Angle of Arrival Positioning Mitigating Multipath Interference
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Solution Overview
Problem
Conventional RF-based identification and location-finding systems face inaccuracies in indoor and outdoor environments due to multipath phenomena, self-interference, and non-line-of-sight propagation, especially at UHF and higher frequencies, where multipath effects severely impact location determination accuracy.
Innovation Solution
A method and system employing a narrow bandwidth ranging signal and a multi-path mitigation processor, utilizing digital signal processing and software-defined radio technologies to mitigate multipath effects, allowing for accurate tracking and locating of objects in various wireless networks, including LTE, WiMax, and WiFi, without significant incremental cost or infrastructure changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional RF-based location-finding systems operate at UHF and higher frequencies, then data coverage is excellent in urban and indoor environments, but position accuracy deteriorates due to multipath phenomena and non-line-of-sight propagation
Solution Approach 1:
The patent changes the operating frequency parameter from UHF and higher frequencies to VHF and lower frequencies. This parameter change reduces the severity of multipath phenomena while maintaining adequate data coverage, thereby improving position accuracy without completely sacrificing coverage capability
Solution Approach 2:
The patent applies different frequency bands for different operational needs: VHF and lower frequencies are used for location-finding operations where accuracy is critical, while UHF frequencies can be used for data coverage operations. This local quality approach allows the system to optimize for accuracy when performing location determination while maintaining coverage capabilities
2Measurement precision
If narrow-band ranging signals are used at VHF and lower frequencies to reduce multipath effects, then position accuracy improves, but location determination reliability deteriorates due to remaining multipath phenomena impact
Solution Approach 1:
The patent employs dynamic frequency selection where the system can switch between VHF and lower frequencies for reduced multipath effects, and UHF frequencies when data coverage is the priority. This dynamic approach allows the system to adapt to changing environmental conditions and maintain both accuracy and reliability
Solution Approach 2:
The patent creates a multi-functional location-finding system that can operate across multiple frequency bands (VHF, UHF, and lower frequencies). This universal system can select the appropriate frequency band based on operational requirements, making it reliable for both accuracy-critical operations and coverage-critical operations
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 significantly improves the accuracy of RF-based identification and location-finding systems, enabling precise tracking and locating of objects in challenging environments while maintaining portability and compliance with regulatory requirements, such as FCC 911 requirements, by effectively mitigating multipath interference.
Implementation Method 1
a multi-path mitigation processor to determine a phase difference between the first frequency component and the second frequency component of the returned signal
Data Source
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AI summary
Systems and methods for determining user equipment (UE) locations within a wireless network using reference signals of the wireless network are described. The disclosed systems and methods utilize a plurality of in-phase and quadrature (I/Q) samples generated from signals provided by receive channels associated with two or more antennas of the wireless system. Based on received reference signal parameters the reference signal within the signals from each receive channel among the receive channels is identified. Based on the identified reference signal from each receive channel, an angle of arrival between a baseline of the two or more antennas and incident energy from the UE to the two or more antennas is determined. That angle of arrival is then used to calculate the location of the UE. The angle of arrival may be a horizontal angle of arrival and/or a vertical angle of arrival