Systems and methods for multiplexing and demodulation at high frequencies and increased communication bandwidth

Patent metadata

Field	Value
Publication number	US-2018270010-A1
Application number	US-201815921478-A
Country	US
Kind code	A1
Filing date	Mar 14, 2018
Priority date	Mar 14, 2017
Publication date	Sep 20, 2018
Grant date	—

Abstract

Free-space communication systems and methods are provided. The systems include a transmitter that combines multiple sets of radio-frequency-modulated optical carrier frequencies for transmission across free space using multiple transmission apertures. Different sets of signals are filtered to form single sideband signals. The different sets of single sideband signals are then combined to form dense wavelength division multiplexed signals. In addition, combined sets of signals of different polarizations can be combined. A receiver can include a single receive aperture.

First claim

What is claimed is:

1 . A communication system, comprising:
a transmitter, including:
a plurality of light sources, wherein each light source is operable to output at least one optical carrier frequency;
a plurality of modulators, wherein each carrier frequency is associated with a modulator, and wherein each modulator is operable to modulate the associated carrier frequency with a radio frequency signal, wherein the modulators form modulated signals;
a plurality of multiplexers, wherein each multiplexer is operable to combine modulated signals from at least two of the modulators, wherein the multiplexers form wavelength division multiplexed signals;
a plurality of interleavers, wherein each interleaves: is operable to combine wavelength division multiplexed signals from at least two of the multiplexers, wherein the interleavers form sets of interleaved signals; and
free space optics, wherein the sets of interleaved signals are output by the free space optics.

2 . The communication system of claim 1 , further comprising:
beam control optics, wherein the beam control optics include a plurality of transmit apertures, wherein each transmit aperture is operable receive the signals from the multiplexers and to output at least one of the sets of interleaved signals to the free space optics.

3 . The communication system of claim 2 , wherein each transmit aperture outputs a different set of interleaved signals to the free space optics.

4 . The communication system of claim 3 , wherein the combined modulated signals from a first modulator in the plurality of modulators have a first polarization.

5 . The communication system of claim 4 , wherein the combined modulated signals from a second modulator in the plurality of modulators have the first polarization, wherein the combined modulated signals from a third modulator in the plurality of modulators have a second polarization, wherein the combined modulated signals from a fourth modulator in the plurality of modulators have the second polarization.

6 . The communication system of claim 5 , further comprising:
a plurality of polarization combiners, wherein an input of each polarization combiner is connected to an output of each of at least two associated interleavers.

7 . The communication system of claim 4 , wherein for each polarization combiner the interleaved signals from a first one of the associated interleavers have the first polarization and the interleaved signals from a second one of the associated interleavers have a second polarization.

8 . The communication system of claim 7 , wherein an output of a first polarization combiner in the plurality of polarization combiners is connected to a first transmit aperture included in the plurality of transmit apertures, and wherein an output of a second polarization combiner in the plurality of polarization combiners is connected to a second transmit aperture included in the plurality of transmit apertures.

9 . The communication system of claim 8 , wherein the transmitter includes four transmit apertures.

10 . The communication system of claim 9 , further comprising:
a plurality of optical amplifiers, wherein each multiplexer is associated with at least one of the optical amplifiers, and wherein each optical amplifier provides an output that is received at an input of a corresponding interleaver.

11 . The communication system of claim 1 , further comprising:
a receiver, wherein the receiver includes a single receiver aperture, and wherein at least the first and second sets of interleaved signals transmitted from the plurality of transmit apertures of the transmitter are received by the single aperture of the receiver.

12 . The communication system of claim 11 , wherein the transmitter is ground-based, and wherein the receiver is space-based.

13 . The communication system of claim 1 , wherein each modulator is operable to modulate a carrier frequency received from a corresponding light source with a radio frequency carrier signal and a radio frequency information signal.

14 . A communication system, comprising:
a plurality of transmission sub-assemblies, wherein each transmission sub-assembly includes:
a light source, wherein the light source includes an output, and wherein the light source is operable to output light of a selected wavelength;
a radio frequency input;
a modulator, wherein the modulator includes a first input that is connected to the output of the light source, wherein the modulator includes a second input that is operable to receive a radio frequency signal, and wherein the modulator is operable to modulate the light of the selected wavelength received from the light source with the radio frequency signal to form a modulated signal;
a filter, wherein the filter is operable to remove a first side of the modulated signal to form a channel;
a plurality of multiplexers, wherein each multiplexer in the plurality of multiplexers receives communication signals from a plurality of the transmission sub-assemblies, and wherein each multiplexer in the plurality of multiplexers places a channel from each of the associated transmission sub-assemblies onto a single fiber optic element; a plurality of interleavers, wherein each interleaver is associated with a different pair of multiplexers in the plurality of multiplexers, and wherein each interleaver places channels from the associated pair of multiplexers onto a single fiber optic element.

15 . The communication system of claim 14 , further comprising:
a plurality of polarization combiners, wherein each polarization combiner is associated with a different pair of interleavers in the plurality of interleavers, wherein the channels from a first interleaver in the first pair of interleavers includes light of a first polarization, and wherein the channels from a second interleaver in the first pair of interleavers includes light of a second polarization.

16 . A communication method, comprising:
selecting a set of carrier wavelengths, wherein each carrier wavelength in the set of carrier wavelengths is spaced apart from a neighboring carrier wavelength by a selected amount; modulating a plurality of the carrier wavelengths in the set of carrier wavelengths to create a plurality of signals; multiplexing the plurality of signals, wherein at least first and second subsets of the signals in the plurality of signals are placed on at least first and second optical fibers; interleaving the first and second subsets of the plurality of signals, wherein the first and second subsets of the plurality of signals are placed on a third optical fiber.

17 . The method of claim 16 , further comprising:
combining signals in the plurality of signals having different polarizations, wherein the signals on the third optical fiber have a first polarization, wherein third and fourth subsets of the signals in the plurality of signals are placed on at least fourth and fifth optical fibers, wherein the third and fourth subsets of the plurality of signals are placed on a sixth optical fiber, wherein the signals on the sixth optical fiber have a second polarization, and wherein the signals from the third optical fiber and the signals from the sixth optical fiber are placed on a seventh optical fiber.

18 . The method of claim 17 , further comprising:
delivering the signals from the seventh optical fiber to a first sub-aperture of a first telescope; delivering signals from an eighth optical fiber to a second sub-aperture of the first telescope; and transmitting the signals from the

Assignees

• Ball Aerospace & Tech Corp

Inventors

• Troeltzsch John R
• Wilson Colin H
• Pierce Robert M
• Chase Holden
• Primeau Brian
• Kaliski Robert
• Staple Bevan D
• Marshalek Robert

Classifications

• H04J14/0213

  Groups of channels or wave bands arrangements · CPC title

• H04J14/0208

  Interleaved arrangements · CPC title

• H04B10/118

  specially adapted for satellite communication · CPC title

• H04J14/06 Primary

  Polarisation multiplex systems · CPC title

• H04J14/007

  Orthogonal Optical Code Multiplex · CPC title