OOC V2X Synchronization Using Peer Timing Recovery

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Solution Overview

Problem

Existing technologies struggle to maintain accurate synchronization in out of coverage (OOC) vehicle-to-everything (V2X) communications when Global Navigation Satellite System (GNSS) synchronization signals are lost, leading to potential interference and degradation in communication performance.

Innovation Solution

UEs in OOC maintain synchronization by receiving timing information from multiple synchronized peers, applying weighted time averaging based on reliability factors and higher layer parameters to adjust transmission timing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If UEs rely on GNSS synchronization signals for V2X communication, then timing synchronization is maintained under normal conditions, but communication performance degrades when GNSS signals are lost

Engineering Contradiction:
ImproveV2X communication reliabilityVSAvoidinterference from timing uncertainty
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces synchronized peer UEs as intermediary sources to provide timing information when GNSS synchronization is lost. These peer UEs act as mediators between the lost GNSS reference and the UE needing synchronization, allowing timing recovery through received packets from synchronized peers without directly relying on the unavailable GNSS signal.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent implements feedback mechanisms where UEs monitor their synchronization status by detecting timing uncertainty values and error values from received packets. When timing uncertainty exceeds thresholds, the system triggers synchronization recovery procedures, creating a closed-loop feedback system that continuously adapts to synchronization conditions and maintains communication reliability.

Inventive Principle:
Principle #23Feedback

2Productivity

If UEs perform timing adjustments without synchronization, then communication can continue, but timing accuracy deteriorates leading to interference

Engineering Contradiction:
Improvecommunication continuityVSAvoidtiming accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent applies partial action by implementing receive-only periods during which UEs temporarily suspend transmission to focus on receiving and measuring timing information from synchronized peers. This partial suspension of normal operation allows the system to gather sufficient timing data to make accurate adjustments when resuming communication, balancing continuity with accuracy.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent performs preliminary timing measurements and calculations during receive-only periods before resuming normal transmission. By pre-calculating timing adjustments based on received packet timing information and timing uncertainty values, the system ensures that when communication resumes, timing accuracy is already optimized, preventing interference while maintaining continuity.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If UEs enter receive-only period to recover synchronization, then timing accuracy is improved, but communication duration is reduced

Engineering Contradiction:
Improvetiming synchronization accuracyVSAvoidcommunication availability
Core Design Contradiction:
Measurement precisionVSDuration of action of moving object

Solution Approach 1:

The patent implements periodic receive-only periods rather than continuous operation, allowing UEs to periodically recover synchronization while maintaining communication during non-receive periods. This periodic approach balances the need for timing accuracy with the need for continuous communication, ensuring that synchronization is maintained without prolonged interruptions to service.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP3864910B1Cellular vehicle-to-everything out of coverage synchronization
Publication Date: 2025.11.19 QUALCOMM INC
  • EP3864910B1 patent drawingFigure 1
  • EP3864910B1 patent drawingFigure 2
  • EP3864910B1 patent drawingFigure 3

AI summary

Aspects directed towards synchronizing out of coverage (OOC) vehicle-to- everything (V2X) communications are disclosed. In one example, a scheduled entity detects a loss of a synchronization signal associated with a V2X communication by detecting when a timing uncertainty value or error value is greater than a threshold value. Packet timing information is then received in response to the loss of the synchronization signal from at least one user equipment (UE) synchronized with the synchronization signal. The scheduled entity then maintains the V2X communication by performing a timing adjustment based on the packet timing information.