Dynamic TCI State Beam Switching via DCI
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Solution Overview
Problem
Current wireless communication systems face inefficiencies in dynamically adapting transmission configuration indication (TCI) states to changing channel conditions, leading to suboptimal beam switching operations due to the slow update mechanisms, such as RRC or MAC-CE signaling, which can result in reduced throughput.
Innovation Solution
Implementing a method where a base station transmits DCI to update TCI states dynamically, allowing for frequent adaptation of quasi-collocation relationships between antenna ports, and using subsets of TCI states to indicate beam switching operations, including both data and control beam switching, based on the most significant bit (MSB) of the TCI state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If RRC or MAC-CE signaling is used to update TCI states, then the update mechanism is reliable and standardized, but the update speed is slow and cannot adapt quickly to changing channel conditions
Solution Approach 1:
The patent makes the TCI state update mechanism dynamic by enabling two modes: traditional RRC/MAC-CE signaling for stable conditions, and fast DCI-based signaling for rapidly changing channel conditions. The system dynamically switches between these modes based on beam switching indications, allowing quick adaptation when needed while maintaining reliability of the standardized mechanisms when appropriate.
Solution Approach 2:
The patent segments the TCI state update process into two independent pathways: (1) traditional RRC/MAC-CE based updates for general configuration changes, and (2) fast DCI-based updates specifically for beam switching scenarios. This segmentation allows each pathway to be optimized for its specific use case, with DCI providing rapid updates when beam switching is detected.
2Productivity
If DCI-based dynamic TCI state updates are implemented, then beam switching latency is reduced and throughput is improved, but signaling overhead increases
Solution Approach 1:
The patent applies partial action by implementing DCI-based TCI state updates only in the specific scenario where beam switching is indicated, rather than using DCI for all TCI state updates. The base station determines whether beam switching has occurred and selectively triggers the fast update mechanism only when necessary, avoiding unnecessary DCI overhead while still capturing the performance benefits in relevant scenarios.
3Measurement precision
If frequent TCI state updates are performed to track channel conditions, then beam switching accuracy is improved, but control signaling complexity increases
Solution Approach 1:
The patent introduces beam switching indications as an intermediary mechanism that triggers DCI-based TCI state updates. Rather than continuously updating TCI states or using complex signaling to determine when updates are needed, the system uses beam switching indications as a simple trigger condition. This intermediary simplifies the control logic while enabling accurate tracking of channel conditions through DCI-based updates.
Data Source
AI summary
Transmission configuration indication (TCI) states may be used to indicate beam switching for data beams and/or control beams. A total set of TCI states may be divided into subsets of TCI states. TCI states conveyed via downlink control information (DCI) may thus act as beam switching indications depending on which subset a conveyed TCI state resides. A base station may transmit an indication that such DCI based control beam switching is enabled. Based on whether TCI state (e.g., included in DCI) belongs to a first subset of TCI states or a second subset of TCI states, a wireless device (e.g., that receives the DCI) may trigger a beam switching operation. Beam switching operations may include data beam switching or both data beam switching and control beam switching. The UE may then receive a downlink control channel and a downlink data channel based on the triggered beam switching operation.