Channel Impulse Response Estimation Using Inverse Matrix

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing methods for estimating the impulse response of a channel, particularly in acoustic monitoring, face challenges with unwanted echoes and structured noise, limiting temporal resolution and accuracy when the environment or channel changes over time.

Innovation Solution

Applying a calculated inverse matrix, such as a pseudo-inverse matrix, to the received signal to estimate the channel response without requiring orthogonal codes or the 'send-receive-wait' technique, allowing for continuous and frequent monitoring of channel changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If impulses are transmitted more frequently to improve temporal resolution, then temporal resolution is improved, but structured noise from lingering echoes distorts the estimates

Engineering Contradiction:

Improvetemporal resolutionVSAvoidestimate accuracy

Core Design Contradiction:

Loss of timeVSMeasurement precision

Solution Approach 1:

A filter is introduced as an intermediary component between the transmitted impulse and the received signal processing. This filter processes the received signal to remove the influence of structured noise from lingering echoes, allowing frequent impulse transmissions to maintain both high temporal resolution and accurate estimates.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If the 'send-receive-wait' method is used to avoid structured noise, then estimate accuracy is improved, but temporal resolution is severely limited

Engineering Contradiction:

Improveestimate accuracyVSAvoidtemporal resolution

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The system enables continuous and frequent impulse transmissions without requiring long waiting periods between sends. The filter continuously processes incoming signals to eliminate structured noise, allowing the measurement process to continue uninterrupted and achieve both high accuracy and temporal resolution.

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

The filter acts as a mediator that allows frequent transmissions by removing the harmful structured noise component, eliminating the need for the send-receive-wait cycle while maintaining estimate accuracy.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Measurement precision

If orthogonal codes are used to reduce interference, then measurement precision is improved, but device complexity increases

Engineering Contradiction:

Improveestimate accuracyVSAvoidcode requirements

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

Instead of using complex orthogonal codes, the system employs simple, non-orthogonal impulses that are transmitted repeatedly. The filter processes these simple signals to eliminate structured noise, achieving accurate estimates without requiring complex coding schemes.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Data Source

PatentUS7768876B2Channel impulse response estimation

Publication Date: 2010.08.03 ELLIPTIC LAB AS

AI summary

A method of estimating the impulse response of a channel is disclosed. The method includes transmitting an impulse signal to the channel, detecting a received signal from the channel, and calculating an estimate of the impulse response of the channel by applying a calculated inverse matrix of the impulse signal to the received signal.