Radio Wave Timepiece Signal Classification via Correlation Analysis

Solution Overview

Problem

Conventional radio wave timepieces face challenges in quickly and accurately obtaining time information from standard time radio waves due to noise interference, requiring multiple restarts of the processing circuit and prolonging the time to obtain time information.

Innovation Solution

A time information obtaining apparatus that compares input waveform data with predicted waveform data to simultaneously determine the class of the standard time radio wave and identify the second pulse position, using correlation values calculated from covariance to enhance processing efficiency and accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional processing circuits perform sequential processing (second synchronization, minute synchronization, code capturing, consistency judgment), then the processing can be completed systematically, but the processing time becomes remarkably long due to multiple restarts caused by noise

Engineering Contradiction:

Improveprocessing completionVSAvoidtime to obtain time information

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent performs second synchronization processing in advance by detecting the second pulse position before formal time information processing. The correlation value calculation between input waveform data and predicted waveform data identifies the second pulse position preliminarily, allowing the main processing to start without delay even if noise causes restarts. This preliminary detection ensures the processing can resume from the correct position.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses correlation values as feedback to continuously monitor and identify the second pulse position. By calculating correlation values between input waveform data and predicted waveform data, the system can detect deviations caused by noise and adjust the processing to maintain accurate time information extraction, preventing complete restarts.

Inventive Principle:

Principle #23Feedback

2Measurement precision

If the processing circuit restarts multiple times due to noise interference, then the processing can potentially achieve accurate time information, but the overall processing efficiency deteriorates significantly

Engineering Contradiction:

Improvetime information accuracyVSAvoidprocessing efficiency

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The patent performs second synchronization processing in advance by detecting the second pulse position before formal time information processing. The correlation value calculation between input waveform data and predicted waveform data identifies the second pulse position preliminarily, allowing the main processing to start without delay even if noise causes restarts. This preliminary detection ensures the processing can resume from the correct position.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If the processing circuit performs comprehensive processing steps, then the time information can be obtained accurately, but the complexity of the processing increases

Engineering Contradiction:

Improvetime information accuracyVSAvoidprocessing circuit complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent performs second synchronization processing in advance by detecting the second pulse position before formal time information processing. The correlation value calculation between input waveform data and predicted waveform data identifies the second pulse position preliminarily, allowing the main processing to start without delay even if noise causes restarts. This preliminary detection ensures the processing can resume from the correct position.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentEP2219087B1Time information obtaining apparatus and radio wave timepiece

Publication Date: 2013.01.09 CASIO COMPUTER CO LTD

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Figure 5A~5C

AI summary

A time information obtaining apparatus, comprises: a receiving section (16) for receiving a standard time radio wave; an input waveform data generating section (22, 24) for sampling a signal including a time code output from the receiving section (16) at a predetermined sampling period to obtain sampling points every one unit time length corresponding to one code constituting the time code, each of the sampling points being a value expressed by a plurality of bits, and generating input waveform data having one or more unit time lengths based on data having at least one of the unit time lengths each including the obtained sampling points; a predicted waveform data generating section (23) for generating a plurality of pieces of predicted waveform data, each sampling point of which being a value expressed by a plurality of bits, the predicted waveform data having a same time length as that of the input waveform data, the predicted waveform data having one or more unit time lengths representing each of classes of standard time radio waves with respect to each class of the standard time radio wave; a correlation value calculating section (25) for calculating correlation values between the input waveform data and the plurality of pieces of predicted waveform data of each of the classes; a correlation value comparing section (26) for comparing the correlation values calculated by the correlation value calculating section (25) to one another to calculate an optimum value of the correlation values of each of the classes; and a judging section (11) for judging the class of the standard time wave based on the optimum value of each of the classes.