Terminal TCI State Determination for NR Signal Scheduling

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Solution Overview

Problem

The method of indicating the Transmission Configuration Indication (TCI) state in future radio communication systems, such as New Radio (NR), is not clear, leading to potential reductions in communication quality and throughput.

Innovation Solution

A terminal that receives configuration parameters and indications related to a unified TCI state, and uses this information to determine the appropriate TCI state or quasi-co-location (QCL) assumption for specific downlink signals based on the time period from receiving Downlink Control Information (DCI) to the downlink signal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a unified TCI state is indicated for multiple downlink signals, then device complexity is reduced, but indication clarity deteriorates when time period is short

Engineering Contradiction:

ImproveTCI state management complexityVSAvoidTCI state indication clarity

Core Design Contradiction:

Device complexityVSLoss of information

Solution Approach 1:

The patent segments the TCI state indication process into two distinct paths: one for short time periods (using separate TCI states from different TCI state groups) and another for long time periods (using unified TCI state). This segmentation resolves the contradiction by providing clear indication methods for each time scenario, preventing information loss while maintaining manageable device complexity through structured handling.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces dynamic selection of TCI state application methods based on the time period between DCI and downlink signal. The terminal dynamically determines whether to apply unified TCI state or separate TCI states depending on whether the time period exceeds a threshold. This dynamic approach ensures indication clarity is maintained across varying time conditions while avoiding unnecessary complexity in static configurations.

Inventive Principle:

Principle #15Dynamics

2Loss of information

If separate TCI states are used for different downlink signals, then indication clarity is improved, but device complexity increases

Engineering Contradiction:

ImproveTCI state indication clarityVSAvoidTCI state management complexity

Core Design Contradiction:

Loss of informationVSDevice complexity

Solution Approach 1:

The patent employs dynamic TCI state selection where the terminal adapts its behavior based on the time period. When the time period is long, unified TCI state is applied reducing complexity. When the time period is short, separate TCI states from different groups are used to ensure clarity. This dynamic adaptation resolves the contradiction by applying separate TCI states only when necessary, rather than always.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the TCI state configuration parameter based on the time period threshold. The system transitions between different TCI state application modes (unified vs. separate) depending on the temporal parameter. This parameter-based switching ensures that separate TCI states are applied only when the time condition warrants it, balancing indication clarity with manageable device complexity.

Inventive Principle:

Principle #35Parameter changes

3Speed

If unified TCI state is applied, then processing speed is improved, but communication quality deteriorates when time period is short

Engineering Contradiction:

ImproveSignal processing speedVSAvoidCommunication quality

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The patent introduces dynamic TCI state selection based on time period to resolve the contradiction between processing speed and communication quality. When time period is long, unified TCI state is applied for fast processing. When time period is short, separate TCI states are used to ensure communication quality. This dynamic adaptation ensures both speed and quality are optimized for their respective time conditions.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent segments the time period into two ranges (short and long) with different TCI state application strategies. For short time periods, separate TCI states from different groups are applied to maintain communication quality. For long time periods, unified TCI state is applied to achieve processing speed. This temporal segmentation resolves the contradiction by matching the processing method to the time condition.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentEP4554268A1Terminal, wireless communication method, and base station

Publication Date: 2025.05.14 NTT DOCOMO INC

Figure 1A~1C
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Figure 3A~3B

AI summary

A terminal according to one aspect of the present disclosure includes a receiving section that receives a configuration parameter related to a unified transmission configuration indication (TCI) state, and receives an indication related to the unified TCI state and downlink control information (DCI) for scheduling or triggering a downlink (DL) signal, and a control section that, when at least one TCI codepoint corresponds to a plurality of TCI states and a value of a time period from reception of the DCI to reception of the DL signal is smaller than a threshold, determines a TCI state or QCL assumption to be applied to a specific DL signal, based on the TCI state corresponding to a specific TCI codepoint or the unified TCI state corresponding to an index related to a specific transmission/reception point (TRP). According to one aspect of the present disclosure, application of a TCI state can be appropriately performed.