Virtual Positioning Reference for Unsynchronized Radio Signals
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Solution Overview
Problem
Existing vehicle navigation systems face challenges in self-localization using unsynchronized terrestrial radio signals, as calculating transmitter clock offsets and local clock errors is computationally expensive and requires stable clock references, which are often impractical for portable and autonomous vehicles.
Innovation Solution
A method that establishes a virtual positioning reference by analyzing predictably repeated code words from terrestrial transmitters, allowing the vehicle to determine its position without calculating transmitter clock offsets, leveraging the stability of the transmitter clock for accurate localization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If transmitter clock offsets and local clock errors are calculated for accurate positioning, then positioning accuracy is improved, but computational complexity and resource usage increase
Solution Approach 1:
The patent creates a virtual reference receiver that copies the functionality of a real reference receiver. By simulating the reference receiver's clock and processing, the system eliminates the need to calculate transmitter clock offsets and local clock errors, reducing computational complexity while maintaining positioning accuracy through the virtual reference framework
Solution Approach 2:
The virtual reference receiver acts as an intermediary between the mobile receiver and the unsynchronized terrestrial transmitters. It mediates the timing relationships by maintaining a simulated reference clock, allowing the mobile receiver to determine position without directly calculating complex clock offsets between multiple unsynchronized transmitters
2Reliability
If stable clock references are used for positioning calculations, then positioning reliability is improved, but device portability and autonomy are reduced
Solution Approach 1:
The mobile receiver performs self-service by creating and maintaining its own virtual reference receiver with a simulated clock. Instead of relying on external stable clock references or synchronized transmitters, the system generates its own reference framework, enabling portable and autonomous operation without sacrificing positioning reliability
Solution Approach 2:
The system copies the essential functionality of a reference receiver into a virtual implementation that runs locally on the mobile device. This virtual reference contains a simulated clock that replicates reference timing behavior, providing reliable positioning calculations without requiring physical stable clock hardware or external synchronization
3Measurement precision
If multiple synchronized transmitters are used for positioning, then positioning accuracy is improved, but availability of suitable transmitters is reduced
Solution Approach 1:
The patent copies the reference receiver functionality into a virtual implementation that can work with any terrestrial transmitter, synchronized or unsynchronized. The virtual reference receiver simulates the timing relationships, allowing the system to use opportunistic unsynchronized transmitters (TV, radio, cellular) as if they were synchronized, greatly expanding transmitter availability while maintaining positioning accuracy
Solution Approach 2:
The system changes the fundamental parameter of transmitter synchronization from a requirement to an irrelevant characteristic. By using a virtual reference receiver with a simulated clock, the system can process signals from unsynchronized transmitters and correctly determine timing relationships, making the positioning system adaptable to any available transmitter type
Data Source
AI summary
Methods and systems are disclosed for radio positioning of a vehicle using a virtual positioning reference established by logging a known position of the vehicle together with a local time that a first instance of a predictably repeated code word is received from an opportunistic terrestrial radio transmitter. During movement of the vehicle to a second, unknown position, a local clock is used to determine the time difference between when the virtual positioning reference is predicted to receive a second instance of the code word and when the vehicle actually receives the second instance of the code word, thereby providing positioning information when traditional navigation signals such as GPS are not available. The radio positioning information is then used to initiate an action such as recording the location information for future retrieval by a user, and/or controlling the movements of an autonomous vehicle.