Distance Estimation Using Multi-Scale Transform for Burst Noise Removal

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Solution Overview

Problem

Conventional distance estimation methods in wireless communications struggle with accuracy due to environmental noise, particularly burst noise, which can lead to significant errors in determining the distance between nodes, as they fail to accurately identify and remove noise components, often affecting the validity of signal strength measurements.

Innovation Solution

A method that employs multi-scale transform to project received signal strengths onto multiple scales, allowing for the accurate identification and removal of burst noise components, and utilizes a multi-scale empirical mapping relationship to estimate real-time distances, incorporating both timely and historical signal strength data for precise distance determination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a filter is used to remove burst noise before distance estimation, then the distance estimation process can proceed, but it is easy to remove valid signals and/or impossible to completely remove burst noise, resulting in offset in the distance estimation result

Engineering Contradiction:
Improvedistance estimation reliabilityVSAvoiddistance estimation precision
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent segments the received signal strength sequence into multiple scales using multi-scale transform (e.g., wavelet transform). This decomposition separates the signal into different frequency components and time scales, allowing burst noise to be identified and removed from specific scales while preserving valid signals in other scales. The segmentation enables selective noise removal without affecting the entire signal uniformly.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts burst noise components from the received signal strength sequence by analyzing multi-scale transform results. By identifying abnormal values in specific scales and time positions, the method extracts and removes only the burst noise portions while retaining valid signal components. This extraction approach prevents the loss of valid signals that would occur with traditional filtering.

Inventive Principle:
Principle #2Taking out (Extraction)

2Ease of manufacture

If conventional filtering is applied to remove burst noise, then the processing is simple, but the position of burst noise cannot be accurately determined, leading to incomplete noise removal and offset in results

Engineering Contradiction:
Improveprocessing simplicityVSAvoidnoise position determination precision
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent transforms the one-dimensional signal strength sequence into a multi-dimensional representation through multi-scale transform. This adds time-scale and frequency dimensions, enabling the identification of burst noise not only by amplitude but also by its temporal and spectral characteristics. The additional dimensions provide more information for accurate noise position determination while maintaining computational feasibility.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Ease of operation

If burst noise is not taken into account in distance estimation, then the estimation process is straightforward, but when burst noise occurs, the distance estimation result becomes inaccurate

Engineering Contradiction:
Improveestimation process simplicityVSAvoiddistance estimation precision under noise
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent performs preliminary action by conducting multi-scale transform and burst noise removal before the distance estimation process. This preprocessing step prepares the signal by eliminating burst noise components in advance, ensuring that the subsequent distance estimation uses clean data. The preliminary noise removal prevents accuracy degradation while keeping the main estimation process simple.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces multi-scale transform as an intermediary process between signal reception and distance estimation. This intermediary step transforms the raw signal into a multi-scale representation where burst noise becomes distinguishable from valid signals. The transform acts as a mediator that facilitates noise identification and removal without complicating the final distance calculation.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentUS9903943B2Distance estimation method and device as well as node localization method and apparatus
Publication Date: 2018.02.27 RICOH CO LTD
  • US9903943B2 patent drawing
  • US9903943B2 patent drawing
  • US9903943B2 patent drawing

AI summary

Disclosed is a method of estimating the distance between two nodes. The method includes obtaining an original real-time strength sequence, its elements being strengths of signals between the two nodes at respective time slots of a first time period; conducting multi-scale transform with respect to the original real-time strength sequence so as to acquire plural real-time strength component sequences which are results of the original real-time strength sequence projected onto plural scales; removing at least one burst noise element in each real-time strength component sequence so as to get plural updated real-time strength component sequences; estimating, based on the plural updated real-time strength component sequences and a multi-scale empirical mapping relationship, an empirical real-time distance, the multi-scale empirical mapping relationship being used for expressing correspondence relations between strength components and distance components; and determining, based on at least the empirical real-time distance, a real-time distance between the two nodes.