Indoor Positioning via RSSI Vector Summation
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Solution Overview
Problem
Current indoor positioning systems face challenges in accurately determining location without a direct line of sight to outdoor positioning systems, often requiring costly infrastructure and accurate timing, and are compromised by signal reflections and shadows.
Innovation Solution
An indoor positioning system using beacons that generate broadcast signals with unique identifiers, allowing receivers to determine their location through vector calculations based on signal strength and direction, without the need for network synchronization or accurate timing, enabling accurate and flexible low-cost positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If time-of-flight systems are used for indoor positioning, then positioning accuracy can be achieved, but system cost and complexity increase due to requirements for highly accurate timing infrastructure and synchronized transmitters
Solution Approach 1:
The patent replaces time-of-flight measurement mechanisms with signal strength-based positioning. Instead of measuring the time for signals to propagate between transmitters and receiver, the system uses received signal strength indicators (RSSI) to determine position, thereby eliminating the need for precise timing infrastructure and synchronized clocks while maintaining positioning capability
Solution Approach 2:
The patent employs inexpensive low-power beacons that broadcast unique identifiers periodically rather than using expensive synchronized timing infrastructure. These simple beacons can be deployed easily in indoor environments without requiring complex synchronization systems, reducing overall system cost and complexity
2Measurement precision
If time-of-flight systems are used for indoor positioning, then positioning accuracy can be achieved, but infrastructure cost increases significantly
Solution Approach 1:
The patent uses inexpensive low-power beacons that can be easily deployed in indoor environments. These beacons broadcast unique identifiers and are significantly cheaper than traditional time-of-flight transmitters, allowing for cost-effective indoor positioning without requiring expensive infrastructure investments
Solution Approach 2:
The patent extracts the timing synchronization requirement from the positioning system. By removing the need for synchronized clocks and precise timekeeping infrastructure, the system achieves positioning accuracy using only signal strength measurements from simple beacons, thereby reducing infrastructure cost
3Loss of time
If angle of arrival systems are used for indoor positioning, then positioning can be achieved without time synchronization, but system cost increases due to directional antennas and antenna arrays
Solution Approach 1:
The patent replaces angle-of-arrival measurement systems with signal strength-based positioning. Instead of using directional antennas and antenna arrays to measure signal angles, the system uses simple receivers that measure signal strength (RSSI) from omnidirectional beacons, eliminating the need for complex antenna structures while maintaining positioning capability
4Adaptability or versatility
If signal reflections and shadows are present in the environment, then indoor positioning becomes possible, but positioning accuracy is compromised in time-of-flight systems
Solution Approach 1:
The patent changes the positioning parameter from time-based measurements to signal strength-based measurements. By using received signal strength indicators (RSSI) instead of time-of-flight or angle-of-arrival measurements, the system becomes less sensitive to signal reflections and shadows, as RSSI can still provide positioning information even when direct line-of-sight signals are obstructed
Data Source
AI summary
A non-time of flight or time of arrival position location system for accurate determination of a user's location in an enclosed, indoor, or covered environment can include a number of beacons mounted in an arrangement within the environment. Each of the beacons is mounted in a known location and transmits a broadcast signal containing a unique identifier that identifies the originating beacon. A handheld electronic device including a receiver and a communicably coupled processor can receive broadcast signals from at least some of the number of beacons, iteratively determine a vector quantity corresponding to each of the received signals, and sum the resultant vector quantities to determine an updated position. The iterative process can be repeated until consecutive iterations yield an updated position that falls within a defined threshold.