Terminal TCI State Timing for Accurate QCL Determination

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Solution Overview

Problem

In future radio communication systems, the information related to quasi-co-location (QCL) is often indefinite, leading to potential communication quality reduction and throughput reduction.

Innovation Solution

A terminal and base station are designed to receive TCI state information for multiple channels and apply a specific TCI state after a defined time from downlink control information, ensuring appropriate determination of QCL.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the terminal applies TCI state information immediately upon reception, then the response speed is improved, but the QCL determination accuracy deteriorates due to insufficient processing time

Engineering Contradiction:

Improveresponse speedVSAvoidQCL determination accuracy

Core Design Contradiction:

SpeedVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by introducing a timing advance mechanism where the terminal is configured to apply TCI state information after a predetermined time period from reception. This advance preparation of timing parameters ensures that the terminal has sufficient processing time to accurately determine QCL relationships while maintaining efficient response characteristics.

Inventive Principle:

Principle #10Preliminary action

2Measurement precision

If the terminal waits for a predetermined time before applying TCI state information, then the QCL determination accuracy is improved, but the communication latency increases

Engineering Contradiction:

ImproveQCL determination accuracyVSAvoidcommunication latency

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies parameter changes by dynamically adjusting the timing parameter (predetermined time period) based on different communication scenarios and requirements. The terminal can be configured with different time offsets depending on the specific channel conditions, TCI state type, and communication priority, thereby optimizing the balance between accuracy and latency for each scenario.

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If the terminal uses indefinite QCL information, then the system flexibility is improved, but the communication quality deteriorates

Engineering Contradiction:

Improvesystem flexibilityVSAvoidcommunication quality

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies feedback mechanisms where the terminal reports back the applied TCI state information and QCL determination results to the network side. This feedback loop enables the network to verify the accuracy of QCL determination and adjust future TCI state assignments accordingly, thereby maintaining high communication quality while preserving system flexibility through adaptive feedback-based optimization.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS12501449B2Terminal, radio communication method, and base station

Publication Date: 2025.12.16 NTT DOCOMO INC

AI summary

A terminal according to one aspect of the present disclosure includes a receiving section that receives TCI state information indicating a plurality of transmission configuration indication (TCI) states applicable to multiple types of channels and that receives first downlink control information indicating one TCI state of the plurality of TCI states, and a control section that applies the one TCI state to a first signal after timing at which specific time passes from any one of the first downlink control information and a first uplink channel based on the first downlink control information. According to one aspect of the present disclosure, it is possible to appropriately determine information related to QCL.