Pulsed Wireless Location System for GPS-Denied Positioning
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Solution Overview
Problem
Current radio positioning/navigation systems, such as GNSS, are ineffective in providing accurate and consistent positioning data within line-of-sight barriers due to multi-path signal propagation, the 'near-far' problem, and high power consumption, limiting their use in environments like forests, canyons, and buildings where direct line-of-sight is obstructed.
Innovation Solution
Integration of Pulsed Wireless Location System (PWLS) with GNSS to provide positioning/navigation data, using non-coplanar PWLS anchors and transceiver/processors that communicate with each other or a cloud server to determine precise location, overcoming multi-path and 'near-far' issues, and enabling data integration with GNSS systems for seamless coordination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If GNSS signals are used for positioning, then positioning accuracy is improved in direct line-of-sight conditions, but positioning reliability deteriorates within line-of-sight barriers due to multi-path propagation and signal blockage
Solution Approach 1:
The system segments the positioning function into two independent subsystems: GNSS for open-sky positioning and PWLS for barrier-based positioning. Each subsystem operates autonomously in its optimal environment, with the GNSS receiver handling line-of-sight satellite signals and the PWLS transceiver handling pulsed wireless signals from anchors, thereby resolving the contradiction between accuracy in open conditions and reliability in barrier conditions
Solution Approach 2:
The system changes the operational parameters of the positioning system based on environmental conditions. When GNSS signals are available, the system uses satellite-based ranging with meter-level accuracy. When barriers block GNSS signals, the system transitions to PWLS using ultra-wideband pulsed signals with sub-meter accuracy, thereby maintaining both accuracy and reliability across different environments
2Adaptability or versatility
If traditional radio positioning systems operate within line-of-sight barriers, then positioning coverage is improved, but measurement precision deteriorates due to multi-path signal propagation
Solution Approach 1:
The PWLS uses periodic pulsed transmissions instead of continuous signals. The transceiver emits short, periodic pulses and measures the time of arrival at anchors, which eliminates multi-path interference since only the direct pulse path is measured. This periodic pulsed action enables precise positioning within barriers by covering the entire barrier region while maintaining sub-meter precision
Solution Approach 2:
The system replaces traditional continuous radio wave propagation mechanics with pulsed time-of-flight measurement mechanics. Instead of relying on continuous signal strength or phase information that suffers from multi-path effects, the system uses precise timing of discrete pulses to measure distance, substituting the measurement mechanism to achieve both coverage and precision within barriers
3Duration of action of moving object
If continuous signal transmission is used for positioning, then positioning continuity is improved, but energy consumption increases
Solution Approach 1:
The PWLS transceiver operates in periodic pulse mode rather than continuous transmission. The device transmits short pulses at intervals and remains in low-power state between pulses, yet maintains positioning continuity by rapidly exchanging pulses with multiple anchors. This periodic operation achieves both continuous positioning capability and low power consumption for handheld devices
Solution Approach 2:
The system performs preliminary synchronization and anchor selection before actual positioning. The transceiver pre-establishes communication with multiple anchors and caches their positions, so that during operation it only needs to exchange brief pulses rather than maintaining continuous high-power communication, thereby achieving positioning continuity with minimal energy expenditure
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
Enables accurate, sub-meter positioning and navigation within line-of-sight barriers and in direct line-of-sight conditions, reducing power consumption and enhancing the practicality of radio positioning/navigation systems for various applications.
Implementation Method 1
The transceiver/processor uses the measured angles and/or time of flight to determine its three-dimensional (3D) position
Data Source
AI summary
This invention describes a Spatial Intelligence System that provide radio positioning/navigation with additional spatial data in support of automation, machine learning and inference-based systems. More specifically and in particular, the present invention, is such a radio positioning/navigation system that integrates, correlates with or obviates the need of the global navigation satellite systems (GNSS) with a Pulsed Wireless Location System (PWLS) to provide positioning/navigation/timing data either within a line-of-sight barrier using an ad-hoc coordinate system, a direct line of sight of GNSS beacon geographic coordinate system or a ad-hoc translation to geographic coordinate system. The system generically offers the ability to use a low cost tag or location device with anchor processing or a higher cost, higher capability tag or location device with local processing simultaneously.