Dynamic Signal Filter for Irregular Wireless Updates

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Solution Overview

Problem

Existing wireless networking systems face inaccuracies in estimating distance, motion, and location due to signal strength variance and irregular message transmission intervals, leading to noise in signal attenuation through mediums like air or water.

Innovation Solution

A dynamically windowed filter is used to weight and decay signal strength values, reducing noise by considering a dynamic time window and elapsed time between signal samples, allowing for more accurate signal strength estimation and movement tracking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If signal strength measurements are taken at irregular intervals, then the system can adapt to variable transmission conditions, but the measurement precision deteriorates due to noise and variance

Engineering Contradiction:
Improveadaptability to variable transmission conditionsVSAvoidsignal strength measurement precision
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent applies a dynamically windowed filter that adjusts the time window size based on the elapsed time between consecutive signal samples. When samples arrive at irregular intervals, the filter dynamically modifies its parameters to maintain optimal filtering performance, thereby preserving measurement precision while accommodating variable transmission conditions

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The filter changes its operational parameters (time window size, decay factors) based on the elapsed time between samples. By adjusting these parameters dynamically, the system maintains accurate signal strength estimation despite irregular sampling intervals, resolving the contradiction between adaptability and measurement precision

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If a fixed time window is used for filtering, then the system is simple to implement, but it cannot handle irregular update intervals effectively

Engineering Contradiction:
Improvefiltering system complexityVSAvoidability to handle irregular update intervals
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent transforms the fixed time window into a dynamic structure that automatically adjusts based on the elapsed time between consecutive samples. This dynamic adaptation allows the filter to handle irregular update intervals effectively while maintaining relatively simple implementation through straightforward parameter adjustments

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The filter uses feedback from the elapsed time between samples to adjust its time window parameters. This feedback mechanism enables the system to adapt to irregular update intervals without requiring complex external control, maintaining simplicity while improving adaptability

Inventive Principle:
Principle #23Feedback

3Speed

If signal strength values are used directly without filtering, then the response time is fast, but the noise in the signal reduces the reliability of distance and location estimates

Engineering Contradiction:
Improveresponse speedVSAvoidreliability of distance and location estimates
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The dynamically windowed filter provides adaptive noise reduction that maintains responsiveness. By adjusting the time window based on sample intervals, the filter removes noise without introducing excessive delay, thereby maintaining both speed and reliability in distance and location estimation

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The filter changes its processing parameters based on the timing characteristics of incoming samples. This dynamic parameter adjustment allows the system to maintain fast response while effectively filtering noise, improving the reliability of estimates without significant speed penalty

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS8594606B2Smoothing filter for irregular update intervals
Publication Date: 2013.11.26 TRAPEZE NETWORKS INC
  • US8594606B2 patent drawing
  • US8594606B2 patent drawing
  • US8594606B2 patent drawing

AI summary

A technique for determining a received signal strength from multiple messages filters noise from the received signal to provide an accurate signal strength value. Advantageously, the more accurate output signal strength value can be used to identify movement of a station as well as estimate locations and direction of movement.