发明名称 |
Digital multi-line companded delta modulator |
摘要 |
A companded digital delta modulator which can encode both voice and voice band modem signals over a wide range of input levels is shown. The companding method or algorithm is based on measuring bit stream correlation and can be scaled to give substantially maximum performance over a wide range of signal types. The algorithm has a low sensitivity to digital channel errors, thus making it suitable for signal coding for satellite channels and the like. In addition, the digital design permits common hardware to simultaneously serve a large number of lines, thus permitting the substantial savings in the hardware cost per line. A further aspect of the invention concerns the ability to handle multiple bit delta modulation as well as single bit delta bit modulation in the above environment.
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申请公布号 |
US4059800(A) |
申请公布日期 |
1977.11.22 |
申请号 |
US19760701265 |
申请日期 |
1976.06.30 |
申请人 |
INTERNATIONAL BUSINESS MACHINES CORPORATION |
发明人 |
JONES, JR., GARDNER DULANY |
分类号 |
H03M3/02;H04B14/06;(IPC1-7):H04B1/00 |
主分类号 |
H03M3/02 |
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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