Backscatter Devices for Single Sideband Wireless Communication

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Solution Overview

Problem

Current wireless communication technologies, such as Wi-Fi, face challenges in power efficiency for IoT and ubiquitous sensing scenarios due to high power consumption in analog RF components, which limits the implementation of low-power devices like sensors and mobile devices.

Innovation Solution

The development of backscatter devices that synthesize standard-compliant wireless transmissions, such as Wi-Fi and ZigBee, using a helper device to provide a carrier signal, allowing backscatter devices to operate with significantly lower power consumption by eliminating the need for power-hungry RF components and enabling communication with standard compliant devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If Wi-Fi transmissions are used for wireless communication, then communication capability is achieved, but power consumption increases to hundreds of milliwatts

Engineering Contradiction:
Improvepower consumptionVSAvoidcommunication capability
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent introduces a helper device as an intermediary that transmits carrier signals to the backscatter device. The helper device performs the power-intensive RF signal generation, while the backscatter device only modulates and reflects these signals, thereby separating the high-power transmission function from the low-power communication function and enabling ultra-low power operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The backscatter device creates a copy of the carrier signal by modulating and reflecting the helper device's transmission. Instead of generating original high-power RF signals, the device copies and modifies the carrier wave to encode data, dramatically reducing power consumption while maintaining communication capability.

Inventive Principle:
Principle #26Copying

2Use of energy by moving object

If backscatter techniques are used to create additional data streams, then power consumption is reduced, but data rates become limited at close distances

Engineering Contradiction:
Improvepower consumptionVSAvoiddata rate
Core Design Contradiction:
Use of energy by moving objectVSProductivity

Solution Approach 1:

The patent employs single sideband modulation to change the spectral parameters of the backscattered signal. By suppressing the carrier and one sideband, the technique concentrates power in the remaining sideband, improving signal-to-noise ratio and enabling higher data rates at close distances while maintaining ultra-low power operation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system dynamically adjusts modulation schemes and coding rates based on channel conditions and distance. This allows the backscatter device to optimize data rates for close-proximity communications while maintaining compatibility with standard Wi-Fi receivers, resolving the contradiction between low power consumption and adequate data throughput.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If standard Wi-Fi devices are used for communication, then compatibility is maintained, but power consumption remains high due to RF components

Engineering Contradiction:
ImprovecompatibilityVSAvoidpower consumption
Core Design Contradiction:
Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The patent extracts the high-power RF signal generation function from the backscatter device and places it in the helper device. The backscatter device retains only the essential modulation and reflection functions, eliminating power-hungry RF components while maintaining compatibility with standard Wi-Fi receivers through the use of conventional carrier waves and modulation schemes.

Inventive Principle:
Principle #2Taking out (Extraction)

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

This approach drastically reduces the power consumption and size of sensors, improving battery life and cost, while enabling communication with billions of existing Wi-Fi devices, facilitating the integration of IoT and ubiquitous sensing.

Implementation Method 1

Backscattering techniques have been described that create an additional narrowband data stream to ride on top of existing Wi-Fi signals

Methodology Applied
Scientific EffectBackscatter: Scattering

Implementation Method 2

modulate and reflect the carrier signal to generate backscattered signals at a different frequency

Methodology Applied
Scientific EffectFrequency shifting: Doppler Effect

Data Source

PatentEP3408681B1Backscatter devices including examples of single sideband operation
Publication Date: 2024.01.24 UNIV OF WASHINGTON
  • EP3408681B1 patent drawingFigure 1~2
  • EP3408681B1 patent drawingFigure 3
  • EP3408681B1 patent drawingFigure 4~5

AI summary

Examples described herein include devices and systems utilizing backscatter communication to generate transmissions in accordance with wireless communication protocols. Examples are described including single sideband operation, generation of a carrier wave using Bluetooth, downlink communication to a backscatter device, and combinations thereof.