US 2004/0001719 A1 · Optical transmission system of radio signal over optical fiber link

Abstract

In coupling a control station 11 transmitting a radio signal to a plurality of base stations each transmitting the radio signal to a terminal station by an optical fiber, and dependently connecting the plurality of base stations to the optical fiber, the control station 11 includes a radio signal transmitter 16 and an electrical-to-optical converter 17, each of the base stations 12 includes an SOA-EAM 18 comprises a semiconductor optical amplifier (SOA) and an electro-absorption modulator (EAM), a down link radio signal amplifier 19, and a down link antenna 20, the SOA-EAM 18 receiving an optical signal from the control station 11. It is possible to provide an optical transmission system which can prevent optical power from lowering even if the number of base stations increases and which can facilitate adding a base station since an optical coupler is not used.

Claims17

Dependent claims

An optical transmission system of radio signal over optical fiber link for a down link, comprising:

a control station;
and a plurality of base stations dependently connected to one another by an optical fiber, wherein
said control station comprises:
a radio signal transmitter transmitting a down electric signal;
and
an electrical-to-optical converter converting said down electric signal to a down optical signal, and outputting the down optical signal to said optical fiber, and
each of said base stations comprises:
an amplifier-converter converting said down optical signal to said down electric signal;
a radio signal amplifier amplifying said down electric signal;
and
a down link antenna transmitting said amplified down electric signal.

8 more elements

A optical transmission system of radio signal over optical fiber link for up and down links, comprising:

a control station;
and a plurality of base stations dependently connected to one another by an optical fiber, wherein
said control station comprises:
a radio signal transmitter-receiver transmitting a down electric signal, and receiving an up electric signal;
an electrical-to-optical converter converting said down electric signal to a down optical signal;
an optical-to-electrical converter inputting an up optical signal, and converting the up optical signal to said up electric signal;
and
an optical circulator sending said down optical signal from said electrical-to-optical converter to said optical fiber and said up optical signal from said optical fiber to said optical-to-electrical converter,
each of said base stations comprises:
an amplifier-converter converting said down optical signal input from said optical fiber to said down electric signal, converting said up electric signal to said up optical signal to output the converted up optical signal to said optical fiber;
an electric circulator changing said down electric signal output from said amplifier-converter to and from said up electric signal input to said amplifier-converter;
a radio signal amplifier amplifying said down electric signal;
a down link filter filtering said amplified down electric signal;
a down link antenna transmitting said down electric signal;
an up link antenna receiving said up electric signal;
an up link radio signal amplifier amplifying said up electric signal;
and
an up link filter filtering said amplified up electric signal, and
the terminal base station out of said plurality of base stations includes, in said optical fiber, a laser diode outputting light.

16 more elements

An optical transmission system of radio signal over optical fiber link for up and down links, comprising:

a control station;
and a plurality of base stations dependently connected to one another by an optical fiber laid in a ring form relative to said control station, wherein
said control station comprises:
a radio signal transmitter-receiver transmitting a down electric signal, and receiving an up electric signal;
an electrical-to-optical converter converting said down electric signal to a down optical signal;
an optical-to-electrical converter inputting an up optical signal, and converting the up optical signal to said up electric signal;
an optical circulator sending said down optical signal from said electrical-to-optical converter to said optical fiber to and from said up optical signal from said optical fiber to said optical-to-electrical converter;
and
a laser diode outputting a laser beam for modulating said up optical signal to said optical fiber, and
each of said base stations comprises:
an amplifier-converter converting said down optical signal input from said optical fiber to said down electric signal, converting said up electric signal to said up optical signal to output the converted up optical signal to said optical fiber;
an electric circulator changing said down electric signal output from said amplifier-converter to and from said up electric signal input to said amplifier-converter;
a radio signal amplifier amplifying said down electric signal;
a down link filter filtering said amplified down electric signal;
a down link antenna transmitting said down electric signal;
an up link antenna receiving said up electric signal;
an up link radio signal amplifier amplifying said up electric signal;
and
an up link filter filtering said amplified up electric signal.

16 more elements

Dependencies are inferred from the claim text.

Optical transmission system of radio signal over optical fiber link

Life of this patent

Optical transmission system of radio signal over optical fiber link

Life of this patent

Abstract

Claims17