Indoor GNSS Tracking via Lower Elevation Satellite Prioritization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional GPS systems struggle to provide accurate and timely location determination in indoor or sheltered environments due to obstructed signals from overhead satellites, making it less effective for mobile communication devices.
Innovation Solution
A method that prioritizes lower elevation satellites for GPS signal reception within indoor facilities by sorting and correlating them first, using assistance data from Wi-Fi or cellular networks, and employing a satellite searching scheme that starts with satellites above a predefined minimum elevation angle of approximately five degrees, followed by higher elevation satellites if necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional GPS methods prioritize higher elevation satellites for signal reception, then signal-to-noise ratio is improved, but location determination accuracy deteriorates in indoor environments
Solution Approach 1:
The patent inverts the conventional satellite selection strategy by prioritizing lower elevation satellites (near horizon) over higher elevation satellites (zenith) when operating in indoor environments. This inversion is based on the observation that signals from lower elevation satellites experience less attenuation through building structures and provide better location determination accuracy in sheltered facilities, directly resolving the contradiction between conventional signal quality metrics and actual positioning performance.
2Reliability
If GPS receivers on mobile devices search for direct overhead satellites, then signal reception is improved, but effectiveness deteriorates within indoor facilities
Solution Approach 1:
The patent implements dynamic satellite selection based on the operational environment. The system adapts its satellite searching strategy by detecting whether the device is in an indoor or outdoor setting and accordingly prioritizing different elevation angles. This dynamic adaptation allows mobile GPS receivers to maintain effectiveness across both outdoor and indoor environments, resolving the contradiction between optimized outdoor performance and indoor versatility.
3Measurement precision
If conventional GPS systems use unobstructed clear vision to overhead satellites, then location determination is improved, but timeliness deteriorates in indoor facilities
Solution Approach 1:
The patent applies preliminary action by pre-sorting satellites according to elevation angles before the actual location determination process begins. When the system detects an indoor environment, it has already prepared the sorted list prioritizing lower elevation satellites, enabling immediate acquisition of the optimal satellite for positioning. This preliminary sorting eliminates the time delay that would otherwise be required to identify suitable satellites during the location fix process, thereby resolving the contradiction between accuracy and timeliness.
Data Source
AI summary
A method and chipset for tracking a global navigation satellite system (GNSS) within the constraints of an indoor facility. The method includes receiving assistance information on the GNSS on a mobile communication system; and sorting orbiting satellites within the GNSS by elevation angles. Additionally, lower elevation satellites are correlated within the GNSS prior to correlating higher elevation satellites.