Indoor RF Phase Shift Location Tracking
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Solution Overview
Problem
Current location-determination technologies, such as GPS and cellular networks, are inadequate for accurately tracking mobile devices within indoor environments.
Innovation Solution
A system comprising multiple transmitters positioned at known locations, emitting RF signals on a common carrier frequency with repeating timeslots, allowing a mobile device to receive and differentiate these signals, calculate relative phase shifts, and determine its location based on the known transmitter locations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If GPS and cellular network technologies are used for location determination, then location tracking can be provided, but accurate determination of mobile device location in indoor environments cannot be achieved
Solution Approach 1:
The system divides the indoor environment into multiple zones with transmitters positioned at known locations throughout the space. Each transmitter independently emits RF signals, and the mobile device segments the received signals by identifying individual transmitter sources through timeslot discrimination, enabling precise location calculation within the segmented indoor area.
Solution Approach 2:
The patent introduces RF transmitters and a location determination system as intermediaries between the mobile device and the indoor environment. These transmitters emit signals that bounce off or pass through the indoor space, providing reference points that enable accurate location tracking without relying on outdoor-based GPS or cellular networks.
2Measurement precision
If multiple transmitters emit RF signals on a common carrier frequency simultaneously, then location determination can be achieved, but signal differentiation between transmitters becomes difficult
Solution Approach 1:
Each transmitter emits RF signals in periodic timeslots rather than continuously. The signals are modulated with unique periodic patterns that allow the mobile device to distinguish between different transmitters by detecting the timing and pattern of received signals, even though they share the same carrier frequency.
Solution Approach 2:
The system pre-assigns specific timeslots to each transmitter and embeds transmitter identification information in the signal structure before transmission. This preliminary organization of signal transmission allows the mobile device to efficiently differentiate between transmitters without complex real-time signal separation.
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
Enables accurate location determination and tracking of mobile devices indoors, facilitating the provision of location-based services by accurately pinpointing the device's position within indoor environments.
Implementation Method 1
calculating a relative phase shift of each respective RF signal, and calculating the location of the mobile device based on the determined relative phase shifts and the known locations of the three or more transmitters
Data Source
AI summary
Systems, devices, features, and/or methods for determining a location of a mobile device are disclosed. A method may include (a) receiving, into a mobile device, a common RF signal on a common carrier frequency, wherein the common RF signal includes a respective RF signal output by each of three or more transmitters on a common time basis in a round-robin manner, and wherein each of the three or more transmitters is positioned at a known location, (b) capturing data representing the common RF signal, (c) based on the captured data, discriminating between each respective RF signal that forms the received common RF signal, (d) determining a relative phase shift of each respective RF signal, and (e) determining the location of the mobile device based on the determined relative phase shifts and the known locations of the three or more transmitters.