The present specification provides a method, performed by a device, for transmitting information about a pencil beam timing offset in a wireless optical communication system, in which a reference synchronization time is obtained, wherein the reference synchronization time is obtained on the basis of a cell-reference synchronization signal (C-RSS) received from another device, a peak energy time is obtained, the pencil beam timing offset is obtained on the basis of the reference synchronization time and the peak energy time, and information about the pencil beam timing offset is transmitted to the other device.

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 then process data received from the transmitter in a manner synchronous to the manner in which the data was transmitted by the transmitter.

An optical communication device including a GPS receiver receiving and outputting a GPS signal from a satellite; a main controller configured to generate and output synchronization data based on the GPS signal; and an optical transceiver configured to generate an optical signal by superposing input payload data and the synchronization data, and to output the optical signal, wherein a first communication channel corresponding to the payload data and a second communication channel corresponding to the synchronization data are different communication channels. According to embodiments, GPS information for synchronization together with payload data, which is information to be transmitted, may be efficiently transmitted between optical communication devices located in remote locations without separate wavelength allocation and connection of an optical cable, by using an auxiliary management and control channel (AMCC).

Provided are a method and a device for implementing timeslot synchronization. The method includes: a master node performing timeslot synchronization training of an OBTN according to a timeslot length of the OBTN. By adopting the solution provided by the embodiments of the present disclosure, an FDL does not need to be considered in node design, the node design is simplified, the time precision of synchronization is improved and no loss is caused to optical efficiency.

A decoding device for an absolute positioning code is provided. The decoding device includes a linear feedback shift register (LFSR), a lookup table (LUT) circuit, a counter circuit, and a computation circuit. The LFSR includes n registers, for loading the absolute positioning code with a first frequency. The LFSR performs shifting operation according to a clock signal having a second frequency greater than or equal to the first frequency. The LUT circuit outputs a lookup result and a valid flag according to values stored in the n registers. The lookup result has k different data, k≦(2.sup.n−1). The counter circuit resets according to the valid flag, and performs counting operation according to the clock signal to generate a counting result. The computation circuit performs calculation according to the lookup result and the counting result to generate a decoding result when the valid flag indicates valid.

The present disclosure is directed to a system and method of distributing time information to enable synchronization in an authenticated manner via a quantum channel. A source device may transmit a timing signal, T on a communication channel from the source device to a receiver device. The timing signal T may be include a time or times stored in memory or calculated using a previously agreed upon formula. The method may include transmitting a quantum system Q from the source device to the receiver device. The quantum system may be prepared in a randomly chosen state and may be measured by the receiver device in a randomly chosen measurement basis.

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.

An heterodyne apparatus and method for measuring performance parameters of a coherent optical receiver at RF frequencies is disclosed. Two coherent lights are launched into signal and LO ports of the receiver with an optical frequency offset f. One of the lights is modulated in amplitude at two phase-locked modulation frequencies F.sub.1 and F.sub.2. COR performance parameters are determined by comparing two frequency components of the COR output. The group delay variation (GDV) information is obtained by comparing phases of two time-domain traces corresponding to frequency components of the COR output signal at the two modulation frequencies shifted by the optical frequency offset f.

A device and a method for synchronizing entanglement sources with optical pump in a quantum communication network are disclosed. The device includes a pulsed optical source allowing emission of telecom wavelength optical clock pulses distributed in parallel to the entanglement sources to ensure synchronization of the entanglement sources; and for each of the entanglement sources, a frequency conversion device, allowing frequency conversion of the distributed telecom wavelength optical clock pulses to a wavelength adapted to optically pump the entanglement source. The method includes emitting and distributing in parallel, to the entanglement sources, telecom wavelength optical clock pulses; and locally, at each of the entanglement sources, frequency converting the telecom wavelength optical clock pulses to a wavelength adapted to optically pump the entanglement source.

Systems, apparatus, and methods for packetized clocks may include a packet interface to carry the rate of a client to a sigma-delta modulator that generates a clock at the required rate inside the chip itself there by removing the need for off-chip analog PLLs. The packetized clock may include a packet interface that receives a flow credit packet that includes a plurality of flow credit counts, one flow credit count for each data flow, and forwards a flow credit count for each data flow to one of a plurality of clock generators to generate a new clock signal for each data flow.