Dynamic upstream attenuation for ingress noise reduction
4 Assignments
0 Petitions
Accused Products
Abstract
A dynamic arrangement for reducing the presence of ingress noise in the upstream signal path of a two-way cable system utilizes a variable attenuation element and amplifier disposed along the upstream signal path. The amplifier includes a bypass switch so that the amplifier may be switched in to or out of the upstream path. A signal processor associated with the communications gateway functions to calculate the upstream loss present at the gateway and control the operation of the attenuation element, amplifier and bypass switch accordingly. Upstream attenuation is selected to be as large as possible, yet still allow in-building cable devices to communicate with their associated head end (HE) receiver equipment, after accounting for maximum transmit limitations.
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Citations
17 Claims
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1-8. -8. (canceled)
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9. An apparatus for reducing the presence of ingress noise from a communications gateway, including an embedded cable modem, at a subscriber location, said communications gateway comprising an RF module containing separate upstream and downstream signal paths, the apparatus comprising:
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a variable attenuation element disposed in the upstream signal path in the RF module;
a signal processor configured to calculate the value of upstream loss as used in attenuation, said signal processor is further configured to control the operation of said variable attenuation element so as to reduce the presence of ingress noise in the upstream signal path, wherein the signal processor controls the attenuation level of said variable attenuation element such that when the calculated upstream loss is positive the attenuation is set to be essentially equal to said calculated upstream loss. - View Dependent Claims (10, 11, 12, 13, 14)
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15. A method of reducing the presence of ingress noise in the upstream path of a bidirectional cable system at a communications gateway located at a subscriber premises, the method comprising the steps of:
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calculating the upstream loss present at the communications gateway; and
if the calculated loss is positive, setting an upstream variable attenuation element to exhibit an attenuation equal to the calculated upstream loss value. - View Dependent Claims (16, 17)
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Specification