US 2006/0067698 A1Published application

Optical fiber system and method for carrying both CATV and Ethernet signals

AssigneeNational Central University

InventorsYi-Jen Chan, Fan-Hsiu Huang, Hsin-Pin Wang, Dong-Min Lin, Mu-Tao Chu, Shin-Ge Lee, Shun-Tien Lee

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Abstract

The present invention is an optical fiber system and method for carrying both CATV and Ethernet signals. The digital signals are translated into higher band by a direct up/down conversion so that analog signals and digital signals are treated as different frequency bands of electrical signals. Then, all the signals are mixed/divided by a power combiner/divider. And then, by using optoelectronic devices, the signals are processed with optoelectronic conversion. The converted optical signals are transmitted in a fiber or a related optical channel having low channel loss yet high capacity. To sum up, the present invention can transmit digital signals together with analog signals in a single wavelength to save the cost of an optical signal system and to provide a convenience on rearranging the system.

Claims23

Dependent claims

An optical fiber system for carrying both CATV (cable television) and Ethernet signals, comprising a transmitting part, an optical channel and a receiving part, said transmitting part comprising

(1) a first transmitter;
(2) a second transmitter comprising a transmitting signal source, a radio-frequency carrier, a mixer for transmission and a band-pass filter;
and
(3) a combiner amplifier,
said receiving part comprising
(1) a receiver divider;
(2) a first receiver;
and
(3) a second receiver comprising a receiving signal source, a high-pass filter, a down-converter carrier, a mixer for receipt, a low-pass filter, a limiting amplifier and a signal output,
wherein, by said combiner amplifier,
(1) a signal from said first signal transmitter and a signal from said second signal transmitter are combined to form a mixed signal and
(2) said mixed signal is adjusted in level and power and
(3) said mixed signal is modulated into an optical signal;
wherein, by said receiver divider, said optical signal is divided into a signal for a first receiver and a signal for a second receiver;
and
wherein said transmitting part are connected to said receiving part by said optical channel.

13 more elements

A method for carrying both CATV and Ethernet signals over an optical fiber system, comprising steps of which:

(A) in a transmitting part,
(1) a signal of a first signal source is transmitted to a low-pass filter for transmission and then is transmitted to a power combiner;
(2) a signal of a second signal source is up-converted by a mixer for transmission and then is transmitted to a band-pass filter and then said signal is transmitted to said power combiner;
(3) said signal of said first signal source and said signal of said second signal source are combined by said power combiner to form a mixed electrical signal;
(4) the level and the power of said mixed electrical signal are modulated by an amplifier for transmission;
and
(5) said mixed electrical signal is converted into an optical signal by an electrical-to-optical converter, and
(B) said optical signal is transmitted by an optical channel, and,
(C) in a receiving part,
(1) said optical signal is received from said optical channel into an optical-to-electrical converter to be converted into said mixed electrical signal;
(2) by a power divider, said mixed electrical signal is divided into a signal of a third signal source and a signal of a fourth signal source;
(3) said signal of said third signal source is transmitted to a low-pass filter for receipt to be transmitted to a signal amplifier and then is outputted as a first signal output;
and
(4) said signal of said fourth signal source is transmitted to a high-pass filter and is transmitted to a mixer for receipt so as to be down-sampled into a enveloped signal, and said pocketed signal is unpacked into a non-pocketed signal through a low-pass filter for unpacking, and said non-pocketed signal is amplified by a limiting amplifier to be outputted as a second signal output.

11 more elements

Dependencies are inferred from the claim text.