Beaconing Device Location Estimation Using Multi-Power RF Signals
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Solution Overview
Problem
Existing location tracking methods within buildings, such as radar and GPS, are ineffective due to signal interference and attenuation, and radio signal power level-based methods suffer from reduced accuracy in complex environments.
Innovation Solution
A tracking system that uses a beaconing device transmitting multiple RF signals with different power levels, which are received by anchor devices at known locations, allowing for accurate location calculation through weighted distance estimation, thereby overcoming receiver saturation and multipath effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If radio signal power level attenuation is used for location estimation, then the system can operate within buildings, but the accuracy deteriorates exponentially as signal power decreases due to logarithmic attenuation
Solution Approach 1:
The patent segments the location estimation process by using multiple discrete signal power levels instead of continuous attenuation measurement. The mobile device transmits signals at multiple predetermined power levels, and the system determines distance based on which power level is finally received, creating discrete distance bins that are more robust to signal variations.
Solution Approach 2:
The patent changes the parameter being measured from continuous signal power level (which attenuates logarithmically) to discrete signal transmission attempts at multiple predetermined power levels. This transformation from continuous to discrete measurement reduces the exponential accuracy deterioration caused by logarithmic attenuation.
2Measurement precision
If multiple RF signals with different power levels are transmitted, then location estimation accuracy is improved through weighted distance calculation, but device complexity increases
Solution Approach 1:
The patent makes the mobile device universal by enabling it to transmit signals at multiple predetermined power levels using the same radio frequency interface. This multi-functionality allows the device to adapt its transmission strategy based on distance requirements without adding separate hardware systems.
Solution Approach 2:
The patent uses periodic transmission attempts at different power levels, where the mobile device systematically tries transmission at each predetermined power level in sequence. This periodic action pattern simplifies the complexity by providing a structured, repeatable process for obtaining multiple distance measurements.
3Reliability
If high power signals are used for transmission, then signal reception reliability is improved, but receiver saturation and multipath effects increase
Solution Approach 1:
The patent applies dynamics by making the transmission power level variable and adaptive. Instead of using a fixed high power level, the system dynamically selects from multiple predetermined power levels based on the specific transmission attempt and environmental conditions, optimizing the balance between reliability and avoiding harmful effects.
Solution Approach 2:
The patent uses partial action by transmitting signals at multiple power levels rather than always using maximum power. This allows the system to use just enough power for reliable reception in each specific case, avoiding the excessive power that would cause saturation and multipath effects.
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 system provides reliable and accurate tracking of a person or object within a building by assigning higher weights to signal power levels with lower transmit power, enhancing location estimation accuracy and reducing interference impacts.
Implementation Method 1
applying the property that the power level of a radio signal attenuates at a logarithmic rate over distance
Data Source
AI summary
In one embodiment, a method of estimating location of a mobile beaconing device within a building includes steps: concurrently transmitting from the beaconing device at least first and second signals, which respectively indicates at least first and second transmit power levels thereof; receiving the at least first and second signals by a plurality of anchor devices at different known locations; estimating first distances between the beaconing device and each anchor device as a function of signal power levels of the first signal received by each anchor device, and second distances between the beaconing device and each anchor device as a function of signal power levels of the second signal received by each anchor devices; and calculating an estimated location of the beaconing device as a function of the estimated first distances and second distances.