Distributed GNSS Positioning for Indoor Femtocells
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Solution Overview
Problem
Determining the location of femtocells within buildings is challenging due to the lack of sufficient satellite vehicle signals, leading to inaccurate or unreliable positioning, especially when multiple femtocells are deployed in close proximity.
Innovation Solution
A method and system that utilize GNSS pseudo range measurements and Observed Time Difference Of Arrival (OTDOA) measurements from fixed radio beacons to determine the location of femtocells, sharing a common time reference and scheduling location measurements to improve accuracy, even when individual femtocells cannot receive signals from enough satellite vehicles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If femtocells are deployed inside buildings to improve coverage, then radio coverage is improved, but location determination becomes unreliable due to insufficient satellite signals
Solution Approach 1:
The patent combines location measurements from multiple femtocells to determine individual femtocell locations. By merging measurement data from neighboring femtocells that can receive satellite signals, the system achieves reliable location determination even when individual femtocells are in signal-deficient environments inside buildings.
Solution Approach 2:
The patent uses neighboring femtocells as intermediaries to obtain location information. Instead of relying directly on satellite signals at each femtocell, the system uses measurements from adjacent femtocells that have better signal access, acting as mediators to provide location data for femtocells in poor signal areas.
2Productivity
If multiple femtocells are deployed in close proximity to increase throughput, then network capacity is improved, but location measurement accuracy deteriorates due to poor satellite signal geometry
Solution Approach 1:
The patent merges location measurements from multiple femtocells to overcome the geometric dilution of precision problem. By combining measurements from neighboring femtocells at different locations, the system reconstructs accurate location information even when individual femtocells experience poor satellite signal geometry due to close proximity deployment.
3Ease of manufacture
If femtocells are deployed in unplanned locations to ease deployment, then ease of installation is improved, but location authorization becomes difficult to verify
Solution Approach 1:
The patent enables femtocells to self-determine their locations through collaborative measurements with neighboring femtocells. This self-service capability allows automatically determined locations to be used for authorization verification, eliminating the need for manual site surveys while maintaining the ability to verify geographic licensing compliance.
Data Source
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AI summary
Method and apparatus for determining locations of static devices are disclosed. The method includes identifying a plurality of static devices, obtaining location measurements by the plurality of static devices at different times, and determining locations of the plurality of static devices using the location measurements obtained at the different times. The method of determining locations of the plurality of static devices includes determining a group location of the plurality of static devices based on GNSS pseudo range measurements contributed by the one or more static devices, where the group location is near a centroid of the plurality of static devices weighted by the number of GNSS pseudo range measurements contributed by each of the plurality of static devices. The method of determining locations of the plurality of static devices further includes sharing a common time reference among the plurality of static devices.