Optical distribution system

• US 5,301,056 A
• Filed: 08/16/1993
• Issued: 04/05/1994
• Est. Priority Date: 12/16/1991
• Status: Expired due to Term

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: O'Neill, Frank P.
• Primary Examiner(s): PASCAL, LESLIE C
• Application Number:
  US08/107,046
• Time in Patent Office: 232 Days
• Field of Search: 359/123, 359/127, 359/135, 359/138, 359/145, 359/113, 359/115, 359/124, 359/125, 359/132, 359/137, 359/140, 359/153, 359/172
• US Class Current: 398/115
• CPC Class Codes: H04B 10/25754 Star network topology
• CPC Class Codes: H04J 14/0298 with sub-carrier multiplexing [SCM]

Abstract

A downlink portion consists of a multiplexer for combining several signals. The combined signal is converted to an optical signal by a laser and transmitted over an optical line to a splitter. The split signals are each transmitted to a detector which converts the optical signals back into an electrical signal. The electrical signal is then filtered to provide the desired signal from the combined signal. The desired signal is then transmitted. The uplink portion consists of a plurality of receivers which receive signals from remote units. The received signals are multiplexed and converted to optical signals in a laser. The optical signals are transmitted over optical lines to a combiner which provides a single combined optical signal. The combined optical signal is then transmitted over optical lines to a detector which converts the optical signals to an electrical signal. The electrical signal is then demultiplexed into its constituent portions.

Claims

1. An optical distribution system having a downlink portion and an uplink portion, said downlink portion comprising:

multiplexing means for combining a plurality of RF signals into a combined RF output signal;

first transducer means for converting said combined RF output signal to an optical signal;

a first optical link having a first end coupled to receive said optic signal;

first splitting means for splitting said optic signal into a plurality of optic signals, said first splitting means having an input coupled to a second end of said first optical link and a plurality of outputs;

a plurality of second optical links each having a first end coupled to one of said plurality of outputs of said first splitting means and a second end;

a plurality of first detector means for converting one of said plurality of optic signals back into said combined RF signal, each of said plurality of first detector means having an input coupled to a second end of one of said plurality of second optical links and an output;

a plurality of first converting means for isolating a first desired RF signal from said combined RF signal, each of said plurality of first converting means having an input coupled to said output of one of said plurality of first detector means;

a plurality of first transmitting means each coupled to said output of one of said plurality of first converting means for transmitting said desired RF signals;

second transducer means converting said combined RF signal into a second optic signal, said second transducer means having an input coupled to said output of one of said plurality of detector means;

second detector means for converting said second optic signal back into said combined RF signal, said second detector means having an input coupled to an output of said second transducer means;

second converting means for isolating a second desired RF signal from said combined RF signals, said second converting means having an input coupled to an output of said second detector means; and

second transmitting means for transmitting said second desired RF signal, said second transmitting means having an input coupled to an output of said second converting means.

2. The downlink portion of the optical distribution system of claim 1 wherein said multiplexing means is a time multiplexing means.

3. The downlink portion of the optical distribution system of claim 1 wherein said multiplexing means is a frequency multiplexing means.

4. The downlink portion of the optical distribution system of claim 1 wherein said first optical link and said plurality of second optical links are each a fiber optic cable.

5. The downlink portion of the optical distribution system of claim 1 wherein said each of said plurality of first converting means comprises:

demultiplexing means for dividing said combined RF signal into a plurality of individual RF signals; and

filter means for filtering one of said individual RF signals to provide said desired RF signal.

6. The downlink portion of the optical distribution system of claim 5 wherein said demultiplexing means is a selective demultiplexing means.

7. The downlink portion of the optical distribution system of claim 1 wherein each of said plurality of first transmitting means comprises an antenna.

8. The downlink portion of the optical distribution system of claim 1 further comprising:

second transducer means converting said combined RF signal into a second optic signal, said second transducer means having an input coupled to said output of one of said plurality of detector means;

second splitting means for splitting said optic signal into a plurality of optic signals, said first splitting means having an input coupled to said second end of said first optical link and a plurality of outputs;

a plurality of third optical links each having a first end coupled to one of said plurality of outputs of said second splitting means and a second end;

a plurality of second detector means for converting one of said plurality of optic signals back into said combined RF signal, each of said plurality of second detector means having an input coupled to a second end of one of said plurality of third optical links and an output;

a plurality of second converting means for isolating a second desired RF signal from said combined RF signal, each of said plurality of second converting means having an input coupled to said output of one of said plurality of second detector means; and

a plurality of second transmitting means each coupled to said output of one of said plurality of second converting means for transmitting said desired RF signals.

9. An optical distribution system having a downlink portion and an uplink portion, said uplink portion comprising:

a plurality of first receiving means for receiving an RF signal;

p1 a plurality of multiplexing means for multiplexing each received RF signal, each having an input coupled to an output of one of said plurality of first receiving means;

a plurality of first transducer means for converting each multiplexed RF signal to an optical signal, each first transducer means having an input coupled to an output of one of said plurality of multiplexing means;

a plurality of first optical links, each having a first end coupled to an output of one of said plurality of transducer means and a second end;

a plurality of first detecting means for converting each optical signal to an electrical signal, each having an input coupled to said second end of one of said plurality of first optical links and each having an output;

combining means for combining a plurality of input signals and producing an output signal, said combining means having a plurality of inputs, each coupled to one of said outputs of said plurality of first detecting means;

second transducer means for converting an electrical signal to an optical signal, said second transducer means having an input coupled to an output of said combining means;

a second optical link having a first end coupled to an output of said second transducer means and a second end;

second detecting means for converting an optical signal to an electrical signal, said second detecting means having an input coupled to said second end of said second optical link; and

demultiplexing means for demultiplexing a received signal into a plurality of output signals, said demultiplexing means having an input coupled to an output of said second detecting means and an output.

10. The uplink portion of the optical distribution system of claim 9 wherein said plurality of first optical links and said second optical link are each a fiber optic cable.

11. The uplink portion of the optical distribution system of claim 9 wherein said plurality of first transducer means each comprises a laser.

12. The uplink portion of the optical distribution system of claim 9 wherein said plurality of multiplexing means are each a time multiplexing means.

13. The uplink portion of the optical distribution system of claim 9 wherein said plurality of multiplexing means are each a frequency multiplexing means.

14. An optical distribution system having an uplink portion, downlink portion and a transceiver, said transceiver comprising:

antenna means for one of receiving and transmitting an RF signal;

duplexing means coupled to said antenna for one of coupling a downlink signal received from said downlink portion to said antenna and coupling an uplink signal received form said antenna to said uplink portion, said duplex means having an input and an output;

first mixing means for combining said uplink signal with a timing adjustment signal, said first mixing means having a first input coupled to said output of said duplexing means, a second input coupled to receive said timing adjustment means, and an output;

first transducer means for converting an electrical signal to an optical signal, said first transducer means having an input coupled to said output of said first mixing means and an output coupled to said uplink portion;

first detector means for converting an optical signal to an electrical signal, said first detector means having an input coupled to said downlink portion and an output; and

second mixing means for combining said downlink signal with said timing adjustment signal, said second mixing means having a first input coupled to said output of said first detector means, a second input coupled to receive said timing adjustment signal, and an output coupled to said input of said duplexing means.

15. The transceiver of the optical distribution system of claim 14 further comprising:

a pre-amplifier having an input coupled to said output of said duplexer and an output coupled to said first input of said first mixing means; and

filter means for filtering a signal, said filter means having an input coupled to said output of said first mixing means and an output coupled to said input of said first transducer means.

16. The transceiver of the optical distribution system of claim 14 further comprising:

first filter means for filtering a signal, said first filter means having an input coupled to said output of said first detector means and an output coupled to said first input of said second mixing means;

second filter means for filtering a signal, said first filter means having an input coupled to said output of said second mixing means and an output;

a low noise amplifier having an input coupled to said output of said second filter means and an output; and

a power amplifier having an input coupled to said output of said low noise amplifier and an output coupled to said input of said duplexing means.

17. The transceiver of the optical distribution system of claim 14 further comprising:

a pilot having an input coupled to said output of said first detector means and an output;

first synthesizer means for synthesizing a signal, said first synthesizer means having an input coupled to said output of said pilot, an output, and a feedback input;

oscillator means for providing an oscillating signal, said oscillator means having an input coupled to said output of said first synthesizer, a feedback output coupled to said feedback input of said first synthesizer, and an output;

second synthesizer means for synthesizing a signal, said second synthesizer means having an input coupled to said output of said oscillating means and an output; and

a voltage controlled oscillator having an input coupled to said output of said second synthesizer and an output coupled to said second inputs of said first and second mixing means.

18. The transceiver of the optical distribution system of claim 14 further comprising:

summing means for combining a plurality of signals, said summing means having a first input coupled to said output of said first mixing means, a second input, and an output coupled to said input of said first transducer means; and

second detector means for converting an optical signal to an electrical signal, said second detector having an output coupled to said second input of said summing means.

19. The transceiver of the optical distribution system of claim 14 further comprising:

a notch filter having an input coupled to said output of said first detector means and an output; and

second transducer means for converting an electrical signal to an optical signal, said second transducer having an input coupled to said output of said notch filter.