Methods of adaptive cancelling and secondary communications channels for extended capability HFC cable systems
First Claim
1. A method, comprising:
- obtaining a first set of information, and transmitting an RF modulated first set of information over a primary channel on a first segment of a conductive cable;
secondary channel modulating said first set of information, and transmitting said secondary-channel-modulated first set of information over a secondary channel;
obtaining a second set of information, and transmitting an RF modulated second set of information over said first segment;
at a junction connecting said first segment and a second segment of said conductive cable, obtaining said secondary-channel-modulated first set of information, and using said secondary-channel-modulated first set of information to create a reference signal to adaptively cancel said RF modulated first set of information, thereby preventing said RF modulated first set of information from crossing said junction, while permitting said RF modulated second set of information to cross said junction from said first segment to said second segment.
2 Assignments
0 Petitions
Accused Products
Abstract
A method to extend the downstream and upstream data carrying capability of an HFC CATV system. At the neighborhood level, the CATV cable (the primary channel) is divided into different segments connected by electrically active junctions. At the junctions, each segment is also connected to a secondary data channel, such as an optical fiber or ultrahigh RF frequency (1 GHz+) secondary channel, which can carry supplemental downstream narrowcast channels and upstream channels between a plurality of such CATV cable segments. At the junctions, some CATV primary channel RF signals such as broadcast channels are passed without interference, while certain primary channel downstream narrowcast RF channels and upstream narrowcast RF channels are precisely suppressed using adaptive cancelling methods. Such adaptive cancellation methods are superior to prior art lowpass, highpass, and bandpass filtering methods because they allow for more efficient use of limited CATV primary channel RF spectrum.
44 Citations
20 Claims
-
1. A method, comprising:
-
obtaining a first set of information, and transmitting an RF modulated first set of information over a primary channel on a first segment of a conductive cable; secondary channel modulating said first set of information, and transmitting said secondary-channel-modulated first set of information over a secondary channel; obtaining a second set of information, and transmitting an RF modulated second set of information over said first segment; at a junction connecting said first segment and a second segment of said conductive cable, obtaining said secondary-channel-modulated first set of information, and using said secondary-channel-modulated first set of information to create a reference signal to adaptively cancel said RF modulated first set of information, thereby preventing said RF modulated first set of information from crossing said junction, while permitting said RF modulated second set of information to cross said junction from said first segment to said second segment. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A method configurable in a node for connecting a first segment and a second segment of a conductive cable, comprising:
-
receiving primary channel signals on a primary channel from the first segment of the conductive cable, wherein the primary channel signals include a first set of signals and a second set of signals; receiving secondary channel signals on a secondary channel from the first segment, wherein the secondary channel signals include the second set of signals modulated for the secondary channel; using the secondary channel modulated second set of signals to create a reference signal to adaptively filter the second set of signals from the primary channel signals while passing through the first set of signals, thereby preventing the second set of signals from passing to the second segment of the conductive cable; and transmitting the first set of signals on the primary channel to the second segment of the conductive cable. - View Dependent Claims (12, 13, 14, 15, 16, 18, 19, 20)
-
-
17. A node configurable for adaptive cancellation, comprising:
-
at least one processor configured to; receive primary channel signals on a primary channel from the first segment of the conductive cable, wherein the primary channel signals include a first set of signals and a second set of signals; receive secondary channel signals on a secondary channel from the first segment, wherein the secondary channel signals include the second set of signals modulated for the secondary channel; and an adaptive canceller configured to; use the secondary channel modulated second set of signals to create a reference signal to adaptively filter the second set of signals from the primary channel signals while passing through the first set of signals from the primary channel signals, thereby preventing the second set of signals from passing to the second segment of the conductive cable; and a transmitter configured to; transmit the first set of signals on the primary channel to the second segment of the conductive cable.
-
Specification