发明名称 |
Frequency deviation detecting apparatus and frequency deviation detecting method |
摘要 |
A frequency deviation detecting apparatus for detecting frequency deviation of a dual tone multiple frequency (DTMF) signal includes frequency deviation analyzers for analyzing a received signal for frequency components proximate fixed frequencies in analytical blocks, each analytical block having a length that ensures the precision required for detecting the frequency deviation. Each of the analytical blocks of the deviation analyzers partially overlays an adjacent block so that analysis by at least one analytical block is ensured within a minimum duration of a DTMF signal.
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申请公布号 |
US6731745(B1) |
申请公布日期 |
2004.05.04 |
申请号 |
US19990422062 |
申请日期 |
1999.10.21 |
申请人 |
MITSUBISHI DENKI KABUSHIKI KAISHA |
发明人 |
GOTO KOJI |
分类号 |
G01R23/10;G01R23/15;G01R23/16;H04L27/26;H04L27/30;H04Q1/45;(IPC1-7):H04M3/00;H04M5/00 |
主分类号 |
G01R23/10 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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