Virtual Access Points for Wireless Location Accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Real-time location systems (RTLS) face challenges in reducing costs and increasing positional accuracy, as they require multiple access points (APs) for accurate location determination, which increases deployment and wiring costs, and existing solutions often rely on high-cost APs or simpler devices that lack data connectivity functions.
Innovation Solution
The method and system generate a plurality of received signal strengths by distributing access points with multiple antennas, using a W transmit matrix for beamforming to create unique spatial amplitude and phase patterns, allowing a single antenna station to estimate its location by collecting RSSI values from multiple APs, and treating each physical AP as multiple virtual APs to enhance accuracy without increasing hardware costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple physical access points are deployed to improve location accuracy, then positional precision increases, but system cost and deployment complexity increase
Solution Approach 1:
The patent segments a single physical access point into multiple virtual access points by applying different beamforming weight sets to create distinct spatial radiation patterns. Each virtual AP appears as a separate signal source to the wireless device, enabling the system to achieve the location accuracy benefits of multiple APs while using only one physical AP, thus reducing deployment complexity and cost.
Solution Approach 2:
The patent creates virtual copies of the physical access point by generating multiple beamformed signal patterns from a single AP. These virtual APs are mathematical constructs that simulate the presence of multiple physical APs, allowing the system to achieve multi-AP location accuracy without the physical infrastructure costs and complexity.
2Measurement precision
If multiple physical access points are deployed to improve location accuracy, then positional precision increases, but deployment cost increases
Solution Approach 1:
The patent enables a single physical access point to perform the functions of multiple APs by dynamically switching between different beamforming weight sets. This multi-functionality allows one AP to create multiple virtual signal sources, achieving the location determination capabilities of multiple physical APs without the associated hardware costs and deployment expenses.
Solution Approach 2:
The patent changes the beamforming parameters (weight sets) of the single physical AP to create distinct radiation patterns that simulate multiple APs. By varying these parameters over time or across different spatial directions, the system achieves the effect of multiple physical APs with only one physical device, reducing the quantity of hardware required.
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 approach reduces the number of required wireless devices while maintaining or improving location accuracy, allowing for higher precision with fewer physical APs or lower-cost APs, thereby lowering system costs and deployment complexity.
Implementation Method 1
Each AP has two or more antennas with phasing and amplitude of a transmit signal modified by a W transmit matrix prior to transmission, such that each AP is capable of using the W transmit matrix to perform either beam steering or provide a phase and amplitude radiation pattern from each AP
Implementation Method 2
The individual APs operate asynchronously to each other, or transmit a beacon frame at different timeslots to prevent collisions with the other AP beacon frames
Data Source
AI summary
The present invention relates to a method and system of locating a wireless device using received signal strengths. The method comprising: determining a plurality of multiple sets of transmit beamforming weights corresponding to a plurality of access points (APs) associated with a plurality of time slots; transmitting a signal using said each of said plurality of multiple sets of transmit beamforming weights associated with said plurality of time slots by said each access point (AP) of said plurality of access points (APs); and generating a plurality of received signal strengths corresponding to said plurality of time slots associated with said each of said plurality of multiple sets of transmit beamforming weights by said each access point (AP) of said plurality of access points (APs) at any location.