PDSCH TCI State Determination via Segmented DCI Fields
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Solution Overview
Problem
In wireless communication systems, the limited TCI state indication field in DCI prevents terminals from determining the correct TCI state for each PDSCH, thereby hindering the achievement of expected diversity gain due to unclear beam and TRP configurations for multiple PDSCHs carrying the same data.
Innovation Solution
The method involves determining and indicating the TCI state for each PDSCH through DCI, allowing terminals to accurately identify the TCI state applied to each PDSCH based on the beam and TRP used for transmission, enabling flexible switching between multiple TCI states and improving diversity gain with reduced signaling overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the TCI state indication field in DCI is used to indicate TCI states for multiple PDSCHs, then the terminal can determine the correct TCI state for each PDSCH, but the limited number of bits in the TCI state indication field cannot support indicating TCI states for a large number of PDSCH repetitions
Solution Approach 1:
The patent divides the TCI state indication into multiple parts: a first TCI state indication field in DCI for indicating a first TCI state, and a second TCI state indication field (separate from DCI) for indicating a second TCI state. This segmentation allows the system to indicate TCI states for multiple PDSCHs without requiring an excessively large TCI state indication field in DCI, thus resolving the contradiction between determination accuracy and signaling overhead.
2Reliability
If multiple TCI states are indicated for multiple PDSCHs, then diversity gain can be achieved, but the terminal cannot determine which TCI state is used for each PDSCH when the number of PDSCH repetitions is large
Solution Approach 1:
The patent employs feedback mechanisms where the network device configures multiple TCI states and indicates them through separate fields, allowing the terminal to correctly map TCI states to specific PDSCHs. The terminal can then provide feedback (ACK/NACK) to confirm successful reception, enabling the network to verify whether the diversity gain was achieved and adjust configurations accordingly.
3Device complexity
If the TCI state indication field indicates only a limited number of TCI states, then the DCI structure remains simple, but the terminal cannot achieve expected diversity gain for multiple PDSCHs carrying the same data
Solution Approach 1:
The patent adds another dimension to TCI state indication by introducing a second TCI state indication field separate from the DCI structure. This dimensional expansion allows the system to indicate more TCI states without complicating the original DCI structure, thus maintaining simplicity while improving downlink transmission reliability through enhanced diversity gain.
Data Source
AI summary
A method for downlink data transmission and related products are provided. The method includes: a terminal receives downlink control information (DCI) for scheduling multiple physical downlink shared channels (PDSCHs), wherein the DCI contains transmission configuration indicator (TCI) state indication; and the terminal determines a TCI state which is applied to each of the multiple PDSCHs according to at least one TCI state indicated by the TCI state indication.