Abstract: Provided are a staircase code decoding method and a staircase code decoding apparatus. The method includes: step 1, obtaining the length L of a sliding window, and continuously obtaining, starting from a P-th subcode block, L subcode blocks as first to-be-decoded subcode blocks in the sliding window; step 2, dividing the first to-be-decoded subcode blocks into a plurality of first to-be-decoded groups, respectively decoding the plurality of to-be-decoded groups to be decoded, and updating the plurality of first to-be-decoded groups according to a decoding result to obtain first updated subcode blocks; step 3, sliding the sliding window forwards by a length of N subcode blocks; step 4, dividing second to-be-decoded subcode blocks into a plurality of second to-be-decoded groups, decoding the plurality of second to-be-decoded groups, obtaining second updated subcode blocks, and outputting first M subcode blocks among the second updated subcode blocks; and step 5, sliding the sliding window backwards by S.

Abstract: A system for visible light communication having a portable device with a visible light source operated to emit optical signals as light pulses representative of data, and a warning device having one or more sources providing one or more of visible and/or audible warning signals. The warning device has a controller which detects the data using electrical signals received from a light sensor representative of the light pulses. Responsive to at least a portion of the detected data, the controller operates one or more sources of the warning device. The detected data includes one or more programming options, such as patterns, for operating the one or more sources of the warning device. The portable device may be a smartphone or tablet having a built-in flash providing the visible light source, where programming options are selectable via a user interface along the portable device.

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 transmitter node may cooperate with the quantum communications channel defining at least one Talbot effect image position along the quantum communications channel. The receiver node may use located along the quantum communications channel at the at least one Talbot effect image position.

Abstract: An optical communication system includes a first communication device configured to transmit optical signals, and a second communication device configured to receive the optical signals. The first transmission device includes encoding circuit that configured to assign, to a plurality of bit strings, symbols each corresponding to a value of every one of the plurality of bit strings, the symbols being among a plurality of symbols in a constellation of a multi-level modulation scheme, convert values of bit strings, generate the second error correction code from a second bit string among the plurality of bit strings in every one of a plurality of periods, delay the first error correction code, and delay the second error correction code, wherein the encoding circuit uses the delayed first error correction code and the delayed second error correction code to convert a value of the second bit string.

Abstract: A device for controlling upstream transmission of bursts from optical network units (ONUs) to an optical line termination (OLT) in a passive optical network (PON), wherein the upstream transmission is organized in time intervals that form part of an upstream timeframe, includes obtain respective optical power levels received at the OLT for the ONUs; obtain respective extinction ratios at the OLT for the ONUs; obtain respective transmission wavelengths for the ONUs; distinguish pairable ONUs and non-pairable ONUs at least based on the wavelengths; pair the pairable ONUs based on the optical power levels and/or the extinction ratios to generating one or plural subsets of paired ONUs; allow paired ONUs that belong to a same subset to simultaneously transmit bursts within a time interval.

Abstract: A distributed fiber optic communication network for controlling a gas turbine engine includes a computation module and an input/output (I/O) module. The computation module and the I/O module are connected via the communication network. The communication network comprises multi-mode fiber optic cables, wherein data is transferred thereon on multiple frequency bands. The frequency bands range from about 300 nm to about 1550 nm. A method of frequency hopping is provided in which communication band instructions are stored locally on nodes of the communication network and may include communication band instructions transmitted to nodes of the communication network on a dedicated band.

Abstract: A HDMI apparatus is provided. The HDMI apparatus includes a first audio/video transceiver (A/V transceiver) configured to transmit an optical A/V signal to a second A/V transceiver; and a first sideband transceiver configured to drive a first laser diode to transmit a first optical sideband signal including a first control information or a first power information; wherein the first control information or the first power information is converted by a first Serializer/Deserializer (SERDES).

Abstract: Techniques for data transmission include a geostationary earth orbiting satellite that includes a first optical communication system configured to receive forward-direction user data via a forward optical link between the satellite and a stratospheric high-altitude communication device, and a first radio frequency (RF) communication system configured to transmit, via a plurality of RF spot beams, the forward-direction user data. The stratospheric high-altitude communication device includes a second RF communication system configured to receive the forward-direction user data via a plurality of concurrent forward RF feeder links, and a second optical communication system configured to transmit to the satellite, via the forward optical link, the forward-direction user data received via the plurality of forward RF feeder links.

Abstract: The present disclosure is directed to systems and methods for calculating a modal time delay and a modal bandwidth. For example, a method may include: transmitting an intensity-modulated light through a mode conditioner to generate a mode-conditioned intensity-modulated light; transmitting the mode-conditioned intensity-modulated light through an optical fiber under test (FUT) to excite a plurality of modes of the optical FUT; converting the mode-conditioned intensity-modulated light transmitted through the optical FUT into an electrical signal; measuring, based on the electrical signal, a transfer function or a complex transfer function of the optical FUT based on at least on one pair of the plurality of modes; calculating a modal delay time of the optical FUT based on the transfer function or the complex transfer function; and calculating a modal bandwidth of the optical FUT based on the modal delay time, the modal bandwidth being calculated for any given launch conditions of the plurality of modes.

Abstract: An optical transmitter for probabilistic shaping and symbol rate optimization includes one or more matcher elements, each configured to assign respective probabilities to symbols represented in received binary data dependent on a target probability distribution and to output a respective shaped bit sequence. The optical transmitter further includes a single systematic error correction encoder configured to add parity bits collectively across the shaped bit sequences and to output a combined shaped bit sequence including data representing the shaped bit sequences and the added parity bits. The optical transmitter also includes multiple mapping elements, each configured to generate a respective codeword for each symbol represented in a portion of the combined shaped bit sequence, a serial-to-parallel converter to provide portions of the combined shaped bit sequence to the mapping elements, and a multiplexer to combine binary data representing the codewords for transmission using subcarrier multiplexing.

Abstract: An example system for multi-wavelength optical signal splitting is disclosed. The example disclosed herein comprises a first splitter, a second splitter, and a modulator. The system receives a multi-wavelength optical signal and an electrical signal, wherein the multi-wavelength optical signal comprises a plurality of optical wavelengths and has a power level. The first splitter is to split the plurality of optical wavelengths into a plurality of optical wavelength groups. The second splitter is to split the multi-wavelength optical signal or the plurality of optical wavelength groups into a plurality of lower power signal groups. The modulator is to encode the electrical signal into the plurality of optical wavelength groups, the plurality of lower power signal groups, or a combination thereof.

Abstract: A system for transferring data between a rotating element and a fixed element by wireless optical communication, including a plurality of rotating optical transmitters distributed in a ring around the turning element and solidly attached to the rotating element, and at least one fixed optical receiver mounted on and solidly attached to the fixed element, arranged at the same height as the plurality of rotating optical transmitters in which the rotating optical transmitters simultaneously transmit a same optical signal, independently of the angular position of the rotating element and are sufficiently numerous such that regardless of the angular position of the rotating element, the fixed optical receiver receives an optical signal.

Abstract: An information transmitter apparatus for use in an information transmission system is provided, where the information transmission system includes the information transmitter apparatus and an information receiver apparatus. The information transmitter apparatus transmits a surface-shaped visible light signal using a light source, where the visible light signal is modulated according to a modulated signal modulated using a plurality of respective-order carriers different from each other, and the respective-order carriers has a fundamental frequency and multiple frequencies of a frame output signal of a video camera of rolling shutter system provided in an information receiver apparatus. The information receiver apparatus receives the visible light signal using the video camera.

Abstract: The present invention relates to an all-in-one converter using a low-speed optical module on a high-speed switch. The present invention relates to the field of optical modules in optical communications. It provides a solution of using a 25G optical module on a 100G switch, and simultaneously enabling a 10G optical module to be used on a 40G switch. A first electrical interface of the converter is connected with a 100G/40G switch, which meets the requirements of SFF-8636 protocol and realizes the bidirectional transmission of signals from the switch to the converter. A second electrical interface of the converter is connected with the optical module, which realizes the module's bidirectional transmission from the converter to the optical module. There is a signal conversion circuit inside the converter, which makes the signals of the two electrical interfaces meet the requirements of their respective protocols.

Abstract: A Rydberg atom mixer determines a phase of modulated carrier radiation and includes: a reference radiofrequency source for reference radiofrequency radiation; a modulated carrier source for modulated carrier radiation; a vapor cell to contain gas atoms and that receives reference radiofrequency radiation and modulated carrier radiation, such that the gas atoms produce modulated light modulated; and a transmission detector that receives the modulated light from the vapor cell and produces a transmission signal from the transmission detector for determination of a phase of the modulated carrier radiation, wherein the Rydberg atom mixer mixes the reference radiofrequency radiation and the modulated carrier radiation by the gas atoms in a Rydberg electronic state to produce the intermediate frequency IF that corresponds directly to the phase of the modulated carrier radiation.

Abstract: A signal detection circuit has a first differential amplifier including a first input coupled for receiving a data signal, and a second input coupled for receiving a threshold signal. A current steering circuit is coupled to an output of the first differential amplifier to establish a threshold for the first differential amplifier. A latch has an input coupled to the output of the first differential amplifier for latching a signal detect. A second amplifier has an input coupled to the output of the first differential amplifier and an output coupled to the input of the latch. A third amplifier has an input coupled to the output of the first differential amplifier and an output providing the data signal. The current steering circuit can be disabled which removes the need for the third amplifier as the data signal path is through second amplifier.

Abstract: A multimode combiner or coupler (MMC) may combine the inputs into a larger core multimode fiber. The multimode combiner may be combined with a re-transmitting laser for detecting and re-transmitting signals. Thus, the multi-mode combiner may detect and combine input signals, and then retransmit the detected, combined signal. The detection can be implemented with multiple single mode fibers to small single mode detectors or a multi-mode coupler with a larger multi-mode detectors. In embodiments of the MMC, a bi-directional optical splitter/combiner includes a transmitter for re-transmitting an RF signal received at a receiver, a first wave division multiplexer (WDM) combiner combining the output of the first transmitter in an upstream direction to a downstream signal in a downstream direction, and a second WDM combiner combining split downstream signals in the downstream direction with upstream signals received via at least two optical fiber inputs.

Abstract: This disclosure describes digitally generating sub-carriers (SCs) to provide isolation and dynamic allocation of bandwidth between uplink and downlink traffic between transceivers that are communicatively coupled via a bidirectional link including one or more segments of optical fiber. Separate uplink and downlink communication channels may be created using digitally generated SCs and using the same transmitter laser. In some implementations, one or more of the nodes include a transceiver having at least one laser and one digital signal processing (DSP) operable for digitally generating at least two SCs and detecting at least two SCs. The transceiver can transmit selected SCs, and can receive other SCs. Accordingly, the transceiver can facilitate bidirectional communication, for example, over a single optical fiber link. In some instances, techniques can facilitate dynamic bandwidth assignment by facilitating adding or blocking of optical subcarriers from transmission in an uplink or downlink direction.

Abstract: Short-term optical recovery systems and methods in coherent optical receivers minimize recovery time for fault scenarios and signal reacquisition while maintaining robust signal acquisition. The short-term optical recovery systems and methods include special techniques and algorithms to minimize recovery time, making coherent systems similar in time as conventional direct detection recovery. The short-term optical recovery systems and methods include an expedited acquisition engine that includes a reference clock recovery, a compensator to remove chromatic dispersion, a burst framer, and a compensator to remove polarization dispersion. Importantly, the expedited acquisition engine uses a memory oriented architecture to allow some properties of the acquisition engine to be stored during initial acquisition and, hence, later on be deployed in any fault scenario to expedite further recovery of a signal.

Abstract: A virtual subscriber line terminal station device includes a software component including software to be added in accordance with a service requirement; and hardware having general-purpose functions; wherein the hardware includes a communication unit that receives a bandwidth allocation request transmitted by a subscriber line termination device; and the software component includes a bandwidth allocation component. The bandwidth allocation component has an individual unit that, based on an algorithm for allocating bands, computes a bandwidth to be allocated to the subscriber line termination device that transmitted the bandwidth allocation request; a common unit that, in accordance with the bandwidth allocated by the individual unit, allocates the bandwidth to the subscriber line termination device; and an interface between the individual unit and the common unit. The common unit converts the bandwidth allocation request received by the communication unit to a format that can be used by the individual unit.