UWB Ranging Jitter Removal via Low-Pass Filtering

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Solution Overview

Problem

Existing UWB ranging methods in smart home scenarios face challenges with jitter in time of flight (ToF) measurements, leading to inaccurate ranging results. This is exacerbated by the need for additional sensors and increased processing complexity, particularly in IoT devices.

Innovation Solution

A UWB ranging method that filters the acquired time of flight using a low-pass filter, removing jitter and ensuring accurate ranging results without the need for additional sensors. This method determines the state transition equation of the low-pass filter based on sampling frequency and cutoff frequency, and iteratively processes the ToF values to obtain filtered results.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If additional sensors and complex processing methods (e.g., Kalman filters) are used to improve ranging accuracy, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improveranging accuracyVSAvoidprocessing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts and removes the harmful jitter component from ToF measurements using a low-pass filter, separating the useful ranging signal from the noisy measurement. This approach achieves accurate ranging without requiring additional sensors or complex processing algorithms like Kalman filters, thereby reducing device complexity while maintaining measurement precision.

Inventive Principle:
Principle #2Taking out (Extraction)

2Measurement precision

If additional sensors are added to improve ranging accuracy, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improveranging accuracyVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system uses its existing UWB communication infrastructure to perform ranging measurements and applies a low-pass filter to remove jitter from the measurements. The solution serves itself by utilizing already-present hardware and software resources rather than requiring additional sensors, thereby achieving improved ranging accuracy without increasing device complexity.

Inventive Principle:
Principle #25Self-service

3Productivity

If ToF measurements are used for UWB ranging, then ranging capability is achieved, but jitter in measurements reduces reliability

Engineering Contradiction:
Improveranging capabilityVSAvoidranging reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent converts the harmful effect of jitter in ToF measurements into a beneficial filtering operation. By applying a low-pass filter with an appropriately chosen cutoff frequency, the system removes the high-frequency jitter noise from the measurements while preserving the useful ranging information, thereby converting measurement instability into reliable ranging data.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Data Source

PatentEP4174519B1UWB ranging method and UWB ranging apparatus
Publication Date: 2025.04.09 BEIJING XIAOMI MOBILE SOFTWARE CO LTD
  • EP4174519B1 patent drawingFigure 1~2
  • EP4174519B1 patent drawingFigure 3~4
  • EP4174519B1 patent drawingFigure 5

AI summary

An Ultra Wide Band (UWB) ranging method, a UWB ranging apparatus, and a non-transitory storage medium thereof are provided. The UWB ranging method includes: filtering (S11), in response to determining a first time of flight for UWB ranging, the first time of flight based on a low-pass filter to obtain a filtered first time of flight; and performing (S12) the UWB ranging based on the filtered first time of flight.