发明名称 Method and apparatus for locating a cleaner bandwidth in a frequency channel for data transmission
摘要 Apparatus, methods, and computer program products for utilizing a frequency channel determined to be unacceptably noisy by finding a cleaner, narrower bandwidth within the frequency channel. Initially data is received on a frequency channel at a CMTS, specifically an upstream receiver, and by a narrow bandwidth detector, connected to a processor also used by components in the CMTS. The narrow bandwidth detector performs a Fast Fourier Transform (FFT) on the frequency channel thereby creating multiple FFT points within the frequency channel. A clean bandwidth for transmitting data within the frequency channel is identified where the clean bandwidth is derived from a subset of FFT points from the full set of FFT points. The subset of FFT points are contiguous points that have a noise level below a predetermined noise threshold.
申请公布号 US6574797(B1) 申请公布日期 2003.06.03
申请号 US19990227991 申请日期 1999.01.08
申请人 CISCO TECHNOLOGY, INC. 发明人 NAEGELI CHARLES J.;CHEN HUNG-SAN;SCHWARTZMAN ALEJANDRO H.;YANG XIONG
分类号 H04N7/173;H04N17/00;(IPC1-7):H04N7/173;H04B1/10;H04B3/46;H04J3/16;H04N11/00 主分类号 H04N7/173
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