GNSS Synchronization for LTE D2D Terminals
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Solution Overview
Problem
Existing LTE R12 D2D communication systems face issues with synchronization, leading to resource allocation misalignment and communication failures when terminals are outside network coverage, causing asynchronization among receiving terminals.
Innovation Solution
The method involves using a GNSS clock to determine the transmission timeslot and synchronization information sending moments, with terminals sending sidelink synchronization information to synchronize with each other, ensuring consistent timing and high precision, thereby avoiding resource allocation misalignment and communication failures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If terminals beyond network coverage area serve as independent synchronization sources using local clocks, then terminals can perform D2D communication without network coverage, but asynchronization occurs between different synchronization sources causing resource allocation misalignment and communication failures
Solution Approach 1:
The patent introduces GNSS satellite system as an intermediary synchronization source that all terminals beyond network coverage can access. Instead of allowing each terminal to use its own local clock as an independent synchronization source (which causes asynchronization), the GNSS system serves as a common mediator that provides unified timing reference to all terminals, thereby maintaining synchronization consistency while enabling D2D communication beyond network coverage.
2Ease of operation
If multiple synchronization sources operate independently beyond network coverage, then communication can be maintained without base station, but resource allocation misalignment occurs due to asynchronization
Solution Approach 1:
The GNSS satellite system acts as an intermediary that provides common timing reference to all terminals operating independently beyond network coverage. This mediator ensures that resource allocation across different terminals remains synchronized, preventing resource allocation misalignment and maintaining communication efficiency while preserving the independence from network coverage.
3Extent of automation
If terminals use local clocks for synchronization beyond coverage area, then they can autonomously determine transmission timeslots, but asynchronization causes communication failures
Solution Approach 1:
The patent uses GNSS satellite system as an intermediary that enables terminals to autonomously determine transmission timeslots while maintaining synchronization. Each terminal can independently acquire GNSS timing information and autonomously calculate its transmission timeslot based on this common reference, achieving both automation and reliability simultaneously.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach ensures consistent transmission timeslots and synchronization among terminals, improving communication performance and preventing resource allocation misalignment and communication failures caused by asynchronization.
Implementation Method 1
determining, according to a GNSS clock, a transmission timeslot corresponding to a current moment in a D2D communications system
Data Source
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AI summary
A synchronous communication method is provided. The method includes: obtaining, by a first terminal, first configuration information, where the first configuration information includes a first parameter; determining, by the first terminal according to a global navigation satellite system GNSS clock, a transmission timeslot corresponding to a current moment in a device-to-device D2D communications system; determining, by the first terminal according to the transmission timeslot and the first parameter, whether the current moment is a synchronization information sending moment; and if the current moment is the synchronization information sending moment, sending, by the first terminal, sidelink synchronization information at the synchronization information sending moment, where the sidelink synchronization information carries indication information, the sidelink synchronization information is used to synchronize a second terminal with the first terminal, and the indication information is used to indicate, to the second terminal, that the first terminal is a synchronization source that uses the GNSS clock.