Terminal UL Timing Advance Control Across Multiple TRPs

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Solution Overview

Problem

In future radio communication systems, the control of uplink transmission (UL) in scenarios involving multiple transmission/reception points (TRPs) is challenging due to the need for appropriate timing advance management across different TRPs.

Innovation Solution

A terminal and base station system that determines timing advance for UL transmission based on serving cell configuration information and spatial relation information, enabling precise control of UL transmission through timing advance groups.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple TRPs are configured in a serving cell with timing advance support, then communication capacity and speed are improved, but the complexity of controlling UL transmission and managing timing advance increases

Engineering Contradiction:
Improvecommunication capacityVSAvoidUL transmission control complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the serving cell into multiple timing advance groups (TAGs), each associated with specific TRPs. This segmentation allows independent timing advance management for each TRP, resolving the complexity of controlling UL transmission across multiple TRPs while maintaining high communication capacity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces spatial relation information as an intermediary mechanism to link TRPs with timing advance groups. This intermediary enables the terminal to determine which TAG to apply based on the TRP being accessed, simplifying the control process while supporting multiple TRPs.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If timing advance is applied for each TRP, then transmission timing precision is improved, but the difficulty of determining which timing advance to apply increases

Engineering Contradiction:
Improvetransmission timing precisionVSAvoidtiming advance selection difficulty
Core Design Contradiction:
Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The patent implements feedback mechanisms where the terminal receives indication information from the network about the appropriate TAG to use. This feedback simplifies the selection process while maintaining precise timing advance application for each TRP.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The terminal autonomously determines the appropriate TAG based on the spatial relation information and TRP identification, without requiring complex manual configuration. This self-service approach reduces the difficulty of timing advance selection while preserving timing precision.

Inventive Principle:
Principle #25Self-service

3Manufacturing precision

If spatial relation information is provided for UL transmission, then transmission control accuracy is improved, but the configuration complexity increases

Engineering Contradiction:
Improvetransmission control accuracyVSAvoidconfiguration complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent makes spatial relation information serve multiple functions: it identifies the TRP, determines the associated TAG, and enables accurate timing advance application. This multi-functionality improves transmission control accuracy while avoiding the need for separate configuration mechanisms.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4694398A1Terminal, wireless communication method, and base station
Publication Date: 2026.02.11 NTT DOCOMO INC
  • EP4694398A1 patent drawingFigure 1A~1D
  • EP4694398A1 patent drawingFigure 2
  • EP4694398A1 patent drawingFigure 3A~3B

AI summary

A terminal according to one aspect of the present disclosure includes a receiving section that receives serving cell configuration information, and a control section that determines timing advance to be applied to UL transmission, based on at least one of the serving cell configuration information and whether or not spatial relation information corresponding to the UL transmission is provided or a timing advance group associated with the spatial relation information.