发明授权
- 专利标题: LPC-based DTMF receiver for secondary signalling
- 专利标题(中): 基于LPC的DTMF接收机用于二次信令
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申请号: US201154申请日: 1988-06-02
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公开(公告)号: US4853958A公开(公告)日: 1989-08-01
- 发明人: Rafi Rabipour , Michael G. Beyrouti , Paul Mermelstein
- 申请人: Rafi Rabipour , Michael G. Beyrouti , Paul Mermelstein
- 申请人地址: CAX Montreal
- 专利权人: Northern Telecom Limited
- 当前专利权人: Northern Telecom Limited
- 当前专利权人地址: CAX Montreal
- 主分类号: H04Q1/457
- IPC分类号: H04Q1/457
摘要:
A dual tone multi-frequency (DTMF) receiver for use in detecting digitally transmitted signals in the telephone industry. The receiver derives linear predictive coefficients for the digital signals in the data frame. This information is used to compute frequency response magnitudes at the DTMF frequencies. A plurality of magnitude comparisons are then performed to verify the presence of true DTMF signals and concurrently the frequency of these signals is obtained.
公开/授权文献
- US5669976A CVD method and apparatus therefor 公开/授权日:1997-09-23