlink control channel (PDCCH).
11 . The method of claim 1 , further comprising receiving the activation command as part of a medium access control-control element (MAC-CE).
12 . The method of claim 1 , wherein use of the second DCI format is associated with ultra reliable low latency communications.
13 . The method of claim 1 , wherein the determining comprises:
mapping the first set of TCI states to a first set of codepoints of the first selection field associated with the first DCI format; and
mapping the second set of TCI states to a second set of codepoints of the second selection field associated with the second DCI format.
14 . The method of claim 13 , further comprising:
receiving a first DCI message having the first DCI format, wherein the first DCI message schedules an eMBB PDSCH transmission, and wherein a value of the first selection field included in the first DCI message indicates a first TCI state from the first set of TCI states;
receiving the eMBB PDSCH transmission according to the first TCI state based at least in part on the mapping of the first set of TCI states to the first set of codepoints;
receiving a second DCI message having the second DCI format, wherein the second DCI message schedules a URLLC PDSCH transmission, and wherein a value of the second selection field included in the second DCI message indicates a second TCI state from the second set of TCI states; and
receiving the URLLC PDSCH transmission according to the second TCI state based at least in part on the mapping of the second set of TCI states to the second set of codepoints.
15 . The method of claim 1 , wherein the second set of TCI states comprises a subset of the first set of TCI states that starts from the beginning of the first set of TCI states.
16 . A user equipment (UE) for wireless communication, comprising:
at least one memory; and
at least one processor coupled with the at least one memory and configured to cause the UE to:
receive an activation command indicating a first set of transmission configuration indicator (TCI) states to select between for use with transmissions scheduled using a first downlink control information (DCI) format, wherein a first number of TCI states included in the first set of TCI states corresponds to a first selection field associated with the first DCI format and having a first size, the first size corresponding to a first number of discrete entries of the first selection field;
determine a second set of TCI states to select between for use with transmissions scheduled using a second DCI format, wherein a second number of TCI states included in the second set of TCI states corresponds to a second selection field associated with the second DCI format and having a second size different than the first size, the second size corresponding to a second number of discrete entries of the second selection field; and
receive transmissions scheduled using the second DCI format using a TCI state selected from the second set of TCI states,
wherein the second set of TCI states includes TCI states beginning with a first K number of TCI states from the first set of TCI states, wherein K is equal to the second number of TCI states that can be distinguished using the second selection field having the second size and associated with the second DCI format.
17 . The UE of claim 16 , wherein the second size is smaller than the first size, the second number of TCI states is less than the first number of TCI states, and the second selection field is associated with fewer TCI states than the first selection field.
18 . The UE of claim 16 , wherein each of the first number of discrete entries and the second number of discrete entries corresponds to a respective number of entries equal to two raised to a power W, where W is a number of bits in each of the first selection field and the second selection field.
19 . The UE of claim 16 , wherein the second set of TCI states is a subset of the first set of TCI states.
20 . The UE of claim 16 , wherein each TCI state in the first set of TCI states indicated in the activation command is respectively mapped to a corresponding position associated with a predefined ordered arrangement within the first set.
21 . A processor for wireless communication, comprising:
at least one controller coupled with at least one memory and configured to cause the processor to:
receive an activation command indicating a first set of transmission configuration indicator (TCI) states to select between for use with transmissions scheduled using a first downlink control information (DCI) format, wherein a first number of TCI states included in the first set of TCI states corresponds to a first selection field associated with the first DCI format and having a first size, the first size corresponding to a first number of discrete entries of the first selection field;
determine a second set of TCI states to select between for use with transmissions scheduled using a second DCI format, wherein a second number of TCI states included in the second set of TCI states corresponds to a second selection field associated with the second DCI format and having a second size different than the first size, the second size corresponding to a second number of discrete entries of the second selection field; and
receive transmissions scheduled using the second DCI format using a TCI state selected from the second set of TCI states,
wherein the second set of TCI states includes TCI states beginning with a first K number of TCI states from the first set of TCI states, wherein K is equal to the second number of TCI states that can be distinguished using the second selection field having the second size and associated with the second DCI format.
22 . The processor of claim 21 , wherein the second size is smaller than the first size, the second number of TCI states is less than the first number of TCI states, and the second selection field is associated with fewer TCI states than the first selection field.