Satellite Selection for A-GPS Location Accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current A-GPS systems face challenges in efficiently selecting optimal satellites for location determination, leading to prolonged acquisition times, power consumption issues, and inaccurate position estimates due to limited satellite visibility and geometry, especially in scenarios with large location uncertainty.
Innovation Solution
A method and system that determine an approximate boundary for a wireless device's location and select an optimum set of satellites based on visibility or dilution of precision (DOP) at predetermined points on the boundary, providing assistance data to improve satellite acquisition and location accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the system monitors all visible satellites for location determination, then location accuracy is improved, but power consumption increases and acquisition time is prolonged
Solution Approach 1:
The patent extracts and selects only the optimal subset of satellites from the complete visible satellite set. The system determines an approximate boundary for the wireless device's location and selects satellites based on visibility or dilution of precision (DOP) metrics at predetermined points on the boundary, thereby extracting only the necessary satellites needed for accurate location determination without processing all visible satellites.
Solution Approach 2:
The patent applies local quality by evaluating satellite characteristics at specific locations (predetermined points on the boundary) rather than uniformly across all areas. The system determines satellite optimality based on local visibility and DOP conditions at these specific points, allowing differentiated satellite selection tailored to the local geometric conditions at each boundary point.
2Measurement precision
If the system selects satellites based on comprehensive boundary analysis, then location accuracy is improved, but system complexity increases
Solution Approach 1:
The patent segments the location uncertainty area into manageable parts by determining an approximate boundary and selecting predetermined points on that boundary. This segmentation approach divides the complex problem of satellite selection over a large area into discrete evaluation points, making the system more tractable while maintaining accuracy.
Solution Approach 2:
The patent performs preliminary action by determining the approximate boundary and selecting optimal satellites before actual location determination. The system pre-calculates which satellites will be optimal based on boundary analysis and DOP metrics, so that when location determination is needed, the device already has a prepared list of optimal satellites to monitor, reducing real-time computational complexity.
3Reliability
If the system uses traditional satellite selection methods, then acquisition time is prolonged, but reliability is maintained
Solution Approach 1:
The patent applies dynamics by making the satellite selection adaptive to the device's location uncertainty characteristics. The system dynamically determines the approximate boundary based on the device's known location information and adjusts the satellite selection accordingly. This dynamic approach allows the system to quickly adapt to different uncertainty scenarios and select the most appropriate satellites for rapid acquisition while maintaining reliability.
Data Source
AI summary
A system and method for determining a set of satellites for which assistance data may be provided to a wireless device. A boundary for an approximate area in which the wireless device is located may be determined and one or more sets of satellites may be determined as a function of the boundary. An optimum set of satellites from the one or more sets of satellites may then be determined using a satellite selection function on the one or more sets of satellites at predetermined points substantially on the boundary.