Spread-Spectrum Transceiver Two-Way Ranging for Emergency Locating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing emergency locating systems are impractical in areas without cellular coverage and rely heavily on GPS, which can be unreliable due to infrastructure requirements and signal blocking issues, especially in sparsely populated or obstructed environments.
Innovation Solution
A spread-spectrum transceiver-based system for two-way ranging that allows for communication of distress signals and location calculation without extensive infrastructure, using direct-sequence spread-spectrum encoded messages and layered spreading codes to enable accurate ranging and covert operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If GPS is used for emergency locating, then worldwide coverage is achieved, but the system becomes unreliable in obstructed environments and consumes high power
Solution Approach 1:
The patent replaces GPS satellite-based electromagnetic signal reception with a terrestrial spread-spectrum radio communication system. Instead of relying on space-based signals that penetrate atmosphere and are blocked by obstacles, the invention uses ground-based transceivers communicating via two-way ranging, substituting a mechanical/terrestrial system for a space-based electromagnetic system.
Solution Approach 2:
The patent introduces spread-spectrum transceivers as intermediary devices between the person in distress and the locating system. These transceivers establish direct radio communication links and perform two-way ranging to determine location, acting as mediators that enable locating without direct GPS satellite reception.
2Reliability
If cellular telephones with enhanced 911 are used, then emergency locating capability is provided, but the system requires extensive infrastructure and is unavailable in areas without cellular coverage
Solution Approach 1:
The patent extracts the core locating function from the cellular infrastructure dependency. By using spread-spectrum transceivers that can operate independently of cellular networks, the invention separates emergency locating capability from cellular coverage requirements, enabling operation in remote areas without cellular infrastructure.
Solution Approach 2:
The transceiver unit performs self-service by conducting two-way ranging with locator transceivers to determine its own position. The system is self-contained, requiring no external cellular network infrastructure, and can autonomously establish communication links for locating purposes.
3Measurement precision
If traditional locating systems are used, then location determination is achieved, but accuracy is reduced in sparsely populated or obstructed areas
Solution Approach 1:
The patent changes the fundamental parameters of the locating system by using spread-spectrum modulation and two-way ranging instead of traditional GPS signal reception. This parameter change enables the system to maintain high accuracy in obstructed environments where traditional systems fail, as spread-spectrum signals are more resistant to multipath effects and blockage.
Solution Approach 2:
The system dynamically adapts to environmental conditions by using bidirectional communication for ranging. The locator transceiver and emergency transceiver exchange messages and measure delays, allowing the system to adjust to varying propagation conditions in different environments, whether urban, rural, or obstructed.
Data Source
AI summary
An emergency locating system can include emergency transceivers and locator transceivers. The emergency transceivers can be capable of transmission of spread-spectrum encoded messages, and can be actuated by a user to send a distress message. A locator transceiver can be capable of receiving the distress messages and performing two-way ranging to determine a distance between the locator transceiver and the emergency transceiver.