Abstract: The disclosure provides a communication system that includes sensors, a plurality of components, and processors. The sensors receive measurements related to a state of the communication system. The processors receive an indication of an amount of received power at a remote communication system and estimate a state of the plurality of components based on the received one or more measurements and the received indication. Using the indication and the estimated state, the processors determine whether the amount of received power is likely to fall below a minimum received power within a given time interval. When it is likely, the processors select an adjustment technique of a plurality of adjustment techniques for adjusting a data rate of the outbound signal and adjust a given component of the communication system using the selected adjustment technique to change the data rate of the outbound signal.

Abstract: Aspects of the disclosure provide an optical communication system. The system may include a receiver lens system configured to receive a light beam from a remote optical communication system and direct the light beam to a photodetector. The system may also include the photodetector. The photodetector may be configured to convert the received light beam into an electrical signal, and the photodetector may be positioned at a focal plane of the receiver lens system. The system may also include a phase-aberrating element arranged with respect to the receiver lens system and the photodetector such that the phase-aberrating element is configured to provide uniform angular irradiance at the focal plane of the receiver lens system.

Abstract: Aspects of the disclosure provide an optical communication system. The system may include a receiver lens system configured to receive a light beam from a remote optical communication system and direct the light beam to a photodetector. The system may also include the photodetector. The photodetector may be configured to convert the received light beam into an electrical signal, and the photodetector may be positioned at a focal plane of the receiver lens system. The system may also include a phase-aberrating element arranged with respect to the receiver lens system and the photodetector such that the phase-aberrating element is configured to provide uniform angular irradiance at the focal plane of the receiver lens system.

Abstract: Aspects of the disclosure provide an optical communication system. The system may include a receiver lens system configured to receive a light beam from a remote optical communication system and direct the light beam to a photodetector. The system may also include the photodetector. The photodetector may be configured to convert the received light beam into an electrical signal, and the photodetector may be positioned at a focal plane of the receiver lens system. The system may also include a phase-aberrating element arranged with respect to the receiver lens system and the photodetector such that the phase-aberrating element is configured to provide uniform angular irradiance at the focal plane of the receiver lens system.

Abstract: Aspects of the disclosure provide an optical communication system. The system may include a receiver lens system configured to receive a light beam from a remote optical communication system and direct the light beam to a photodetector. The system may also include the photodetector. The photodetector may be configured to convert the received light beam into an electrical signal, and the photodetector may be positioned at a focal plane of the receiver lens system. The system may also include a phase-aberrating element arranged with respect to the receiver lens system and the photodetector such that the phase-aberrating element is configured to provide uniform angular irradiance at the focal plane of the receiver lens system.

Abstract: The disclosure may provide for a communication method and system. A transmitter of the communication system may include an interleaver and a first encoder for determining parity bits. The transmitter also may include a multiplexer for joining the parity bits with the data. A second encoder may be positioned after the multiplexer for implementing an error correcting code. A receiver of the communication system may include a decoder followed by an interleaver. When errors are detected in received data at the decoder, one or more processors of the receiver may be configured to correct portions of the received data and combine the corrected portions with the received data.

Abstract: The disclosure provides a communication system that includes sensors, a plurality of components, and processors. The sensors receive measurements related to a state of the communication system. The processors receive an indication of an amount of received power at a remote communication system and estimate a state of the plurality of components based on the received one or more measurements and the received indication. Using the indication and the estimated state, the processors determine whether the amount of received power is likely to fall below a minimum received power within a given time interval. When it is likely, the processors select an adjustment technique of a plurality of adjustment techniques for adjusting a data rate of the outbound signal and adjust a given component of the communication system using the selected adjustment technique to change the data rate of the outbound signal.

Abstract: Aspects of the disclosure provide techniques for automatic repeat request (ARQ) in a free-space optical communication (FSOC) architecture. These techniques, including block-selective ARQ, adaptive retransmission delay, and random seed scrambling, can be used individually or in combination to combat problems involving frame loss or corruption. These techniques enable the system to rapidly recover by streamlining the retransmission process. For instance, block-selective ARQ acknowledges variable length blocks of frames in the return stream from the receiver to the transmitter. Adaptive retransmission delay allows the retransmission delay to grow in the absence of feedback by the receiver, up to some defined limit. And with random seed sampling, a scrambling sequence is incorporated to aid with frame syncing, which avoids the need for a line code. These aspects of the technology provide a robust communication process, and also reduce overhead costs associated with unnecessary retransmissions.

Abstract: Aspects of the disclosure provide techniques for automatic repeat request (ARQ) in a free-space optical communication (FSOC) architecture. These techniques, including block-selective ARQ, adaptive retransmission delay, and random seed scrambling, can be used individually or in combination to combat problems involving frame loss or corruption. These techniques enable the system to rapidly recover by streamlining the retransmission process. For instance, block-selective ARQ acknowledges variable length blocks of frames in the return stream from the receiver to the transmitter. Adaptive retransmission delay allows the retransmission delay to grow in the absence of feedback by the receiver, up to some defined limit. And with random seed sampling, a scrambling sequence is incorporated to aid with frame syncing, which avoids the need for a line code. These aspects of the technology provide a robust communication process, and also reduce overhead costs associated with unnecessary retransmissions.

Abstract: The disclosure provides a communication system that includes sensors, a plurality of components, and processors. The sensors receive measurements related to a state of the communication system. The processors receive an indication of an amount of received power at a remote communication system and estimate a state of the plurality of components based on the received one or more measurements and the received indication. Using the indication and the estimated state, the processors determine whether the amount of received power is likely to fall below a minimum received power within a given time interval. When it is likely, the processors select an adjustment technique of a plurality of adjustment techniques for adjusting a data rate of the outbound signal and adjust a given component of the communication system using the selected adjustment technique to change the data rate of the outbound signal.

Abstract: Aspects of the disclosure provide techniques for automatic repeat request (ARQ) in a free-space optical communication (FSOC) architecture. These techniques, including block-selective ARQ, adaptive retransmission delay, and random seed scrambling, can be used individually or in combination to combat problems involving frame loss or corruption. These techniques enable the system to rapidly recover by streamlining the retransmission process. For instance, block-selective ARQ acknowledges variable length blocks of frames in the return stream from the receiver to the transmitter. Adaptive retransmission delay allows the retransmission delay to grow in the absence of feedback by the receiver, up to some defined limit. And with random seed sampling, a scrambling sequence is incorporated to aid with frame syncing, which avoids the need for a line code. These aspects of the technology provide a robust communication process, and also reduce overhead costs associated with unnecessary retransmissions.

Abstract: The disclosure may provide for a communication method and system. A transmitter of the communication system may include an interleaver and a first encoder for determining parity bits. The transmitter also may include a multiplexer for joining the parity bits with the data. A second encoder may be positioned after the multiplexer for implementing an error correcting code. A receiver of the communication system may include a decoder followed by an interleaver. When errors are detected in received data at the decoder, one or more processors of the receiver may be configured to correct portions of the received data and combine the corrected portions with the received data.

Abstract: The disclosure may provide for a communication method and system. A transmitter of the communication system may include an interleaver and a first encoder for determining parity bits. The transmitter also may include a multiplexer for joining the parity bits with the data. A second encoder may be positioned after the multiplexer for implementing an error correcting code. A receiver of the communication system may include a decoder followed by an interleaver. When errors are detected in received data at the decoder, one or more processors of the receiver may be configured to correct portions of the received data and combine the corrected portions with the received data.

Abstract: The technology relates to the design and placement of beacon transmission optics for free space optical communications (“FSOC”). One aspect of the disclosure provides an FSOC device with a beam steering mechanism, a beam column with a beam expander, an optical bus, and beacon transmission optics. The beacon transmission optics includes a prism that directs outgoing beacon beams into the beam column, and toward the beam steering mechanism. In one embodiment, the outgoing beacon beams do not need to travel through the beam expander of the beam column. As a result, backscatter is minimized and incoming or outgoing beams can be controlled with a single beam-steering mechanism.

Abstract: Aspects of the disclosure provide techniques for automatic repeat request (ARQ) in a free-space optical communication (FSOC) architecture. These techniques, including block-selective ARQ, adaptive retransmission delay, and random seed scrambling, can be used individually or in combination to combat problems involving frame loss or corruption. These techniques enable the system to rapidly recover by streamlining the retransmission process. For instance, block-selective ARQ acknowledges variable length blocks of frames in the return stream from the receiver to the transmitter. Adaptive retransmission delay allows the retransmission delay to grow in the absence of feedback by the receiver, up to some defined limit. And with random seed sampling, a scrambling sequence is incorporated to aid with frame syncing, which avoids the need for a line code. These aspects of the technology provide a robust communication process, and also reduce overhead costs associated with unnecessary retransmissions.

Abstract: A data rate at which data can be transmitted is adapted in real-time to power fluctuations. Bits of data to be sent by a transmitter are mapped to physical symbols, where a first modulation uses a first number of bits per pulse and a second modulation uses a second number of bits per pulse. Both modulations are sent, with one nested inside the other. A receiver decodes one or both bit streams, depending on a signal to noise ratio (SNR). In this regard, the data rate traces the received power, and higher data rates may be used despite periods of power fluctuations. This technique enables rapid, or even instantaneous, changes by using nested modulation. Moreover, a fast feedback mechanism is used to inform the transmitter when to change its modulation and to retransmit bits lost during an initial transmission.

Abstract: The disclosure may provide for a communication method and system. A transmitter of the communication system may include an interleaver and a first encoder for determining parity bits. The transmitter also may include a multiplexer for joining the parity bits with the data. A second encoder may be positioned after the multiplexer for implementing an error correcting code. A receiver of the communication system may include a decoder followed by an interleaver. When errors are detected in received data at the decoder, one or more processors of the receiver may be configured to correct portions of the received data and combine the corrected portions with the received data.

Abstract: Aspects of the disclosure provide techniques for automatic repeat request (ARQ) in a free-space optical communication (FSOC) architecture. These techniques, including block-selective ARQ, adaptive retransmission delay, and random seed scrambling, can be used individually or in combination to combat problems involving frame loss or corruption. These techniques enable the system to rapidly recover by streamlining the retransmission process. For instance, block-selective ARQ acknowledges variable length blocks of frames in the return stream from the receiver to the transmitter. Adaptive retransmission delay allows the retransmission delay to grow in the absence of feedback by the receiver, up to some defined limit. And with random seed sampling, a scrambling sequence is incorporated to aid with frame syncing, which avoids the need for a line code. These aspects of the technology provide a robust communication process, and also reduce overhead costs associated with unnecessary retransmissions.

Abstract: Aspects of the disclosure provide techniques for automatic repeat request (ARQ) in a free-space optical communication (FSOC) architecture. These techniques, including block-selective ARQ, adaptive retransmission delay, and random seed scrambling, can be used individually or in combination to combat problems involving frame loss or corruption. These techniques enable the system to rapidly recover by streamlining the retransmission process. For instance, block-selective ARQ acknowledges variable length blocks of frames in the return stream from the receiver to the transmitter. Adaptive retransmission delay allows the retransmission delay to grow in the absence of feedback by the receiver, up to some defined limit. And with random seed sampling, a scrambling sequence is incorporated to aid with frame syncing, which avoids the need for a line code. These aspects of the technology provide a robust communication process, and also reduce overhead costs associated with unnecessary retransmissions.

Abstract: A data rate at which data can be transmitted is adapted in real-time to power fluctuations. Bits of data to be sent by a transmitter are mapped to physical symbols, where a first modulation uses a first number of bits per pulse and a second modulation uses a second number of bits per pulse. Both modulations are sent, with one nested inside the other. A receiver decodes one or both bit streams, depending on a signal to noise ratio (SNR). In this regard, the data rate traces the received power, and higher data rates may be used despite periods of power fluctuations. This technique enables rapid, or even instantaneous, changes by using nested modulation. Moreover, a fast feedback mechanism is used to inform the transmitter when to change its modulation and to retransmit bits lost during an initial transmission.