Tunable RF return path filter with automatic channel plan detection

摘要

A method and computing device that provides a tunable RF filter for a two-way communication system. The method receives a downstream video signal, and filters the downstream video signal into at least one downstream bandwidth band, each downstream bandwidth band related to desired upstream/downstream bandwidth splits. The method performs an energy detection on each downstream bandwidth band, and determines a lowest frequency of said at least one downstream bandwidth band that contains downstream video content. The method sets a diplex filter upstream/downstream frequency cutoff to a maximum upstream bandwidth that does not conflict with the lowest frequency of said at least one downstream bandwidth band that contains downstream video content.

主权项

1. A method, comprising:
in a detection circuit, receiving an attenuated downstream communication signal for controlling a plurality of switches; using a plurality of bandpass filters to filter the attenuated downstream communication signal into a plurality of downstream bandwidth bands, each downstream bandwidth band related to a corresponding one of the plurality of switches and a corresponding available upstream/downstream bandwidth split; performing an energy detection on each downstream bandwidth band for determining whether a frequency of said downstream bandwidth band contains downstream communication content; and based on a result of the determining on each downstream bandwidth band, controlling the corresponding one of the plurality of switches to one of bypassing and enabling a corresponding low-pass filter of a diplex filter, such that the diplex filter is thereby configured to receive an upstream communication signal and to output a filtered upstream communication signal having a maximum upstream bandwidth that does not conflict with a lowest downstream frequency of said plurality of downstream bandwidth bands that contains downstream communication content.