Transmission configuration indicator (TCI) chain enhancements for new radio systems
This disclosure describes an apparatus comprising a memory to store downlink (DL) transmission configuration indicator (TCI) state chain information, and a processing circuitry, coupled with the memory, to retrieve the DL TCI state chain information from the memory, wherein the DL TCI state information includes an indication of a source reference signal (RS) for a synchronization signal block (SSB) associated with a physical cell identifier that is different from an identifier of a serving cell, and monitor an SSB based on the DL TCI state chain information.
1 . An apparatus of a user equipment (UE), the apparatus comprising:
memory to store transmission configuration indicator (TCI) chains corresponding to a unified TCI framework, the TCI chains including a downlink TCI chain (DL TCI chain) and an uplink TCI chain (UL TCI chain), wherein:
individual ones of the DL TCI chain and the UL TCI chain comprise a synchronization signal block (SSB) and one or more channel state information reference signal (CSI-RS) resources; and
the SSB of the DL TCI chain is associated with a physical cell identifier that is different from an identifier of a serving cell; and
processing circuitry, coupled with the memory, to:
receive, from the memory, the TCI chains;
for TCI state switching, based on the TCI chain having no more than four reference signals, consider two of the four reference signals to be quasi-co-located (QCLed); and
encode or decode signals for wireless communication based on the TCI chains.
2 . The apparatus of claim 1 , the processing circuitry to further use the SSB of the DL TCI chain as a source reference signal (RS).
3 . The apparatus of claim 1 , wherein the SSB of the UL TCI chain is associated with a physical cell identifier that is different from an identifier of a serving cell.
4 . The apparatus of claim 3 , the processing circuitry to further use the SSB of the UL TCI chain as a source reference signal (RS).
5 . The apparatus of claim 1 , the processing circuitry to further, perform transmission reception point (TRP)-specific beam failure detection (BFD) in a time division multiplexed (TDM) manner.
6 . The apparatus of claim 1 , further including a radio frequency front end coupled to the processing circuitry.
7 . The apparatus of claim 6 , further including one or more antennas coupled to the processing circuitry to send and to receive wireless signals.
8 . One or more non-transitory computer-readable media storing instructions to cause, upon execution of the instructions by one or more processors of a User Equipment (UE), the UE to:
store, in a memory of the UE, transmission configuration indicator (TCI) chains corresponding to a unified TCI framework, the TCI chains including a downlink TCI chain (DL TCI chain) and an uplink TCI chain (UL TCI chain), wherein:
individual ones of the DL TCI chain and the UL TCI chain comprise a synchronization signal block (SSB) and one or more channel state information reference signal (CSI-RS) resources; and
the SSB of the DL TCI chain is associated with a physical cell identifier that is different from an identifier of a serving cell;
retrieve, from the memory of the UE, the TCI chains;
for TCI state switching, based on the TCI chain having no more than four reference signals, consider two of the four reference signals to be quasi-co-located (QCLed); and
encode or decode signals for wireless communication based on the TCI chains.
9 . The one or more non-transitory computer-readable media of claim 8 , the instructions to further cause, upon execution of the instructions by the one or more processors, the UE to further use the SSB of the DL TCI chain as a source reference signal (RS).
10 . The one or more non-transitory computer-readable media of claim 8 , wherein the SSB of the UL TCI chain is associated with a physical cell identifier that is different from an identifier of a serving cell.
11 . The one or more non-transitory computer-readable media of claim 10 , the instructions to further cause, upon execution of the instructions by the one or more processors, the UE to further use the SSB of the UL TCI chain as a source reference signal (RS).
12 . The one or more non-transitory computer-readable media of claim 8 , the instructions to further cause, upon execution of the instructions by the one or more processors, the UE to further, perform transmission reception point (TRP)-specific beam failure detection (BFD) in a time division multiplexed (TDM) manner.
13 . A method to be performed at a User Equipment (UE), the method including:
storing, in a memory of the UE, transmission configuration indicator (TCI) chains corresponding to a unified TCI framework, the TCI chains including a downlink TCI chain (DL TCI chain) and an uplink TCI chain (UL TCI chain), wherein:
individual ones of the DL TCI chain and the UL TCI chain comprise a synchronization signal block (SSB) and one or more channel state information reference signal (CSI-RS) resources; and
the SSB of the DL TCI chain is associated with a physical cell identifier that is different from an identifier of a serving cell;
retrieving, from the memory of the UE, the TCI chains;
based on the TCI chain having no more than four reference signals, considering two of the four reference signals to be quasi-co-located (QCLed); and
encoding or decoding signals for wireless communication based on the TCI chains.
14 . The method of claim 13 , further including use the SSB of the DL TCI chain as a source reference signal (RS).
15 . The method of claim 13 , wherein the SSB of the UL TCI chain is associated with a physical cell identifier that is different from an identifier of a serving cell.
16 . The method of claim 15 , further including using the SSB of the UL TCI chain as a source reference signal (RS).
17 . The method of claim 15 , further including performing transmission reception point (TRP)-specific beam failure detection (BFD) in a time division multiplexed (TDM) manner.