TCI State Indication for Ambiguity-Free Multi-TRP PDSCH Reception
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Solution Overview
Problem
In communication systems, particularly in 5G and 6G networks, transmission configuration indicator (TCI) state ambiguity leads to degradation in downlink channel reception performance due to unclear TCI states, especially in scenarios involving multiple transmission and reception points (mTRPs).
Innovation Solution
A method and apparatus for a user equipment (UE) to receive downlink control information (DCI) with scheduling information and TCI fields, determining TCI states based on specific codepoints, allowing for dynamic indication of TCI states for physical downlink shared channels (PDSCH) considering channel conditions and scenarios, resolving ambiguity and enhancing reception performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a base station indicates TCI state for each TRP to terminal, then communication services can be provided through multiple transmission and reception points, but TCI state ambiguity occurs and reception performance degrades
Solution Approach 1:
The patent segments the TCI state indication by introducing a TRP-specific indicator field in DCI that separately identifies which TRP each TCI state corresponds to. This segmentation resolves the ambiguity by clearly associating TCI states with specific TRPs, allowing the terminal to accurately recognize which TCI state to use for receiving data from each TRP without confusion.
Solution Approach 2:
The patent introduces an intermediary TRP indicator field as a mediator between the TCI state and the terminal. This intermediary element explicitly links the TCI state to the corresponding TRP, enabling the terminal to resolve the ambiguity by using the TRP indicator as a reference to determine the correct TCI state for each TRP.
2Device complexity
If TCI state indication is simplified, then signaling overhead is reduced, but TCI state ambiguity occurs leading to reception performance degradation
Solution Approach 1:
The patent segments the TCI indication structure into multiple fields: a TCI state field and a TRP-specific indicator field. This segmentation allows the system to maintain relatively simple signaling while resolving ambiguity, as each field serves a specific function and the combination provides complete information for accurate TCI state recognition.
Solution Approach 2:
The patent applies local quality by making the TCI indication adaptive to each TRP through the TRP-specific indicator field. Rather than using a uniform complex indication structure for all TRPs, the system locally adapts the indication by including TRP-specific identifiers only when multi-TRP operation is active, thereby balancing signaling overhead with reception performance.
3Reliability
If dynamic TCI state adaptation is implemented, then reception performance is improved, but signaling complexity and processing overhead increase
Solution Approach 1:
The patent implements dynamic TCI state adaptation through the TRP-specific indicator field in DCI, which allows the terminal to dynamically determine the appropriate TCI state based on the current TRP configuration. This dynamic mechanism improves reception performance by enabling real-time adaptation to changing multi-TRP scenarios while maintaining manageable complexity through standardized field structures.
Solution Approach 2:
The patent changes the parameter structure of DCI by adding the TRP-specific indicator field, which modifies how TCI states are indicated without fundamentally changing the overall DCI framework. This parameter change enables dynamic adaptation to multi-TRP scenarios while keeping processing complexity within acceptable bounds by reusing existing DCI processing mechanisms.
Data Source
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AI summary
Disclosed are a method and apparatus for indicating a TCI state in a communication system. The method of a UE comprises the steps of: receiving, from at least one TRP among a first TRP and a second TRP, DCI including scheduling information, a TCI field, and a TCI selection field of a PDSCH; determining at least one TCI state for receiving the PDSCH on the basis of a rule according to codepoint 11 of the TCI selection field and one or more TCI states indicated by the TCI field; and receiving the PDSCH from the at least one TRP among the first TRP and the second TRP on the basis of the at least one TCI state.