Abstract: Methods and apparatus for interference cancelation in a radio frequency communications device are described. In various embodiments a signal to be transmitted in converted into an optical signal and processed using an optical filter assembly including one or more optical filters to generate an optical interference cancelation signal. The optical interference cancelation signal is converted into an analog radio frequency interference cancelation signal using an optical to electrical converter prior to the analog radio frequency interference cancelation signal being combined with a received signal to cancel interference, e.g., self interference. The optical filter assembly can include a large number of taps, e.g., 30, 50, 100 or more. Each tap may be implemented as a separate optical filter or series of optical filters. Delays and/or gain of the optical filters can be controlled dynamically based on channel estimates which may change due to changes in the environment and/or communications device position.

Abstract: Example embodiments of this application provide a method and an apparatus for transmitting a service flow based on FlexE. The method includes: sending, by a first network device, a first FlexE overhead frame to a second network device, where the first network device and the second network device transmit a service flow using a first FlexE group, and the first FlexE overhead frame includes FlexE group adjustment identification information and PHY information of a physical layer (PHY) included in a second FlexE group; receiving, by the first network device, a second FlexE overhead frame sent by the second network device, where the second FlexE overhead frame includes FlexE group adjustment acknowledgment identification information; adjusting, by the first network device, the first FlexE group to the second FlexE group; and sending, by the first network device, the service flow to the second network device based on the second FlexE group, to dynamically adjust a FlexE group.

Abstract: Systems and methods for predicting performance of a modulation system are provided. A neural network model is trained using performance information of a source system. The neural network model is modified with transferable knowledge about a target system to be evaluated. The neural network model is tuned using specific characteristics of the target system to create a source-based target model. The target system performance is evaluated using the source-based target model to predict system performance of the target system.

Abstract: A satellite signal relay system according to an embodiment of the inventive concept includes: a plurality of remote units configured to receive an analog satellite signal, to convert the analog satellite signal into a digital satellite signal, to generate a characteristic signal for the analog satellite signal, to generate a transmission frame based on the digital satellite signal and the characteristic signal, and to convert the transmission frame into an optical transmission frame; and a central unit configured to convert optical transmission frames received from the plurality of remote units into transmission frames through an optical transmission medium, respectively, to extract a digital satellite signal and a characteristic signal from each of the converted transmission frames, and to convert any one of the extracted digital satellite signals into an analog satellite signal based on the extracted characteristics signals.

Abstract: An apparatus and system, including a switch; and a set of tiles; wherein each of the set of tiles include a PIC die, a DSP die, a driver die, and a TIA die and methods thereto.

Abstract: A data-receiving circuit adapted to an electronic device is provided herein. The electronic device receives a power-saving signal to operate in a power-saving mode. The data-receiving circuit includes a first register, a second register, a decoder, a data register, and a control circuit. The first register is configured to store a target value. The second register is configured to store the length of the target value. The decoder captures control data and endpoint data from an IR signal. The data register is configured to store the control data. The control circuit empties out the data register according to the power-saving signal and the endpoint signal.

Abstract: A path computation engine, PCE, (100) for an optical communications network comprising a plurality of nodes and a plurality of links.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for clock synchronizing an optical system and multiple leaf systems. In some implementations, a method includes: first data is received from an optical system. The first data is detected using a local oscillator signal provided by a local oscillator laser. The first data is processed using a first sampling rate. A frequency of a clock signal supplied by a reference clock is adjusted based on the processed first data. Second data is transmitted to the optical system at a rate based on the clock signal.

Abstract: An optical communication system includes a transmitter and at least one receiver employing a feature of an outdoor environment, or includes a transmitter and a receiver in each of multiple transceivers employing a respective or shared feature of the outdoor environment. The transmitter includes a laser emitting a beam of laser pulses having a wavelength. The transmitter encodes data into the laser pulses in the beam, and transmits the beam of laser pulses through free space of the outdoor environment and then onto a feature of the outdoor environment. Each receiver includes a line filter blocking light not having the wavelength. The receiver decodes data from the light that passes through the line filter and includes a diffusion of the beam from the feature.

Abstract: Communications systems and methods of controlling the same include generating and processing a constant envelope phase-modulated optical signal, the systems including an optical source configured to provide a carrier waveform, an encoding module configured to encode the data as a plurality of symbol sequences, a mapping module configured to convert the plurality of symbol sequences to a plurality of phase state changes and a plurality of directions according to a path-dependent phase modulation scheme, and a phase modulator configured to modulate the carrier waveform with the plurality of phase state changes and directions to generate the constant envelope phase-modulated optical signal.

Abstract: Modules for optical time-domain reflectometry (OTDR) are connected via at least one fiber link of a fiber optic communication network. The modules can perform OTDR operations on the at least one fiber link. In addition, the modules can establish an inter-node communication channel between each other on the at least one fiber link. The channel allows the OTDR modules to synchronize their OTDR operations and to exchange information, such as OTDR traces, between each other.

Abstract: Embodiments of this application provide a method and an apparatus for obtaining optical distribution network (ODN) logical topology information, a device, and a storage medium. The method includes: obtaining identification information of each first ONU that is connected to a first passive optical network (PON) port and whose optical path changes and feature data of the first ONU in a first time window, where the feature data includes receive optical power and/or an alarm event; obtaining, based on the feature data of each first ONU, a feature vector corresponding to each first ONU; and performing cluster analysis on the feature vector corresponding to each first ONU, to obtain topology information corresponding to the first PON port. ONU topology information is obtained by analyzing an ONU feature.

Abstract: A digital receiver is configured to process a polarization multiplexed carrier from a communication network. The polarization multiplexed carrier includes a first polarization and a second polarization. The receiver includes a first lane for transporting a first input signal of the first polarization, a second lane for transporting a second input signal of the second polarization, a dynamic phase noise estimation unit disposed within the first lane and configured to determine a phase noise estimate of the first input signal, a first carrier phase recovery portion configured to remove carrier phase noise from the first polarization based on a combination of the first input signal and a function of the determined phase noise estimate, and a second carrier phase recovery portion configured to remove carrier phase noise from the second polarization based on a combination of the second input signal and the function of the determined phase noise estimate.

Abstract: Methods and apparatus for coherent transmitter calibration are provided that employ direct detection (DD) using one single photodetector (PD). The provided method and apparatus do not require hardware for coherent reception, or additional ADCs for quality control. An additional optical tone is added to a QAM optical signal that is outside the band of the QAM optical signal. The result of this is that after direct detection, there is a correlation between the real and imaginary parts, and the imaginary part can be recovered with a Hilbert transform. The estimated QAM optical signal obtained by direct detection is used to perform a transmitter factory calibration method to calibrate for one or more transmitter impairments and/or to perform in-line self-calibration.

Abstract: A method of configuring an optical link with an optimized spectral efficiency and bit rate is provided. The method includes obtaining, by a controller of an optical network, a baseline configuration that includes a traffic mode that uses a predetermined channel spacing of a plurality of channels in a frequency spectrum. The plurality of channels are used for transmitting optical signals on an optical link in the optical network. The method further includes selecting three contiguous channels that include a center channel and two adjacent channels and while maintaining a performance parameter above or equal to a threshold value, moving the adjacent channels closer to the center channel and varying at least one transmission parameter, thereby reducing a spacing of the center channel. As such, a spectral frequency map is generated in which the channel spacing is reduced and an optical link is configured based on the spectral frequency map.

Abstract: A method realizes synchronous playing of audio data from an audio source by two or more wireless speakers. The method includes receiving at each of the wireless speakers first audio data packets sent by the audio source and determining a respective first time point for the receiving of the first audio data packets; processing the first audio data packets at each of the wireless speakers to generate respective second audio data packets, the second audio data packets each including audio data to be played with a fixed data length; setting a delayed play time and obtaining a playing time point at each of the wireless speakers, the obtaining of the playing time point being based on the respective first time point and the respective delayed play time; and playing the second audio data packets at each of the wireless speakers at the respective playing time point.

Abstract: Communication of light signals and optical cables can be managed to mitigate error associated with using optical cables to communicate light signals. A communication management component (CMC) can embed respective timing synchronization pulses in respective lights signals having respective wavelengths. The light signals can be typical light signals or can be squeezed and twisted to generate a desired twisted light signal. The light signals can be transmitted via the optical cable to a receiver. A CMC, at the receiver end, can determine error associated with the transmission of the light signals via the optical cable and respective characteristics of the respective light signals, including respective arrival times of the respective timing synchronization pulses and respective light intensity or power levels of the respective light signals. From the respective characteristics, CMC can determine a compensation action to perform mitigate the error with regard to subsequent transmissions of light signals.

Abstract: A symbol-determining device according to an embodiment includes: a transmission line shortening unit that multiplies each symbol value of a symbol array that is part of an input signal by a tap gain of a linear digital filter and outputs a symbol array representing a sum of values acquired through the multiplication; a transmission line estimating unit that estimates a transfer function of a transmission line using an adaptive nonlinear digital filter on the basis of a symbol array representing a state of the transmission line; an addition comparison processing unit that calculates a minimum value of a distance function in a Viterbi algorithm on the basis of a metric that is calculated on the basis of the output of the transmission line shortening unit and the transfer function; and a path tracing-back determination unit that performs symbol determination by tracing back a trellis path in the Viterbi algorithm on the basis of the minimum value of the distance function.

Abstract: Quantum network nodes use light from a laser to stimulate emission of single photons. A detection station detects arrival of the photons from the quantum network nodes at a photon arrival detector. In time slots between single photon emissions, the quantum network node supply light from the laser to the detection station. The detection station measures a phase differences between light from a reference laser and the light received from different quantum network nodes in said time slots. The detection station has optical phase and/or frequency modulators between the optical inputs for light from the quantum network nodes and the photon arrival detector.

Abstract: A quantum communications system may include a transmitter node, a receiver node, and a quantum communications channel coupling the transmitter node and receiver node. The receiver node may be configured to arrange a received bit stream of optical pulses from the transmitter node into time bins, convert the optical pulses in the time bins into corresponding optical pulses in frequency bins, and detect respective optical pulse values from each of the frequency bins.