Unified TCI State Pointers for Low-Latency Multi-TRP Downlink
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing unified TCI state framework in 3GPP Rel-17 does not support efficient association of PDSCH and PDCCH transmissions with multiple unified TCI states for multi-TRP operations, leading to increased signaling overhead and latency in beam management, particularly in scenarios involving WD movement.
Innovation Solution
Explicitly configuring TCI state pointers to associate PDSCH and PDCCH transmissions with multiple unified TCI states, allowing for simplified and efficient multi-TRP operations by determining spatial filters based on these pointers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the existing unified TCI state framework is used for multi-TRP operations, then beam management can be performed, but signaling overhead and latency increase
Solution Approach 1:
The patent segments the TCI state indication into two parts: a first TCI state indicated by MAC CE for common spatial parameters, and a second TCI state indicated by DCI for specific transmission parameters. This segmentation allows different signaling mechanisms to handle different aspects of beam management, reducing overall signaling overhead and latency while maintaining reliability for multi-TRP operations
2Reliability
If multiple unified TCI states are associated with PDSCH and PDCCH transmissions for multi-TRP operations, then communication robustness improves, but signaling overhead increases
Solution Approach 1:
The patent divides the TCI state indication into multiple parts handled by different signaling mechanisms (MAC CE and DCI), where MAC CE carries the first TCI state for common spatial parameters and DCI carries the second TCI state for specific transmission parameters. This segmentation reduces signaling overhead while maintaining communication robustness through multi-TRP operations
Solution Approach 2:
The patent makes the unified TCI state framework universal by enabling it to support both single-TRP and multi-TRP operations through the same mechanism. The first and second TCI states can be used together or separately depending on the transmission scenario, providing multi-functionality that reduces signaling overhead across different operation modes
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
A method, network node and wireless device (WD) for explicit unified transmission configuration indicator (TCI) state index configuration for downlink (DL) transmissions are disclosed. According to one aspect, a method in a network node includes configuring the WD with a radio resource control (RRC) configuration of at least one transmission configuration indicator (TCI) state pointer, the at least one TCI state pointer being used to indicate an association between at least one scheduled physical downlink shared channel (PDSCH) transmission and at least one joint/downlink TCI state. The method also includes transmitting first and second downlink control information (DCI), the first DCI configured to one of activate and indicate a pair of unified TCI states, the second DCI configured to schedule a first PDSCH and a second PDSCH.