Sidelink Transmission Timing Synchronization for Remote and Relay UEs

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Solution Overview

Problem

The transmission timing issue in Device-to-Device (D2D) or Vehicle-to-Everything (V2X) communication systems when a remote UE and a relay UE operate in different sidelink transmission modes causes communication disruptions.

Innovation Solution

A method where a remote UE, operating in sidelink transmission mode 2, receives a timing advance (TA) value from a relay UE operating in mode 1, determines its transmission timing by applying the TA to the sidelink synchronization signal reception timing, and adjusts its timing accordingly to synchronize with the relay UE, ensuring smooth communication by aligning subframe boundaries.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a remote UE operates in sidelink transmission mode 2 and a relay UE operates in mode 1, then device-to-device communication can be established with extended coverage, but transmission timing mismatch occurs causing communication disruptions

Engineering Contradiction:
Improvesidelink transmission mode flexibilityVSAvoidcommunication continuity
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The remote UE dynamically adjusts its transmission timing parameters by applying a timing advance value received from the relay UE. This parameter change aligns the remote UE's subframe boundaries with those of the relay UE, resolving the timing mismatch that occurs when operating in different sidelink transmission modes (mode 2 for remote UE, mode 1 for relay UE) and ensuring continuous reliable communication

Inventive Principle:
Principle #35Parameter changes

2Area of stationary object

If different sidelink transmission modes are used for remote and relay UEs, then network coverage can be extended, but transmission timing alignment is lost

Engineering Contradiction:
Improvenetwork coverage areaVSAvoidtiming alignment precision
Core Design Contradiction:
Area of stationary objectVSManufacturing precision

Solution Approach 1:

The relay UE provides feedback to the remote UE in the form of a timing advance value, which indicates the timing adjustment needed for the remote UE to align its transmissions with the relay UE's timing. This feedback mechanism enables the remote UE to operate in mode 2 (extended coverage) while maintaining precise timing alignment through continuous timing adjustments based on the received feedback

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3627915B1Method and device for transmitting side link signal in wireless communication system
Publication Date: 2022.11.02 LG ELECTRONICS INC
  • EP3627915B1 patent drawingFigure 1(a)~1(b)
  • EP3627915B1 patent drawingFigure 2
  • EP3627915B1 patent drawingFigure 3~4

AI summary

One embodiment of the present invention relates to a method for transmitting a side link signal in a wireless communication system by a UE operating in side link transmission mode 2, the method comprising: a step of receiving a predetermined signal by the UE; and a step of transmitting a side link signal on the basis of a first timing which is determined on the basis of the predetermined signal, wherein the first timing is determined differently depending on whether or not the UE establishes a connection with a relay UE.