发明申请
US20040261120A1 Digital signal processing scheme for high performance HFC digital return path system with bandwidth conservation
有权
数字信号处理方案，用于具有带宽保护的高性能HFC数字返回路径系统
- 专利标题： Digital signal processing scheme for high performance HFC digital return path system with bandwidth conservation
- 专利标题（中）： 数字信号处理方案，用于具有带宽保护的高性能HFC数字返回路径系统
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申请号： US10465326申请日： 2003-06-18
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公开(公告)号： US20040261120A1公开(公告)日： 2004-12-23
- 发明人: Mao Zhu Zhang , Robert L. Howald
- 申请人： General Instrument Corporation
- 申请人地址： null
- 专利权人： General Instrument Corporation
- 当前专利权人： General Instrument Corporation
- 当前专利权人地址： null
- 主分类号： H04N007/173
- IPC分类号： H04N007/173 ; H04N007/16
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 null-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.