Channel Propagation Emulator Multiplicative Doppler Shift

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Solution Overview

Problem

Conventional channel emulators inaccurately model Doppler shift using additive frequency shifts, leading to errors when dealing with relativistic effects and wideband signals, making it difficult to test wireless communication equipment for high-speed environments without expensive on-site testing.

Innovation Solution

A channel propagation emulator that separates the propagation model from the emulator hardware, allowing for accurate multiplicative frequency Doppler shift emulation, enabling flexible and scalable wireless channel emulation capable of modeling relativistic effects and path loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If additive frequency shift is used to model Doppler shift, then the emulator structure is simple, but the modeling accuracy deteriorates for relativistic effects and wideband signals

Engineering Contradiction:

Improveemulator structureVSAvoidDoppler shift modeling accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent transforms the Doppler shift model from an additive frequency approach to a multiplicative time-scaling approach. By changing the fundamental parameter representation from frequency-domain addition to time-domain multiplication, the system achieves accurate relativistic Doppler modeling while maintaining implementation simplicity through software-based time-stretch processing.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces traditional hardware-based frequency shifting mechanisms with software-based time-scaling algorithms. Instead of using mechanical or electronic frequency converters, the system uses digital signal processing to achieve Doppler effects through time-domain operations, thereby improving accuracy without adding hardware complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Ease of manufacture

If conventional channel emulators are used, then testing can be conducted without expensive on-site deployment, but the emulation accuracy for high-speed environments is insufficient

Engineering Contradiction:

Improvetesting costVSAvoidequipment performance validation

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent creates an accurate virtual copy of relativistic wireless channels through software-based emulation. By modeling the time-scaling and frequency-shift effects of relativistic Doppler in a controlled software environment, the system enables reliable equipment testing without requiring expensive deployment in actual high-speed scenarios, thereby maintaining both cost-effectiveness and validation reliability.

Inventive Principle:

Principle #26Copying

3Device complexity

If the propagation model is integrated with emulator hardware, then the system is simpler, but the flexibility and scalability are reduced

Engineering Contradiction:

Improvesystem integrationVSAvoidemulation scenario flexibility

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent separates the propagation model from the hardware platform, creating an independent software module that can be applied to different hardware configurations. This segmentation allows the same accurate relativistic Doppler model to be deployed across various emulator hardware types, thereby maintaining system simplicity while dramatically improving flexibility and scalability for different emulation scenarios.

Inventive Principle:

Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables accurate testing of wireless communication equipment for high-speed environments by accurately modeling Doppler shift and path loss, reducing testing costs and ensuring equipment performance before deployment.

Implementation Method 1

modifying the input RF data according to channel effects including signal delay, propagation loss and Doppler shift effect to generate an RF output

Methodology Applied

Scientific EffectDoppler shift effect: Doppler Effect

Data Source

PatentUS10498470B1Relativistic wireless channel emulator

Publication Date: 2019.12.03 JOHNS HOPKINS UNIVERSITY

AI summary

A channel propagation emulator includes a radio peripheral configured to receive input radio frequency (RF) data and modify the input RF data according to channel effects including signal delay, propagation loss and Doppler shift effect to generate an RF output, and a host device operably coupled to the radio peripheral. The RF output represents a modification of the input RF data based on a propagation model. The host device operably coupled to an external controller and is configured to define emulation parameters based on the propagation model. The propagation model is selected at the external controller. The external controller is configured to provide instructions for implementing the Doppler shift effect to include spreading that is multiplicative in frequency.