Indoor Wireless Orientation via Shadow Fading Analysis
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Solution Overview
Problem
Existing GPS-based positioning systems are inaccurate and inefficient for indoor location tracking, especially in noisy environments, making it difficult to quickly and accurately find lost devices.
Innovation Solution
A method and device that determine a reference direction using geomagnetic sensors or user input, filter link quality parameter values to identify shadow fading, and calculate the direction of a lost device based on included angles, providing accurate and efficient orientation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If GPS positioning is used for location tracking, then positioning function is provided, but positioning accuracy is low and cannot be used indoors
Solution Approach 1:
The patent introduces a wireless signal as an intermediary medium between the first device and second device. By measuring the link quality parameter of the wireless signal and analyzing shadow fading patterns, the system can determine the direction and location of the second device indoors without relying on GPS satellites, thus resolving the contradiction between positioning accuracy and indoor usability
Solution Approach 2:
The patent replaces the GPS satellite-based electromagnetic positioning system with a local wireless communication-based positioning system. Instead of relying on satellite signals that cannot penetrate buildings, the system uses local wireless signals and shadow fading analysis to achieve indoor positioning, substituting one electromagnetic system with another that works in the indoor environment
2Measurement precision
If auditory sensation method is used to search for lost device, then device can be located, but searching efficiency is low and easily affected by ambient noise
Solution Approach 1:
The patent replaces the human auditory sensation system with an electronic measurement system. Instead of relying on human ears to detect sounds, the system uses wireless signal strength measurement and shadow fading analysis to objectively determine the direction and location of the lost device, eliminating the limitations of human hearing such as ambient noise interference and low efficiency
Solution Approach 2:
The system implements feedback by continuously measuring the link quality parameter as the first device rotates, identifying the position with greatest shadow fading, and using this information to calculate the direction of the second device. This automated feedback loop enables efficient and accurate location determination without human intervention
3Reliability
If wireless signal strength threshold method is used, then connection status can be monitored, but cannot provide directional information for location search
Solution Approach 1:
The patent segments the 360-degree rotation of the first device into multiple measurement positions, measuring the link quality parameter at each position. By analyzing the pattern of signal strength variations across different orientations, the system can identify the specific direction where shadow fading occurs, thereby recovering the directional information that is lost when using simple threshold-based connection monitoring
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
The solution achieves accurate and efficient indoor orientation, unaffected by ambient noise or obstructions, enabling quick retrieval of lost items.
Implementation Method 1
determining the reference direction for orientation by using a geomagnetic sensor
Implementation Method 2
obtaining a link quality parameter value according to the received wireless signal; determining a position having greatest shadow fading of the first device according to the obtained link quality parameter value
Data Source
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AI summary
Embodiments of the present invention disclose an orientation method, including: determining a reference direction for orientation; when a first device rotates around an obstruction, receiving a wireless signal sent by a second device, and obtaining a link quality parameter value according to the received wireless signal; determining a position having greatest shadow fading of the first device according to the obtained link quality parameter value, and using a pointing direction of the position having greatest shadow fading of the first device as a first pointing direction; and determining, according to an included angle θ1 between the reference direction and the first pointing direction and an included angle θ2 between the reference direction and a second pointing direction, a direction in which the second device is located, where the second pointing direction is a pointing direction of the first device. The embodiments of the present invention further disclose a first device and a system. The present invention can be used to resolve low orientation precision and low efficiency of searching for a second device.