Hybrid Positioning Using Satellite and Cellular Signal Merging
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Solution Overview
Problem
In urban environments with limited satellite visibility, such as tall buildings, satellite positioning systems (SPS) struggle to determine position, velocity, and time due to receiving signals from fewer than four satellites, leading to inaccurate or unreliable navigation solutions.
Innovation Solution
A method where a mobile station acquires a first portion of non-pseudorange measurements during a first epoch and subsequently uses additional information, like ephemeris and almanac data, to compute a navigation solution using techniques like Advanced Forward Link Trilateration, enabling improved accuracy and position determination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a receiver uses only SPS signals for positioning, then the system remains simple, but the receiver cannot compute a position solution in urban environments with limited satellite visibility
Solution Approach 1:
The patent combines SPS signals with wireless communication system signals (such as cellular base station signals) to create a hybrid positioning system. This merging allows the receiver to use both satellite and terrestrial signals, enabling position computation in urban environments where satellite visibility is limited, while maintaining reasonable system complexity by integrating with existing wireless infrastructure.
Solution Approach 2:
The positioning system is designed to work with multiple signal sources (SPS satellites and wireless communication base stations) and can operate in various environments (open sky and urban canyons). This multi-functionality allows the same receiver to compute positions using different signal combinations depending on availability, enhancing adaptability without requiring separate specialized systems.
2Ease of operation
If a receiver acquires signals from fewer than four SVs, then the receiver can still operate in limited visibility environments, but the receiver cannot resolve all four variables of position and time
Solution Approach 1:
The receiver merges measurements from fewer than four SPS satellites with measurements from wireless communication base stations. This combination provides additional pseudorange measurements needed to resolve all four position and time variables, enabling reliable positioning in environments with limited satellite visibility while maintaining operational simplicity.
Solution Approach 2:
Wireless communication base stations serve as intermediary elements that provide additional measurement sources. These base stations act as intermediate reference points between the receiver and the final position solution, filling the gap when direct satellite measurements are insufficient to resolve all position and time variables.
3Adaptability or versatility
If timing information is not synchronized between base stations and SPS signals, then the system can work with different network standards, but time precision and position accuracy deteriorate
Solution Approach 1:
The system uses feedback mechanisms where the receiver processes measurements from both SPS and wireless communication signals, estimates position and time, and iteratively refines the solution. This feedback loop allows the system to compensate for timing asynchronism between different network standards, maintaining measurement precision while working with unsynchronized base stations and SPS signals.
Data Source
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AI summary
The subject matter disclosed herein relates to positioning systems and location determination using measurement stitching.