Digital optical transmitter
First Claim
1. In a cable television (CATV) system having a headend that provides video and data to a plurality of subscriber equipment via hybrid fiber/coax (HFC) network that includes a fiber portion, a first coax portion, a second coax portion, and a node for connecting the fiber portion to the first and second coax portions, a reverse path optical transmitter for use in the node, said reverse path transmitter comprising:
- a first input port for receiving a first plurality of reverse RF signals from a first portion of said plurality of subscriber equipment in said first coax portion;
a first analog-to-digital converter for converting said first reverse RF signal into a first reverse parallel digital signal;
a first parallel-to-serial converter for converting said first reverse parallel digital signal into a first reverse serial digital signal;
a second input port for receiving a second plurality of reverse RF signals from a second portion of said plurality of subscriber equipment in said second coax portion;
a second analog-to-digital converter for converting said second reverse RF signal into a second reverse parallel digital signal;
a second parallel-to-serial converter for converting said second reverse parallel digital signal into a second reverse serial digital signal;
an interleaver for interleaving said first and second reverse serial digital signals to form a single reverse digital signal;
a laser diode for converting said single reverse serial digital signal into a reverse digital optical signal; and
an output for transmitting said reverse digital optical signal to said headend over said fiber portion of said HFC network.
2 Assignments
0 Petitions
Accused Products
Abstract
A cable television system (100) having forward and reverse paths includes, in the reverse path, a digital optical transmitter (200) for receiving an RF signal, converting it to a digital signal, and adding a digital pilot tone thereto. A laser is driven in accordance with the summed digital signal to generate a digital optical signal representative of the pilot tone and the RF signal. The cable television system (100) also includes an optical receiver (305)for receiving the digital optical signal and recovering therefrom the RF signal and the pilot tone. The optical transmitter (200) and receiver (305) are coupled by fiber optic communication media (110).
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Citations
4 Claims
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1. In a cable television (CATV) system having a headend that provides video and data to a plurality of subscriber equipment via hybrid fiber/coax (HFC) network that includes a fiber portion, a first coax portion, a second coax portion, and a node for connecting the fiber portion to the first and second coax portions, a reverse path optical transmitter for use in the node, said reverse path transmitter comprising:
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a first input port for receiving a first plurality of reverse RF signals from a first portion of said plurality of subscriber equipment in said first coax portion;
a first analog-to-digital converter for converting said first reverse RF signal into a first reverse parallel digital signal;
a first parallel-to-serial converter for converting said first reverse parallel digital signal into a first reverse serial digital signal;
a second input port for receiving a second plurality of reverse RF signals from a second portion of said plurality of subscriber equipment in said second coax portion;
a second analog-to-digital converter for converting said second reverse RF signal into a second reverse parallel digital signal;
a second parallel-to-serial converter for converting said second reverse parallel digital signal into a second reverse serial digital signal;
an interleaver for interleaving said first and second reverse serial digital signals to form a single reverse digital signal;
a laser diode for converting said single reverse serial digital signal into a reverse digital optical signal; and
an output for transmitting said reverse digital optical signal to said headend over said fiber portion of said HFC network. - View Dependent Claims (2, 3, 4)
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Specification