Portable-Key Location Determiner Using UWB CIR Asymmetry
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Solution Overview
Problem
Existing short-range wireless communication technologies for portable key devices, such as Bluetooth Low Energy (BLE) and ultra-wideband (UWB), face challenges in reliably determining whether the device is on the inside or outside of a barrier, leading to unintended unlocking and potential security breaches.
Innovation Solution
A location determiner with a radio asymmetry device that includes edge wave guides, peripheral wave blockers, and radio wave diffusers to enhance the asymmetry in channel impulse response (CIR) between antennas, allowing accurate determination of the portable key device's location relative to the barrier.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If short-range wireless communication with longer communication range (e.g., BLE, UWB) is used to allow the portable key device to stay in a pocket or handbag, then convenience is improved, but the risk of unintended unlocking increases when a person on the inside walks past or hangs a coat on the lock
Solution Approach 1:
The patent applies asymmetry by providing a radio asymmetry device with asymmetric structure relative to the barrier, including at least one radio wave reflecting element arranged asymmetrically. This creates different channel impulse response (CIR) characteristics for signals arriving from the front side versus the back side, enabling the system to distinguish between intentional access attempts from outside and unintentional triggering from inside, thus resolving the security risk while maintaining convenience
2Reliability
If RFID is used for access control, then the wireless interface is established, but the user must actively take out the portable key device and bring it within centimetres of the lock, which is inconvenient and potentially insecure
Solution Approach 1:
The patent replaces the mechanical proximity requirement of RFID (where the device must be physically brought within centimetres of the lock) with a wireless determination system using UWB communication and CIR analysis. The system automatically determines location based on signal characteristics rather than requiring physical proximity, eliminating the need for active user action to present the device while maintaining security through asymmetric radio wave analysis
3Extent of automation
If the electronic lock unlocks whenever an authorised portable key device is within range, then automatic access control is enabled, but a person on the inside can trigger the unlock procedure unintentionally
Solution Approach 1:
The patent implements feedback by analyzing the channel impulse response (CIR) characteristics of the radio signals and using this information to determine whether the portable key device is on the front side or back side of the barrier. The system continuously monitors signal characteristics and adjusts access control decisions based on the determined location, enabling automatic access control to function reliably without unintended unlocking from the inside
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
Enhances the reliability of determining the device's location, preventing unintended unlocking and improving security by ensuring access control is only granted when the device is outside the barrier.
Implementation Method 1
The radio asymmetry device may comprise an edge wave guide provided by an edge of the metal plate, the edge being closer to the first antenna than the second antenna, whereby the edge wave guide is configured to increase a signal level of the UWB impulse signal at the first antenna more than at the second antenna.
Implementation Method 2
The radio asymmetry device may comprise a first peripheral wave blocker provided in contact with an edge of the metal plate, the edge being closer to the first antenna than the second antenna, whereby the first peripheral wave blocker is configured to increase path length of the UWB impulse signal to the first antenna compared to the path length to the path length to the second antenna.
Implementation Method 3
The RF absorber may be provided such that deflection of an UWB impulse signal from the back side around the metal plate to the first antenna is reduced.
Data Source
Figure 1
Figure 2A~2B
Figure 3A~3B
AI summary
It is provided a location determiner comprising: a first antenna; a radio signal modification device, wherein the radio signal modification device is configured to improve an ability to determine whether the portable key device is located on a back side or on a front side of the location determiner, based on obtaining a channel impulse response, CIR, of an impulse signal transmitted from the portable key device, wherein the location determiner is installable such that the back side is in a space being restricted by selectively unlockable a physical barrier and the front side is opposite the back side.