NFC Start Pattern Detection Using Sub-Matched Filters Against Noise
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
NFC devices face deterioration in distance performance due to exposure to environmental noise signals, particularly difficulty in distinguishing noise signals from start patterns in data frames, leading to reduced reception capabilities.
Innovation Solution
An NFC device with an antenna receiving data frames containing start patterns modulated by a sub-carrier frequency, utilizing analog-to-digital converters to generate input signals and a modem with sub-matched filters to determine start pattern reception by calculating result values that exceed predetermined thresholds, improving noise resistance and reception distance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the antenna is miniaturized to fit electronic devices, then the device size is reduced, but the reception distance performance deteriorates due to increased susceptibility to environmental noise signals
Solution Approach 1:
The patent segments the start pattern detection into multiple sub-patterns (first start pattern, second start pattern, third start pattern) that are processed independently by separate matched filters. This segmentation allows the system to analyze each pattern component individually, improving noise resistance while maintaining miniaturized antenna design.
Solution Approach 2:
The patent introduces an intermediary processing stage between signal reception and final detection, where multiple matched filters process different start pattern variations. This intermediary layer acts as a mediator that enhances signal discrimination capability, allowing reliable detection despite the miniaturized antenna's susceptibility to noise.
2Device complexity
If the NFC device uses simple start pattern detection, then the device complexity is reduced, but the ability to distinguish noise signals from valid start patterns deteriorates
Solution Approach 1:
The detection mechanism is segmented into multiple specialized matched filters, each configured to detect specific start pattern variations. This segmentation enables precise discrimination between valid start patterns and noise signals while maintaining manageable device complexity through modular filter design.
Solution Approach 2:
The patent implements a universal detection framework where multiple matched filters serve different start pattern types (first, second, third start patterns). This multi-functional approach allows a single detection system to handle various pattern variations, improving recognition accuracy without proportionally increasing overall system complexity.
3Measurement precision
If multiple matched filters are used to detect different start patterns, then the start pattern recognition accuracy is improved, but the device complexity increases
Solution Approach 1:
The complex detection task is segmented into multiple independent matched filter operations, each handling a specific start pattern type. This segmentation allows the system to achieve high detection accuracy through specialized processing while managing complexity by dividing the overall function into discrete, manageable filter modules.
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
Enhances the NFC device's reception distance performance by effectively differentiating start patterns from noise signals, thereby stabilizing data frame reception and reducing errors caused by noise interference.
Implementation Method 1
an analog-to-digital converter which samples the first pattern signal at a sampling period to generate a first input signal, and samples the second pattern signal at the sampling period to generate a second input signal
Implementation Method 2
a first sub-matched filter which multiplies a first match signal generated on the basis of the sampling period by the first input signal to calculate a first result value of the first match signal and multiplies the first match signal by the second input signal to calculate a second result value of the first match signal
Data Source
AI summary
An NFC device that receive a data frame with a start pattern including first and second pattern signals, and a data pattern corresponding to the start pattern. The NFC device comprising an analog-to-digital converter which generates first and second input signals based on the first and second pattern signals, respectively, a modem that includes a first sub-matched filter which multiplies a first match signal by the first and second input signals to respectively calculate first and second result values of the first match signal and multiplies a second match signal by the first and second input signals to respectively calculate first and second result values of the second match signal. The first sub-matched filter determines reception of the start pattern when the first and second result values of the first match signal or the first and second result values of the second match signal exceed a predetermined start pattern threshold.