发明名称 |
ADPCM Encoder/decoder with signalling bit insertion |
摘要 |
In an ADPCM transmission system, signalling frames of an incoming multiplexed PCM signal are identified and signalling bits extracted therefrom. During each signalling frame, an ADPCM encoder/decoder is controlled by the signalling frame signal to operate entirely for 3-bit ADPCM, instead of the regular 4-bit ADPCM, to which 3-bit ADPCM the extracted signalling bits are added for transmission. The deliberate alteration from 4-bit to 3-bit ADPCM at the encoder and decoder of the system in each signalling frame ensures proper adaptation and consequently no loss of tracking between the encoder and the decoder.
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申请公布号 |
US4549304(A) |
申请公布日期 |
1985.10.22 |
申请号 |
US19830555359 |
申请日期 |
1983.11.28 |
申请人 |
NORTHERN TELECOM LIMITED |
发明人 |
WEIRICH, ANDREAS H.;STRAWCZYNSKI, LEO |
分类号 |
H04B14/06;(IPC1-7):H04J3/02 |
主分类号 |
H04B14/06 |
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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