Backscatter Tag CRC Preservation Sequence for Commodity Device Error Detection

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Solution Overview

Problem

Existing backscatter communication systems require specialized hardware and are not compatible with commodity devices, and they lack a method to preserve the frame check sequence (FCS) for error detection in backscattered frames.

Innovation Solution

A backscattering tag that receives a transmitted signal, determines a CRC preservation sequence based on its own data sequence and the given CRC algorithm, and backscatters the signal to include a CRC preservation sequence in the backscattered frame, ensuring the same FCS can be used for error detection in both transmitted and backscattered frames.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If backscatter communication systems use specialized hardware to generate excitation RF signals and decode backscattered signals, then communication reliability is improved, but device complexity and cost increase

Engineering Contradiction:

Improvecommunication reliabilityVSAvoidhardware complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The backscatter tag uses the existing RF signals from commodity devices to communicate without requiring specialized excitation signal generators. The tag reflects modulates the incoming signals, making the system self-sufficient and eliminating the need for complex dedicated hardware while maintaining communication reliability

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The system enables commodity devices with standard RF interfaces to function as backscatter communicators. By making the protocol compatible with general-purpose devices rather than requiring specialized hardware, the invention achieves universal applicability across different device types while maintaining reliable communication

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Loss of information

If the backscattering tag modifies the data sequence to include tag data, then information completeness is improved, but frame check sequence validity deteriorates

Engineering Contradiction:

Improveinformation completenessVSAvoidFCS validity

Core Design Contradiction:

Loss of informationVSReliability

Solution Approach 1:

The invention pre-calculates a CRC preservation sequence based on the tag's data before backscatter transmission. This sequence is designed in advance to compensate for the CRC changes that will occur when tag data is inserted into the reflected frame, ensuring the FCS remains valid after modification

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The CRC preservation sequence acts as an intermediary element that bridges the gap between the modified data sequence (with tag data) and the original FCS. By inserting this carefully calculated sequence, the system maintains CRC validity without requiring recalculation of the entire FCS, thus preserving information completeness while maintaining reliability

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If backscatter communication uses proprietary full duplex hardware add-on, then communication capability is improved, but adaptability to commodity devices deteriorates

Engineering Contradiction:

Improvedevice compatibilityVSAvoidhardware requirement

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The invention replaces expensive, complex proprietary hardware add-ons with simple backscatter tags that can be implemented on commodity devices. By using reflective modulation on existing RF interfaces rather than dedicated full-duplex hardware, the system achieves wide adaptability across smartphones, tablets, and standard Wi-Fi devices without requiring specialized components

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

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 backscatter communication using commodity devices and maintains the FCS for error detection in both the original and backscattered frames, making the system agnostic to transmitters and receivers and compatible with various communication infrastructures.

Implementation Method 1

backscatter the transmitted signal to form a backscattered signal including a backscattered data frame

Methodology Applied

Scientific EffectBackscatter: Scattering

Data Source

PatentEP4576626A1Method and system for preserving a frame check sequence during backscatter communication

Publication Date: 2025.06.25 HAILA TECHNOLOGIES INC

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AI summary

A method for preserving a frame check sequence (FCS) of a data frame during backscatter communication is provided. The method comprises: receiving a transmitted signal including a transmitted data frame, wherein the transmitted data frame includes a first data sequence and the FCS; determining a cyclic redundancy check (CRC) preservation sequence based on a backscattering tag data sequence, a bit-length of the backscattering tag data sequence, and a given CRC algorithm; and backscattering the transmitted signal to form a backscattered signal including a backscattered data frame, wherein the backscattered data frame includes a second data sequence and the FCS. The second data sequence includes a transmitted data sequence, an encoded tag data sequence and the CRC preservation sequence. The CRC preservation sequence preserves the FCS of the transmitted data frame in the backscattered data frame. The FCS is usable to detect communication errors in the backscattered data frame.