Off-Air Access Units for Indoor GPS Localization
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Solution Overview
Problem
Current indoor positioning systems (IPS) face challenges in providing accurate location services indoors due to signal attenuation from building structures, lacking a standard for widespread deployment and requiring complex, expensive infrastructure.
Innovation Solution
A Distributed Antenna System (DAS) utilizing Off-Air Access Units (OAAUs) that receive and route GPS satellite signals optically to Digital Remote Units (DRUs), with an algorithm to delay signals for indoor localization, enabling accurate positioning using existing GPS infrastructure and standard handsets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If GPS satellite signals are used for indoor positioning, then positioning accuracy is improved, but signal strength is attenuated by building structures
Solution Approach 1:
The patent introduces Off-Air Access Units (OAAUs) as intermediary devices that receive GPS satellite signals outdoors where signal strength is sufficient, then relay these signals through building structures to indoor locations via wired connections. This mediator approach allows GPS signals to be available indoors without requiring direct satellite visibility, resolving the contradiction between maintaining positioning accuracy and overcoming signal attenuation.
2Measurement precision
If dedicated indoor positioning infrastructure is deployed, then indoor localization capability is improved, but system complexity and deployment cost increase
Solution Approach 1:
The patent makes existing DAS infrastructure multi-functional by enabling Off-Air Access Units to perform both their traditional wireless access function and GPS signal relay function. By utilizing the existing wired distribution network for GPS signal delivery, the system avoids creating separate dedicated positioning infrastructure, thereby reducing overall system complexity while maintaining indoor localization capability.
3Area of stationary object
If GPS signals are relayed to multiple indoor locations, then coverage area is improved, but signal synchronization becomes more difficult
Solution Approach 1:
The patent replaces wireless signal transmission with wired signal delivery through the DAS network to provide GPS signals to multiple indoor locations. The wired connection provides stable, controlled signal paths that are less susceptible to interference and synchronization issues compared to wireless relay, enabling accurate time-stamped signal delivery across extended coverage areas while maintaining signal synchronization precision.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enhances indoor localization accuracy by utilizing existing GPS infrastructure, providing a cost-effective and efficient means to triangulate user positions indoors, critical for emergency services, and improves the deployment of indoor positioning systems.
Implementation Method 1
route signals optically to one or more DAUs
Data Source
AI summary
A system for indoor localization using satellite navigation signals in a Distributed Antenna System includes a plurality of Off-Air Access Units (OAAUs). Each of the plurality of OAAUs is operable to receive an individual satellite navigation signal from at least one of a plurality of satellites and operable to route signals optically to one or more DAUs. The system also includes a plurality of remote DRUs located at a remote location. The plurality of remote DRUs are operable to receive signals from a plurality of local DAUs. The system further includes an algorithm to delay each individual satellite navigation signal for providing indoor localization at each of the plurality of DRUs and a GPS receiver at the remote location used in a feedback loop with the DRU to control the delays.