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US 11,689,283 B1Granted
Free-space optical communication system using a backchannel for power optimization
AssigneeMeta Platforms, Inc.
InventorsStephen Philip Efthyvoulos, Eric Douglas Miller, Chien-Chung Chen, Slaven Moro
Life of this patent
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Abstract
An example device may include an optical modulator configured to generate an optical beam encoding network data, an optical power amplifier configured to adjust a transmitted power of the optical beam, and a transmit beam angle mechanism configured to adjust a beam direction of the optical beam and to transmit the optical beam to a remote receiver over a free-space optical link. Example devices may include a controller configured to receive backchannel data from the remote receiver and modify a characteristic of the optical beam based on the backchannel data. Various other devices, systems, and methods are also disclosed.
Claims15
A device comprising:
- an optical modulator configured to generate an optical beam, wherein the optical beam encodes network data and has a beam intensity, a beam direction and a carrier frequency;
- an optical power amplifier configured to adjust a transmitted power of the optical beam;
- a transmit beam angle mechanism, configured to:
- adjust the beam direction;
- and
- transmit the optical beam to a remote receiver over a free-space optical link;
- and
- a controller, configured to:
- receive backchannel data from the remote receiver comprising a received power, a bit error rate, and a carrier frequency offset between local oscillator frequencies used by the device and the remote receiver;
- and
- modify a plurality of characteristics of the optical beam based on the backchannel data, the plurality of characteristics comprising:
- adjustment of the beam intensity to maintain the bit error rate at a level that is correctable by the remote receiver while not further increasing the beam intensity;
- and
- adjustment of the carrier frequency to reduce the carrier frequency offset,
- wherein the carrier frequency offset is a difference between a local oscillator frequency of the device and a second local oscillator frequency of the remote receiver and is minimized to reduce the transmitted power of the optical beam for the bit error rate.
12 more elements
A device comprising:
- an optical amplifier, configured to receive an optical beam from a remote transmitter over a free-space optical link;
- an optical demodulator, configured to demodulate the optical beam and generate network data from the optical beam;
- and
- a terminal controller, configured to:
- determine at least one characteristic of the optical beam;
- and
- transmit backchannel data to the remote transmitter including the at least one characteristic of the optical beam, wherein the backchannel data comprises a received power, a bit error rate, and a carrier frequency offset between local oscillator frequencies used by the device and the remote transmitter;
- and
- wherein the device is further configured to:
- transmit a second optical beam to the remote transmitter;
- and
- receive remote backchannel data from the remote transmitter, and based on the remote backchannel data:
- adjust a second beam intensity of the second optical beam to maintain a second bit error rate that is correctable by the remote transmitter while not further increasing the beam intensity;
- and
- adjust a second carrier frequency of the second optical beam to reduce the carrier frequency offset, wherein:
- the carrier frequency offset is a difference between a local oscillator frequency of the device and a second local oscillator frequency of the remote receiver and is minimized to reduce the transmitted power of the optical beam for the bit error rate.
13 more elements
A method, comprising:
- receiving, at a communication terminal, a communication signal over a free-space optical link from a remote communication terminal;
- determining, at the communication terminal, at least one characteristic of the communication signal;
- transmitting, from the communication terminal to the remote communication terminal, backchannel data including an indication of the at least one characteristic of the communication signal, wherein the backchannel data comprises a received power, a bit error rate, and a carrier frequency offset between a local oscillator frequencies used by the communication terminal and the remote communication terminal;
- and
- modifying, at the remote communication terminal, the communication signal based on the backchannel data, wherein:
- the communication signal comprises an optical beam;
- modifying the communication signal comprises:
- adjustment of a beam intensity of the optical beam to maintain the bit error rate at a value that is correctable by the communication terminal while not further increasing the beam intensity;
- and
- adjustment of the carrier frequency of the optical beam to reduce a carrier frequency offset between the communication terminal and the remote communication terminal;
- and
- the carrier frequency offset is a difference between a local oscillator frequency of the device and a second local oscillator frequency of the remote receiver and is minimized to reduce the transmitted power of the optical beam for the bit error rate.
9 more elements
Dependencies are inferred from the claim text.