Asynchronous Wireless Positioning via TDOA Calculation
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Solution Overview
Problem
Current time difference of arrival (TDOA)-based positioning methods require strict synchronization between anchor nodes, making them unsuitable for asynchronous environments in wireless networks.
Innovation Solution
A wireless network-based positioning method that determines the location of a to-be-positioned node by calculating time differences of arrival of a sounding signal at asynchronous anchor nodes using historical information and time information, allowing accurate positioning without requiring synchronization between anchor nodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If TDOA-based positioning method is used, then positioning can be performed with only anchor node synchronization, but it cannot be used in asynchronous environments
Solution Approach 1:
The system performs preliminary actions by having anchor nodes send their identification information and timing data before the actual positioning measurement. The to-be-positioned node stores this preliminary information and uses it to calculate TDOA values, enabling positioning in asynchronous environments where strict synchronization between anchor nodes is not available.
Solution Approach 2:
The to-be-positioned node acts as an intermediary that collects timing information from multiple asynchronous anchor nodes, processes this information by calculating TDOA values relative to a reference anchor node, and determines its own position. This intermediary approach allows the system to handle asynchronous anchor nodes by performing the synchronization calculation at the to-be-positioned node rather than requiring anchor node synchronization.
2Measurement precision
If strict synchronization is ensured between anchor nodes, then TDOA-based positioning can be implemented, but it increases system complexity and is difficult to achieve in many wireless networks
Solution Approach 1:
The to-be-positioned node performs self-service by autonomously calculating the TDOA values using the timing information received from anchor nodes and its own local clock. Instead of requiring the anchor nodes to be strictly synchronized, the to-be-positioned node compensates for timing differences by performing calculations relative to a reference anchor node, thereby eliminating the need for complex inter-anchor synchronization infrastructure.
3Measurement precision
If TOA-based positioning method is used, then positioning can be performed, but strict synchronization is required not only between to-be-positioned node and anchor node but also between anchor nodes
Solution Approach 1:
Instead of requiring anchor nodes to be synchronized with each other (the conventional approach), the invention inverts the approach by having the to-be-positioned node perform the synchronization calculation. The to-be-positioned node calculates TDOA values by comparing arrival times relative to a reference anchor node, thereby inverting who performs the synchronization function and enabling operation in asynchronous networks.
Data Source
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AI summary
The present invention provides a wireless network-based positioning method and positioning apparatus. The positioning method includes: obtaining time information used for determining a current location of a to-be-positioned node, where the time information records times of arrival of a first sounding signal determining time differences of arrival of the first sounding signal at the at least three anchor nodes according to recorded historical information and the time information; and determining the current location of the to-be-positioned node according to locations of the at least three anchor nodes and the time differences of arrival of the first sounding signal at the at least three anchor nodes. By means of the present invention, time differences of arrival of a sounding signal at different anchor nodes can be accurately determined, thereby determining an accurate location of a to-be-positioned node and avoiding synchronization between the anchor nodes.