Vehicle-Mounted Communication Timing With Bidirectional Delay Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle-mounted devices experience inaccuracies in time synchronization due to differences in propagation delay times of data transmission in different directions, leading to reduced synchronization accuracy.
Innovation Solution
A vehicle-mounted device and system that store delay time information for both directions of data transmission, allowing for the measurement and correction of propagation delay times using a processing unit and correction unit to perform accurate time synchronization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the average value of propagation delay times in two directions is used for time synchronization, then time synchronization can be performed, but the synchronization accuracy is reduced due to differences in transmission delay times in different directions
Solution Approach 1:
The patent segments the propagation delay time measurement into four distinct delay time components: transmission delay time from external portion to measurement reference position at data reception time in own device, transmission delay time from external portion to measurement reference position at data reception time in other device, transmission delay time from measurement reference position to external portion at data transmission time in own device, and transmission delay time from measurement reference position to external portion at data transmission time in other device. By storing and correcting using these segmented delay time values, the patent achieves more accurate propagation delay time calculation and improves time synchronization accuracy.
2Measurement precision
If delay time information for both transmission directions is stored and used for correction, then time synchronization accuracy is improved, but the device complexity increases due to additional storage and processing requirements
Solution Approach 1:
The patent applies preliminary action by storing delay time information (including transmission delay times in both directions) in advance before time synchronization is performed. The storage unit holds these delay time values ready for correction, so when time synchronization needs to be performed, the correction unit can immediately use the pre-stored delay time information to correct the measured propagation delay time, improving synchronization accuracy without adding complex real-time processing requirements.
Data Source
AI summary
A vehicle-mounted device stores delay time information of a first set and a second set. The first set includes a first transmission delay time from an external portion to a measurement reference position at a data reception time, and a second transmission delay time from an external portion to a measurement reference position at a data reception time in another device. The second set includes a third transmission delay time from a measurement reference position to an external portion at a data transmission time, and a fourth transmission delay time from a measurement reference position to an external portion at a data transmission time in the other device. A propagation delay time between the devices is measured by time synchronization information to and from the other device, the measured propagation delay time is corrected based on the stored delay time information, and time synchronization between the devices is performed.