Phase Position Modulation for RFID Signal Reliability

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Solution Overview

Problem

RFID systems face challenges with reduced signal strength due to regulatory limits, leading to increased susceptibility to noise and reduced reliability, especially in applications requiring high-speed data transmission, as existing methods like Phase Jitter Modulation and Modified Frequency Modulation are either too slow or susceptible to noise.

Innovation Solution

The use of Phase Position Modulation (PHPM) and Amplitude Position Modulation (AMPM) techniques, which encode data through amplitude or phase changes relative to time intervals, allowing for increased signal strength within spectral mask limits while maintaining reliability and reducing high-frequency spectral content.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If Phase Jitter Modulation is used to achieve high data rates, then data transmission speed is improved, but signal strength is reduced and susceptibility to noise increases

Engineering Contradiction:
Improvedata transmission speedVSAvoidsignal transmission reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent changes the modulation parameter from phase jitter (PJM) to phase position modulation (PPM), where data is encoded in the position of phase transitions rather than the amount of jitter. This allows for stronger signal levels while maintaining high data rates, resolving the contradiction between speed and reliability.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If signal strength is increased to improve reliability, then signal-to-noise ratio is improved, but spectral mask limits are exceeded

Engineering Contradiction:
Improvesignal transmission reliabilityVSAvoidspectral mask compliance
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent transitions from PJM to PPM modulation, which changes the spectral characteristics of the signal. PPM concentrates signal energy more efficiently within the allowed spectral mask while maintaining reliability, allowing higher effective signal strength without exceeding regulatory limits.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If conventional modulation methods are used to meet spectral limits, then spectral compliance is achieved, but data transmission rate is reduced

Engineering Contradiction:
Improvespectral mask complianceVSAvoiddata transmission rate
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent employs phase position modulation with optimized time interval encoding, which achieves better spectral efficiency than conventional methods. This allows high data rates to be maintained while staying within spectral mask compliance, unlike traditional approaches that must sacrifice speed for compliance.

Inventive Principle:
Principle #35Parameter changes

4Productivity

If more signal power is allocated to modulated sidebands to increase data rate, then transmission speed is improved, but power in central carrier is reduced

Engineering Contradiction:
Improvedata transmission rateVSAvoidcentral carrier power
Core Design Contradiction:
ProductivityVSPower

Solution Approach 1:

The patent uses phase position modulation where data is encoded in the timing position of phase transitions rather than in the amplitude or frequency of sidebands. This approach maintains strong central carrier power while achieving high data rates through precise timing information, reversing the traditional trade-off.

Inventive Principle:
Principle #35Parameter changes

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

PHPM and AMPM enhance signal reliability, increase data rates, and reduce spectral occupancy, resulting in improved signal-to-noise ratios and more efficient receiver designs with lower power consumption and smaller chip areas, enabling robust high-speed RF signal transmission.

Implementation Method 1

Phase Position Modulation (PHPM) and Amplitude Position Modulation (AMPM) techniques, which encode data through amplitude or phase changes relative to time intervals

Methodology Applied
Scientific EffectPhase modulation: Phase Modulation

Implementation Method 2

Phase Position Modulation (PHPM) and Amplitude Position Modulation (AMPM) techniques, which encode data through amplitude or phase changes relative to time intervals

Methodology Applied
Scientific EffectAmplitude modulation: Phase Modulation

Data Source

PatentEP2108225B2Communication method and device
Publication Date: 2022.02.09 SATO HLDG CORP
  • EP2108225B2 patent drawingFigure 1
  • EP2108225B2 patent drawingFigure 2
  • EP2108225B2 patent drawingFigure 3

AI summary

The present invention relates to the field of communication and transmission of signals. In particular, the present invention relates to a new communication and/or modulation method. The present invention also relates to improving channel occupancy. The present specification discloses the adoption of phase transitions/changes in a manner that indicates a code by virtue of their position (timing) in the communication. This is referred to as Phase Position Modulation.