发明名称 |
Digital to analog conversion using nonuniform sample rates |
摘要 |
PCT No. PCT/US94/10269 Sec. 371 Date Aug. 29, 1996 Sec. 102(e) Date Aug. 29, 1996 PCT Filed Sep. 13, 1994 PCT Pub. No. WO95/08221 PCT Pub. Date Mar. 23, 1995A method and apparatus for digital to analog conversion using sigma-delta modulation of the temporal spacing between digital samples. The method and apparatus of the present invention provides for sigma-delta modulation of the time base such that errors produced by nonuniform sampling are frequency-shaped to a region (i.e., shifted to higher frequencies) where they can be removed by conventional filtering techniques In one embodiment, the digital data is interpolated by a fixed ratio and then decimated under control of a sigma-delta modulated frequency selection signal that represents, on average, the data rate of the incoming digital data stream. In another embodiment, the digital data is interpolated under control of a sigma-delta modulated frequency selection signal that represents, on average, the data rate of the incoming digital data stream and then decimated by a fixed ratio. The frequency signal selection number is modulated using an n-th order m-bit sigma-delta modulator. Data thus emerges from the interpolation/decimation process at the clock rate of the n-th order m-bit sigma-delta modulator. The method and apparatus converts the data rate of the incoming digital data stream to the data rate of the n-th order m-bit sigma-delta modulator.
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申请公布号 |
US5712635(A) |
申请公布日期 |
1998.01.27 |
申请号 |
US19960612944 |
申请日期 |
1996.08.29 |
申请人 |
WILSON, JAMES;CELLINI, RONALD A.;SOBOL, JAMES M. |
发明人 |
WILSON, JAMES;CELLINI, RONALD A.;SOBOL, JAMES M. |
分类号 |
H03M1/66;H03H17/06;H03L7/08;H03L7/093;H03L7/099;H03M3/02;H03M7/36;(IPC1-7):H03M1/66 |
主分类号 |
H03M1/66 |
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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