Beyer Weaver & Thomas, LLP
Method and apparatus for locating a cleaner bandwidth in a frequency channel for data transmission
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.
Cisco Technology, Inc.
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H04N H04N
inventional inventional
Alejandro H. Hung-San Xiong Charles J.
Schwartzman Chen Yang Naegeli