Return path transmitter with extended digital processing circuitry
First Claim
1. A return path transmitter for use in conjunction with a local system that generates an analog RF data signal to be conveyed to a head end system, the return path transmitter comprising:
- an RF signal receiver configured to receive and convert the analog RF data signal into digitized RF data samples, the RF signal receiver further configured to output a first data stream including the digitized RF data samples;
digital processing circuitry configured to digitally process the first data stream and create corresponding digitally processed data;
a summing circuit configured to sum the corresponding digitally processed data of the first data stream to create a combined digital data stream; and
an optical transmitter configured to convert the combined digital data stream into a first optical data signal for transmission over an optical fiber to the head end system.
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Accused Products
Abstract
A Cable Television (CATV) digital return link system that provides dedicated, high-speed, full-duplex and point-to-point connections between users and the head end system is disclosed. The CATV digital return link system includes return path transmitters, intermediate hubs and a head end hub coupled to each other via a network of fiber optic cables. The return path transmitters are each coupled to a relatively large number of users via a local CATV-subtree. Signals from cable modems are transmitted via the local CATV-subtree to the return path transmitters for transmission to the head end. The return path transmitters include circuitry for digitally processing the RF data from the subtree prior to transmitting the RF data to the head end.
67 Citations
29 Claims
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1. A return path transmitter for use in conjunction with a local system that generates an analog RF data signal to be conveyed to a head end system, the return path transmitter comprising:
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an RF signal receiver configured to receive and convert the analog RF data signal into digitized RF data samples, the RF signal receiver further configured to output a first data stream including the digitized RF data samples;
digital processing circuitry configured to digitally process the first data stream and create corresponding digitally processed data;
a summing circuit configured to sum the corresponding digitally processed data of the first data stream to create a combined digital data stream; and
an optical transmitter configured to convert the combined digital data stream into a first optical data signal for transmission over an optical fiber to the head end system. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A return path transmitter for use in conjunction with a local system that generates an analog RF data signal to be conveyed to a head end system, the return path transmitter comprising:
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an RF signal receiver configured to receive and convert the analog RF data signal into digitized RF data samples, the RF signal receiver further configured to output a first data stream including the digitized RF data samples;
an optical transmitter configured to convert the first data stream into a first optical data signal for transmission over an optical fiber to the head end system; and
digital processing circuitry configured to determine a signal strength of the RF data signal by reference to the first data stream and compute an analog amplification level for the RF data signal by reference to the signal strength. - View Dependent Claims (18, 19)
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20. A return path transmitter for use in conjunction with a local system that generates an analog RF data signal to be conveyed to a head end system, the return path transmitter comprising:
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an RF signal receiver configured to receive and convert the analog RF data signal into digitized RF data samples, the RF signal receiver further configured to output a first data stream including the digitized RF data samples;
digital processing circuitry configured to shape the first data stream in a frequency domain; and
an optical transmitter configured to then convert the first data stream into a first optical data signal for transmission over an optical fiber to the head end system. - View Dependent Claims (21, 22, 23, 24, 25, 26)
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27. A return path transmitter for use in conjunction with a local system that generates an analog RF data signal to be conveyed to a head end system, the return path transmitter comprising:
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an RF signal receiver configured to receive and convert the analog RF data signal into digitized RF data samples, the RF signal receiver further configured to output a first data stream including the digitized RF data samples;
an optical transmitter configured to convert the first data stream into a first optical data signal for transmission over an optical fiber to the head end system; and
digital processing circuitry configured to perform a spectrum analysis of the first data stream and detect an ingress problem by reference to said spectrum analysis.
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- 29. The return path transmitter of claim 29, wherein the digital processing circuitry is further configured to compute a reduced analog amplification level for the RF data signal upon detecting the ingress problem.
Specification