A data transmission method includes receiving, by an optical line terminal (OLT) from an optical network unit (ONU), uplink burst data that includes a synchronization data block and a payload, where the synchronization data block includes first synchronization data, wherein the first synchronization data includes a first preamble and an ONU identifier, and a first bandwidth occupied by the first frequency distribution of the first synchronization data is narrower than a second bandwidth occupied by the second frequency distribution of the payload, and obtaining, by the OLT from the first synchronization data, the ONU identifier.

An electronic device may include wireless circuitry clocked using an electro-optical phase-locked loop (OPLL) having primary and secondary lasers. A frequency-locked loop (FLL) path and a phase-locked loop (PLL) path may couple an output of the secondary laser to its input. A photodiode may generate a photodiode signal based on the laser output. A digital-to-time converter (DTC) may generate a reference signal. The FLL path may coarsely tune the secondary laser based on the photodiode signal until the secondary laser is frequency locked. Then, the PLL path may finely tune the secondary laser based on the reference signal and the photodiode signal until the phase of the secondary laser is locked to the primary laser. The photodiode signal may be subsampled on the PLL path. This may allow the OPLL to generate optical local oscillator signals with minimal jitter and phase noise.

An optical link channel auto-negotiation method and apparatus, a non-transitory computer-readable storage medium are disclosed. The optical link channel auto-negotiation method may include at least one of the following: configuring a receiving rate, determining whether a receive clock recovered from received data by a physical layer (PHY) module is locked, and in response to determining that the receive clock recovered from the received data by the PHY module is locked, determining that the receiving rate is configured correctly; configuring a first predetermined parameter in response to determining that the receiving rate is configured correctly, determining whether code block data of the PHY module is in a synchronized state, and in response to determining that the code block data of the PHY module is in a synchronized state, determining that the first predetermined parameter is configured correctly.

Systems, methods and apparatus are provided for a reusable, client-server based ecosystem designed to support content-aware, LiFi-powered transfer of large-scale, semi-structured data files. Containerized client-side applications may include a LiFi communication engine (LCE), a job control engine (JCE), and an execution hub that is configured to interface with the JCE, the LCE, job stakeholders and downstream applications. A central server may include a server-side LCE configured for two-way communication with the client-side LCE. Each LCE may be configured to cluster semi-structured data into data packets, broadcast data packets using an LED array, receive data packets using an array of photoreceptors and synchronize received data packets.

An interface or communications system for a neural probe, the interface or communications system comprising at least one probe interface, an optical communications interface and a processing system. The at least one probe interface is configured to interface with at least one neural probe so as to receive data collected by the probe. The processing system is configured to process the data from the at least one probe interface and provide the processed data to the optical communications interface. The optical communications interface is configured to communicate the processed data to a remote device, e.g. using optical wireless communications. The optical communications interface has the large bandwidth available that will allow the scaling up of recording sites from the neural probe without resulting in undue size, weight and/or power consumption.

Techniques (e.g., method, apparatuses, etc.) for permitting communications, e.g., optical communications are described. In one example, a first communication apparatus may send a bit allocation table, BAT, message, to a second communication apparatus. The BAT update information has a BAT update information signalling update information for updating a BAT which is signalled to be updated. The BAT update information groups information into different groups of subcarriers, wherein the BAT update information has, for each group of subcarriers, information indicating the number of carriers in the group.

Joint estimation of the framer index and the frequency offset in an optical communication system are described among various other features. A transmitter can transmit data frames using pilot and framer symbols. A receiver can estimate the framer index and frequency offset using the pilot and framer symbols, and identify the beginning of a header portion of a data frame. By identifying the beginning of the header portion of a data frame, the receiver can synchronize, with less error, the data transmitted by the transmitter and the data it received. To further improve the framer index estimation, a lock indicator signal can be generated to signal to other receiver components that the estimated framer indices are reliable. The receiver can determine frequency offset and additional framer index estimations with increased reliability when performed after the lock indicator signal is generated.

Provided are methods for optical communication, comprising: generating a phase difference signal with heterodyne or homodyne phase-locked-loop (PLL) from between an optical input signal and a local laser source; controlling the local laser source with the phase difference signal; demodulating the optical input signal using the local laser source as a carrier signal to generate a baseband output signal; and controlling the heterodyne or homodyne PLL and the demodulation with an electrical oscillator signal. Also provided are related methods.

An optical module for use in an optical system is disclosed, the optical module implementing Precision Time Protocol (PTP) clock functionality therein. The optical module includes an electrical interface with the optical system; circuitry connected to the electrical interface and configured to implement a plurality of functions of functionality; an optical interface connected to the circuitry; and timing circuitry connected to the electrical interface and one or more of the plurality of functions, wherein the timing circuitry is configured to implement the PTP clock functionality.

A frame synchronization system (1) according to this invention includes a frame signal generation circuit (20) configured to generate a frame signal including a plurality of first frame signals each including a first frame synchronization signal and a first payload signal, wherein the first frame synchronization signal is formed from at least one symbol and is set with an average amplitude lower than an average amplitude of the first payload signal, and a frame synchronization circuit (60) configured to receive the frame signal via an optical transmission path (70), and detect the first frame synchronization signal from a received signal, wherein the received signal is divided into frames having a symbol length of the first frame signal, coordinate values, on an IQ plane, of the signals at identical symbol positions of the plurality of divided frames are added over the plurality of frames, and a symbol specified by magnitude comparison in the frame based on an addition result is determined as the first frame synchronization signal. Even if a transmission rate is high, it is possible to decrease the probability of erroneous synchronization, thereby shortening the time until frame synchronization is established.