Clock Drift Mitigation in Wireless Ranging via Snoop Timing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Clock drift between communication devices in wireless communication systems leads to degradation in performance and missed distance measurement transmissions, as local clocks of different devices drift, causing mismatches in determining the start and end times of scheduled time periods for distance measurements.
Innovation Solution
A method and apparatus that generate and transmit range measurement packets with timing information to adjust timers in other communication devices, ensuring synchronization and accurate estimation of start times and departure times for range measurement signal exchange sessions, using integrated circuits and timers to manage and synchronize timing information across devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If communication devices use local clocks for timing, then each device can independently determine transmission times, but clock drift causes timing mismatches and missed measurements
Solution Approach 1:
The patent implements a feedback mechanism where timing information from transmitted packets is used to adjust local timers. Devices monitor the timing of received packets and adjust their local clock timing based on the difference between expected and actual arrival times, creating a closed-loop synchronization system that compensates for clock drift
Solution Approach 2:
The patent uses timing information embedded in transmitted packets as an intermediary to synchronize clocks between devices. Instead of direct clock comparison, devices exchange timing data through packets, which serve as a mediator carrying synchronization information across the communication channel
2Productivity
If devices transmit distance measurement signals during scheduled time periods, then distance measurements can be performed, but clock drift causes devices to miss transmissions due to mismatched timing
Solution Approach 1:
The patent performs preliminary timing adjustments by adjusting local timers based on timing information from previously received packets before the actual distance measurement transmissions occur. This advance synchronization ensures that devices are properly aligned in time when the scheduled measurement periods begin
Solution Approach 2:
The system continuously monitors timing discrepancies and adjusts local timers based on feedback from received packets, ensuring that devices remain synchronized throughout the measurement process and do not miss transmissions
Data Source
AI summary
A first communication device generates a range measurement packet (or a packet that includes a probe response frame, a TIM frame, etc.) associated with a range measurement signal exchange session between the first communication device and a second communication device. The first communication device records a time value of a first timer corresponding to a time of transmission of the packet, and includes timing information corresponding to the recorded time value in the packet. The first communication device transmits the packet to the second communication device. The timing information in the packet is useable by a third communication device to adjust time values corresponding to a second timer, which the third communication device includes.