发明名称 |
DIGITAL SIGNAL PROCESSING SCHEME FOR HIGH PERFORMANCE HFC DIGITAL RETURN PATH SYSTEM WITH BANDWIDTH CONSERVATION |
摘要 |
In a cable return path system, a method for performing digital companding adds a predetermined offset to the digital value to be companded, and employs a modified μ-law or a-law companding technique to obtain a reduced bit length digital value. One embodiment of this modified approach adds a predetermined offset (e.g., 129 for a 12-bit implementation) to the digital value before companding and then employs a two-bit chord and a 5-bit step for the 12-bit implementation. The end result is that the performance metrics are not significantly compromised by this bit reduction when compared to current transmission methods without this technique. |
申请公布号 |
EP1634144(A4) |
申请公布日期 |
2008.07.02 |
申请号 |
EP20040776398 |
申请日期 |
2004.06.08 |
申请人 |
GENERAL INSTRUMENT CORPORATION |
发明人 |
ZHANG, MAO, ZHU;HOWALD, ROBERT, L. |
分类号 |
H03M7/50;H03M7/00;H03M7/30;H03M7/46;H04N7/173;H04N7/22 |
主分类号 |
H03M7/50 |
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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