Transmission configuration indicator states in downlink control information format 1_2
Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, from a base station, downlink control information (DCI) in format 1_2 that includes an indicator with a first quantity of codepoints that is smaller than a second quantity of activated transmission configuration indicator (TCI) states. Accordingly, the UE may apply a TCI state, from the first quantity of activated TCI states out of the second quantity of activated TCI states, according to the indicator. Numerous other aspects are described.
1 . An apparatus for wireless communication at a user equipment (UE), comprising:
a memory; and
one or more processors, coupled to the memory, configured to:
receive, from a network entity, downlink control information (DCI) in format 1_2 that includes an indicator associated with a first quantity of codepoints that is smaller than a second quantity of activated transmission configuration indicator (TCI) states,
the DCI including a TCI field of m bits,
m being an integer,
the first quantity of the codepoints relating to a subset of the second quantity of the activated TCI states, and
the subset comprising a first 2 m TCI states of the second quantity of the activated TCI states; and
apply a TCI state, from the subset, according to the indicator.
2 . The apparatus of claim 1 , wherein a quantity of the first 2 m TCI states is a same quantity as the first quantity of the codepoints.
3 . The apparatus of claim 2 , wherein the codepoints are based on a control element that activated the activated TCI states.
4 . The apparatus of claim 2 , wherein the first 2 m TCI states are based on a sequential order of the corresponding codepoints.
5 . The apparatus of claim 1 , wherein the first 2 m TCI states are based on corresponding indices associated with the activated TCI states.
6 . The apparatus of claim 5 , wherein the corresponding indices are based on a radio resource control (RRC) message that indicated a set of TCI states that includes the activated TCI states.
7 . The apparatus of claim 5 , wherein the first 2 m TCI states are based on a sequential order of the corresponding indices.
8 . The apparatus of claim 1 , wherein the activated TCI states are activated by a control element associated with a single transmit-receive point (TRP) of the network entity.
9 . The apparatus of claim 1 , wherein the activated TCI states are activated by a control element associated with a control resource (CORESET) pool identifier for one of a plurality of transmit-receive points (TRPs) of the network entity.
10 . The apparatus of claim 1 , wherein the one or more processors are further configured to:
receive, from the network entity, an indication that the indicator will include one bit or two bits,
wherein the TCI state is selected from the first 2 m TCI states based on the indication.
11 . The apparatus of claim 10 , wherein the indication is included in a radio resource control (RRC) message.
12 . The apparatus of claim 1 , wherein the one or more processors are further configured to:
receive, from the network entity, data on a physical downlink shared channel (PDSCH) scheduled using the DCI,
wherein the data is received using the applied TCI state.
13 . An apparatus for wireless communication at a network entity, comprising:
a memory; and
one or more processors, coupled to the memory, configured to:
transmit downlink control information (DCI) in format 1_2 that includes an indicator associated with a first quantity of codepoints that is smaller than a second quantity of activated transmission configuration indicator (TCI) states,
the DCI including a TCI field of m bits,
m being an integer,
the first quantity of the codepoints relating to a subset of the second quantity of the activated TCI states, and
the subset comprising a first 2 m TCI states of the second quantity of the activated TCI states; and
apply a TCI state, from the subset, according to the indicator.
14 . The apparatus of claim 13 , wherein a quantity of the first 2 m TCI states is a same quantity as the first quantity of the codepoints.
15 . The apparatus of claim 14 , wherein the codepoints are based on a control element that activated the activated TCI states.
16 . The apparatus of claim 14 , wherein the first 2 m TCI states are based on a sequential order of the codepoints.
17 . The apparatus of claim 13 , wherein the one or more processors are further configured to:
transmit an indication that the indicator will include one bit or two bits,
wherein the TCI state is selected from the first 2 m TCI states based on the indication.
18 . The apparatus of claim 17 , wherein the indication is included in a radio resource control (RRC) message.
19 . A method of wireless communication performed by a user equipment (UE), comprising:
receiving, from a network entity, downlink control information (DCI) in format 1_2 that includes an indicator associated with a first quantity of codepoints that is smaller than a second quantity of activated transmission configuration indicator (TCI) states,
the DCI including a TCI field of m bits,
m being an integer,
the first quantity of the codepoints relating to a subset of the second quantity of the activated TCI states, and
the subset comprising a first 2 m TCI states of the second quantity of the activated TCI states; and
applying a TCI state, from the subset, according to the indicator.
20 . The method of claim 19 , wherein a quantity of the first 2 m TCI states is a same quantity as the first quantity of the codepoints.
21 . The method of claim 20 , wherein the codepoints are based on a control element that activated the activated TCI states.
22 . The method of claim 20 , wherein the first 2 m TCI states are based on a sequential order of the codepoints.
23 . The method of claim 19 , wherein the first 2 m TCI states are based on corresponding indices associated with the activated TCI states.
24 . The method of claim 23 , wherein the corresponding indices are based on a radio resource control (RRC) message that indicated a set of TCI states that includes the activated TCI states.
25 . The method of claim 23 , wherein the first 2 m TCI states are based on a sequential order of the corresponding indices.
26 . The method of claim 19 , wherein the activated TCI states are activated by a control element associated with a single transmit-receive point (TRP) of the network entity.
27 . The method of claim 19 , wherein the activated TCI states are activated by a control element associated with a control resource (CORESET) pool identifier for one of a plurality of transmit-receive points (TRPs) of the network entity.
28 . The method of claim 19 , further comprising:
receiving, from the network entity, an indication that the indicator will include one bit or two bits,
wherein the TCI state is selected from the first 2 m TCI states based on the indication.
29 . The method of claim 28 , wherein the indication is included in a radio resource control (RRC) message.
30 . A method of wireless communication performed by a base station, comprising:
transmitting downlink control information (DCI) in format 1_2 that includes an indicator associated with a first quantity of codepoints that is smaller than a second quantity of activated transmission configuration indicator (TCI) states,
the DCI including a TCI field of m bits,
m being an integer,
the first quantity of the codepoints relating to a subset of the second quantity of the activated TCI states, and
the subset comprising a first 2 m TCI states of the second quantity of activated TCI states; and
applying a TCI state, from the subset, according to the indicator.