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
WO2004114058(A2)
申请公布日期
2004.12.29
申请号
WO2004US18337
申请日期
2004.06.08
申请人
GENERAL INSTRUMENT CORPORATION, A CORPORATION OF THE STATE OF DELAWARE;ZHANG, MAO, ZHU;HOWALD, ROBERT, L.