UWB Ranging Device Peak Validation for Interference

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Solution Overview

Problem

Existing UWB ranging technologies face challenges in accurately determining the time of arrival of a signal due to destructive interference from reflected signals, leading to erroneous distance estimates that can compromise security applications.

Innovation Solution

The method involves determining a channel impulse response based on the received signal, identifying a candidate time value as the earliest point of a peak in the impulse response, and applying conditions to verify if the peak is not caused by destructive interference. If conditions are not met, the candidate time value is set as the time of arrival.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the earliest peak in the channel impulse response is used to determine time of arrival, then the ranging speed is improved, but the measurement precision deteriorates due to destructive interference from reflected signals

Engineering Contradiction:
Improveranging speedVSAvoidtime of arrival accuracy
Core Design Contradiction:
SpeedVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by performing a validity check on the earliest peak before using it for time of arrival determination. The method预先 (in advance) verifies whether the peak at the earliest time t1 satisfies the amplitude conditions (A(t1+Δt) < A(t1) + δA and A(t1-Δt) > A(t1) - δA) to detect potential destructive interference. This preliminary validation prevents erroneous TOA selection while maintaining the speed advantage of using the earliest peak when it is valid.

Inventive Principle:
Principle #10Preliminary action

2Device complexity

If simple peak detection is used to determine time of arrival, then the device complexity is reduced, but the reliability deteriorates due to erroneous distance estimates in environments with strong reflections

Engineering Contradiction:
Improveprocessing complexityVSAvoidranging reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent implements feedback by using the amplitude information from time points around the peak (t1-Δt and t1+Δt) to validate whether the peak at t1 is genuine or caused by destructive interference. The amplitude differences are compared against threshold values (δA1 and δA2) to provide feedback on the validity of the peak selection. This feedback mechanism ensures reliable ranging without requiring complex additional hardware.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4148462B1UWB ranging method, device, and system
Publication Date: 2025.05.14 NXP BV
  • EP4148462B1 patent drawingFigure 1~2
  • EP4148462B1 patent drawingFigure 3~4
  • EP4148462B1 patent drawingFigure 5~6

AI summary

There is described a method of determining a time of arrival of a signal at a UWB ranging device comprising a first antenna, the signal being transmitted by another UWB ranging device, the method comprising: determining a first channel impulse response based on at least a part of the signal received at the first antenna; determining a first time value as an earliest point in time at which the amplitude of the first channel impulse response exhibits a peak value; setting a candidate time value to the first time value; determining a first upper value as the amplitude of the first channel impulse response at a time value corresponding to the candidate time value plus a predetermined upper time value; determining a second upper value as the peak value plus a predetermined upper amplitude value; determining a first lower value as the amplitude of the first channel impulse response at a time value corresponding to the candidate time value minus a predetermined lower time value; determining a second lower value as the peak value minus a predetermined lower amplitude value; determining, as a first condition, whether the first upper value is larger than the second upper value; determining, as a second condition, whether the first lower value is smaller than the second lower value; and if at least one of the first condition and the second condition is not fulfilled, setting the time of arrival to the candidate time value. Furthermore, a UWB ranging device and a UWB system are described.