Abstract: In a method, a network device receives a combined optical signal, where the combined optical signal is obtained by coupling optical signals sent by a plurality of communication nodes. If the network device is not a master node, the network device detects whether a master label exists in the combined optical signal, where the master label indicates the master node. If it is detected that a first master label exists in the combined optical signal, where the first master label indicates a first master node, the network device synchronizes a local clock frequency with a clock frequency of the first master node.

Abstract: An optical receiver obtains a to-be-processed signal block; the optical receiver determines a prediction signal block corresponding to the to-be-processed signal block; the optical receiver determines a noise compensation coefficient of the to-be-processed signal block based on the to-be-processed signal block and the prediction signal block; and the optical receiver performs noise compensation on the to-be-processed signal block based on the noise compensation coefficient.

Abstract: An optical coupler, a communication method, and a communication system are provided. The communication system includes N transmitters, M receivers, and an optical coupler, where both N and M are positive integers greater than 1. Each of the N transmitters is configured to send one first optical signal to the optical coupler. The optical coupler is configured to couple N first optical signals sent by the N transmitters into one second optical signal and to broadcast the second optical signal to the M receivers. Each of the M receivers is configured to receive the second optical signal sent by the optical coupler and to demodulate the second optical signal.

Abstract: An optical communication apparatus may include a frequency locking module and a signal light generation module. The frequency locking module is configured to: generate a target wavelength control signal based on an optical frequency difference indication signal and send the target wavelength control signal to the signal light generation module. The frequency locking module is further configured to generate a target electrical modulation signal based on a target optical frequency difference, a target electrical frequency difference, and to-be-transmitted bit information that are determined by using the optical frequency difference indication signal. The signal light generation module is configured to: generate third signal light based on the target wavelength control signal and the target electrical modulation signal and send the third signal light to a second optical communication apparatus.

Abstract: A decoding method performed by a receive end device is disclosed. The decoding method includes: receiving a first bit signal; performing level-M forward error correction (FEC) decoding on the first bit signal to obtain a second bit signal, where M is a positive integer greater than zero; checking the second bit signal to obtain a first check result; performing level-(M+1) FEC decoding on the second bit signal based on the first check result to obtain a third bit signal; and, upon determining that M+1 reaches a first preset threshold, performing data processing on the third bit signal to obtain a fourth bit signal, where the fourth bit signal is used by the receive end device to obtain service data transmitted by a transmit end device.

Abstract: The present disclosure relates to modulation methods. One example method includes performing distribution matching (DM) encoding on N1 first bits to obtain N2 first symbols, determining N4 to-be-phase-modulated symbols whose signal powers are equal to a preset signal power from the N2 first symbols, performing phase modulation on the N4 to-be-phase-modulated symbols based on N3 second bits to obtain N4 second symbols, performing binary labeling (BL) encoding on the N4 second symbols and N2-N4 first symbols to obtain N5 BL encoded output bits, performing forward error correction (FEC) encoding on the N5 BL encoded output bits to obtain N6 FEC redundant bits, and performing quadrature amplitude modulation (QAM) mapping based on the N6 FEC redundant bits and the N5 BL encoded output bits to obtain N2 target QAM signals.

Abstract: An optical receiver obtains a to-be-processed signal block; the optical receiver determines a prediction signal block corresponding to the to-be-processed signal block; the optical receiver determines a noise compensation coefficient of the to-be-processed signal block based on the to-be-processed signal block and the prediction signal block; and the optical receiver performs noise compensation on the to-be-processed signal block based on the noise compensation coefficient.

Abstract: The present disclosure relates to modulation methods. One example method includes performing distribution matching (DM) encoding on N1 first bits to obtain N2 first symbols, determining N4 to-be-phase-modulated symbols whose signal powers are equal to a preset signal power from the N2 first symbols, performing phase modulation on the N4 to-be-phase-modulated symbols based on N3 second bits to obtain N4 second symbols, performing binary labeling (BL) encoding on the N4 second symbols and N2-N4 first symbols to obtain N5 BL encoded output bits, performing forward error correction (FEC) encoding on the N5 BL encoded output bits to obtain N6 FEC redundant bits, and performing quadrature amplitude modulation (QAM) mapping based on the N6 FEC redundant bits and the N5 BL encoded output bits to obtain N2 target QAM signals.

Abstract: A decoding method performed by a receive end device is disclosed. The decoding method includes: receiving a first bit signal; performing level-M forward error correction (FEC) decoding on the first bit signal to obtain a second bit signal, where M is a positive integer greater than zero; checking the second bit signal to obtain a first check result; performing level-(M+1) FEC decoding on the second bit signal based on the first check result to obtain a third bit signal; and, upon determining that M+1 reaches a first preset threshold, performing data processing on the third bit signal to obtain a fourth bit signal, where the fourth bit signal is used by the receive end device to obtain service data transmitted by a transmit end device.

Abstract: An optical transmitter, an optical receiver, and an optical transmission method are disclosed. The optical transmitter includes an optical signal generator, N spreaders, N pairs of data modulators, and a combiner, where the optical signal generator generates N optical carriers; an ith spreader spreads an ith optical carrier, to obtain a spread optical signal having two subcarriers; splits the spread optical signal into a first optical signal and a second optical signal; and delays the second optical signal to obtain a third optical signal; an ith pair of data modulators modulate the first optical signal and the third optical signal to obtain a pair of modulated optical signals, transmit the pair of modulated optical signals to the combiner, where the pair of modulated optical signals reaching the combiner differ by 1/(4 fsi) in time domain; and the combiner combines, into one optical signal, N pairs of modulated optical signals.

Abstract: A receiver in the present disclosure includes: a first input end, N first output ends, N baseband signal recovery modules, and a multiple-input multiple-output equalization module. Each baseband signal recovery module includes two second output ends; one second output end of each baseband signal recovery module is configured to output a baseband signal; and the other second output end is configured to output data enabling control information. The multiple-input multiple-output equalization module is configured to: control, based on N pieces of data enabling control information, a time sequence of N baseband signals entering the multiple-input multiple-output equalization module for equalization filtering processing, and perform equalization filtering processing on the N baseband signals by using N transmitters as references to obtain recovered data of the N transmitters. According to the embodiments of the present disclosure, asynchronous multi-transmitter data is received.

Abstract: According to a signal transmitting method, a signal receiving method, and a related device and system, a generated single-wavelength optical carrier may be split into N subcarriers with a same wavelength by using a splitting device, corresponding data modulation and corresponding amplitude spread spectrum modulation are performed on the N subcarriers by using N spreading codes and N low-speed data signals obtained by deserializing a received high-speed data signal, to obtain N spread spectrum modulation signals, and the N spread spectrum modulation signals are combined and output. A multicarrier generation apparatus or the like having a relatively complex structure does not need to be used for optical carrier splitting, and spectrum spreading does not need to be performed in a phase modulation manner in which a plurality of delay units or controllable phase units are required.

Abstract: Embodiments described and shown provide a signal transmission method, a signal receiving method, a related device, and a system. The signal transmission method includes: generating a single-wavelength optical carrier; splitting the single-wavelength optical carrier into N subcarriers having a same wavelength; generating a spreading code corresponding to each of the subcarriers to obtain N spreading codes, where a bandwidth of each of the spreading codes is less than or equal to a preset threshold; deserializing a to-be-transmitted data signal into N sub-data signals; modulating the N subcarriers based on the N sub-data signals and the N spreading codes, to obtain N modulation signals; and combining the N modulation signals into one combined signal, and outputting the combined signal.

Abstract: Embodiments of this application provide a data transmission method, a terminal device, and a network side device. Encoding, by a terminal device, a first identifier by using a first code word which is selected from at least one code word by the terminal device; sending, by the terminal device, the encoded first identifier to a network side device; receiving, by the terminal device, a second identifier sent by the network side device; decoding, by the terminal device, the second identifier by using the first code word; when the decoded second identifier is the same as the first identifier, encoding, by the terminal device, subsequent data by using the first code word; and sending, by the terminal device, the encoded subsequent data to the network side device.

Abstract: An optical transmitter, an optical receiver, and an optical transmission method are disclosed. The optical transmitter includes an optical signal generator, N spreaders, N pairs of data modulators, and a combiner, where the optical signal generator generates N optical carriers; an ith spreader spreads an ith optical carrier, to obtain a spread optical signal having two subcarriers; splits the spread optical signal into a first optical signal and a second optical signal; and delays the second optical signal to obtain a third optical signal; an ith pair of data modulators modulate the first optical signal and the third optical signal to obtain a pair of modulated optical signals, transmit the pair of modulated optical signals to the combiner, where the pair of modulated optical signals reaching the combiner differ by 1/(4 fsi) in time domain; and the combiner combines, into one optical signal, N pairs of modulated optical signals.

Abstract: A signal processing method is provided. Under the method, a first digital signal can be obtained by an optical transmitter. The first digital signal is a one-dimensional bipolar digital signal. A spectral compression and filtering can be performed by the optical transmitter on the first digital signal to generate a second digital signal. A frequency shift can be performed by the optical transmitter on the second digital signal such that a center location of a spectrum of the frequency-shifted second digital signal is at a frequency of 0.

Abstract: Embodiments of the present invention provide a receiver and a data receiving method. The receiver includes: two first input ends, configured to receive a digital signal of an X-polarization state and a digital signal of a Y-polarization state; a despreading module, configured to despread the digital signal of the X-polarization state and the digital signal of the Y-polarization state based on N delay values and spreading codes of N transmitters, to obtain N first baseband signals and N second baseband signals; and a multiple-input multiple-output equalization module, configured to perform equalization filtering processing on the N first baseband signals and the N second baseband signals, to obtain recovered data of the first polarization states and recovered data of the second polarization states of the N transmitters. In the embodiments of the present invention, the coherent CDMA multipoint-to-point data transmission in an optical communications system is implemented.

Abstract: Embodiments described and shown provide a signal transmission method, a signal receiving method, a related device, and a system. The signal transmission method includes: generating a single-wavelength optical carrier; splitting the single-wavelength optical carrier into N subcarriers having a same wavelength; generating a spreading code corresponding to each of the subcarriers to obtain N spreading codes, where a bandwidth of each of the spreading codes is less than or equal to a preset threshold; deserializing a to-be-transmitted data signal into N sub-data signals; modulating the N subcarriers based on the N sub-data signals and the N spreading codes, to obtain N modulation signals; and combining the N modulation signals into one combined signal, and outputting the combined signal.

Abstract: According to a signal transmitting method, a signal receiving method, and a related device and system, a generated single-wavelength optical carrier may be split into N subcarriers with a same wavelength by using a splitting device, corresponding data modulation and corresponding amplitude spread spectrum modulation are performed on the N subcarriers by using N spreading codes and N low-speed data signals obtained by deserializing a received high-speed data signal, to obtain N spread spectrum modulation signals, and the N spread spectrum modulation signals are combined and output. A multicarrier generation apparatus or the like having a relatively complex structure does not need to be used for optical carrier splitting, and spectrum spreading does not need to be performed in a phase modulation manner in which a plurality of delay units or controllable phase units are required.