Terminal Uplink Timing Control for Multi-TRP Synchronization

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Solution Overview

Problem

In future radio communication systems, controlling uplink transmission to multiple transmission/reception points (TRPs) is challenging, which can degrade communication quality unless appropriate timing advance and synchronization are managed.

Innovation Solution

A terminal is equipped with a transmitting section that sends a UL time synchronization request based on TRP synchronization status and time alignment, and a control section that determines synchronization after a specific period, enabling effective communication with multiple TRPs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If UL transmission is performed to multiple TRPs without appropriate timing control, then communication capacity is increased, but communication quality degrades due to synchronization issues

Engineering Contradiction:
Improvenumber of TRPsVSAvoidcommunication quality
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent segments the timing control mechanism by introducing TRP-specific timing advance values and synchronization requests for each transmission/reception point. This allows independent timing management for each TRP, resolving the contradiction by enabling multi-TRP operation while maintaining individual synchronization accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements a feedback mechanism where the terminal monitors synchronization status per TRP and transmits UL time synchronization requests when desynchronization is detected. This feedback loop ensures timing alignment is maintained across multiple TRPs, allowing increased TRP quantity without sacrificing communication quality.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If timing advance is controlled per TRP, then synchronization accuracy is improved, but system complexity increases

Engineering Contradiction:
Improvesynchronization accuracyVSAvoidtiming control complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent divides timing advance control into TRP-specific parameters, allowing precise synchronization for each TRP. While this segmentation improves accuracy, the patent manages complexity by implementing selective updates only when synchronization status changes, rather than continuous control of all parameters.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The terminal autonomously determines synchronization status and generates timing synchronization requests without requiring continuous network intervention. This self-service approach maintains high synchronization accuracy while reducing the complexity of network-side control mechanisms.

Inventive Principle:
Principle #25Self-service

3Reliability

If synchronization status is monitored continuously, then communication quality is maintained, but terminal processing load increases

Engineering Contradiction:
Improvecommunication qualityVSAvoidterminal processing load
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic monitoring of synchronization status at defined intervals rather than continuous monitoring. This periodic approach maintains communication quality by detecting synchronization degradation when it occurs, while significantly reducing terminal processing load compared to continuous monitoring.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent extracts and monitors only the critical synchronization status parameter rather than all possible communication parameters. This selective monitoring approach maintains communication quality by focusing on the key synchronization metric while minimizing terminal processing requirements.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP4598158A1Terminal, wireless communication method, and base station
Publication Date: 2025.08.06 NTT DOCOMO INC
  • EP4598158A1 patent drawingFigure 1A~1D
  • EP4598158A1 patent drawingFigure 2A~2B
  • EP4598158A1 patent drawingFigure 3

AI summary

A terminal according to an aspect of the present disclosure includes a transmitting section that transmits a UL time synchronization request related to a transmission/reception point (TRP) by using a specific uplink (UL) signal, based on at least one of a synchronization status per the TRP and time alignment establishment per the TRP, and a control section that determines that a plurality of TRPs are synchronized after a specific period of time elapses after transmitting the UL signal. According to an aspect of the present disclosure, even when communication is performed by using a plurality of transmission points, the communication can be appropriately performed.