Chromatic dispersion compensation is performed in one or more pluggable optical transceiver (POT) devices operating within an intensity-modulated direct-detection (IMDD) optical network. Compensation is performed within each POT using an electrical and/or optical chromatic dispersion module which are controlled by a set of parameters. A network computing device includes a computer processor and a host management interface for communicating with the POT. In the event of a link failure, the computer processor determines a second set of parameters to control the one or more dispersion compensation module(s) of the POT. The second set of parameters are different from a first set of parameters used to control the one or more compensation module(s) in the case of a first optical path. The computer processor causes the POT to use the second set of parameters in place of the first set of parameters.

Chromatic dispersion compensation is performed in one or more pluggable optical transceiver (POT) devices operating within an intensity-modulated direct-detection (IMDD) optical network. Compensation is performed within each POT using an electrical and/or optical chromatic dispersion module which are controlled by a set of parameters. A network computing device includes a computer processor and a host management interface for communicating with the POT. In the event of a link failure, the computer processor determines a second set of parameters to control the one or more dispersion compensation module(s) of the POT. The second set of parameters are different from a first set of parameters used to control the one or more compensation module(s) in the case of a first optical path. The computer processor causes the POT to use the second set of parameters in place of the first set of parameters.

An optical reception device includes a coefficient update section which optimizes a dispersion coefficient used in compensation of wavelength dispersion of a received signal obtained by receiving an optical signal according to a coherent detection method and a phase rotation amount used in compensation of a nonlinear optical effect of the received signal, and a transmission characteristic estimation section which estimates a transmission characteristic of a transmission line by using the optimized dispersion coefficient and the optimized phase rotation amount.

A computation unit uses an assumed chromatic dispersion amount to compensate for dispersion of a coherently received optical signal and performs arithmetic of a signal power of the optical signal that is dispersion compensated. The computation unit performs computation of an evaluation function when a signal power and a delayed signal power obtained by applying a predetermined delay to the signal power satisfy a threshold condition. The evaluation function is a function for evaluating whether the assumed chromatic dispersion amount is a chromatic dispersion amount of the optical signal using the difference between the signal power and the delayed signal power. The chromatic dispersion amount calculation unit calculates a chromatic dispersion amount of the optical signal based on the computation result of the evaluation function by the computation unit when each of a plurality of different assumed chromatic dispersion amounts is used.

An optical reception apparatus includes a wavelength dispersion compensation unit that performs wavelength dispersion compensation individually on reception signals that are obtained by receiving, by a coherent detecting scheme, an optical signal modulated in a subcarrier modulation scheme and by performing division on a subcarrier-by-subcarrier basis, and a plurality of delay compensation units that compensate for a delay between reception signals at different subcarriers among the reception signals at subcarriers obtained by the wavelength dispersion compensation.

The disclosed systems, structures, and methods are directed to a single-stage frequency-domain equalization (FDEQ) structure implemented on a processor, comprising a data preprocessing unit configured to concatenate received data samples in time-domain digital signals, transform the concatenated data samples in the time-domain digital signals to frequency-domain digital signals, and an adaptive equalizer comprising 2×2 multiple-input multiple output (MIMO) configured to compensate for non-time-varying fixed impairments and time-varying adaptive impairments in the frequency-domain digital signals.

Methods, systems, and apparatus, including computer programs encoded on computer storage media, for applying non-linearity to digital subcarriers. A receiver includes a detector circuit operable to receive a first optical signal over an optical link, the first optical signal carrying first data. The receiver includes a carrier recovery estimation circuit operable to generate compensated data by correcting errors in the first data. The receiver includes a non-linear coefficient estimation circuit operable to (i) receive the compensated data, and (ii) estimate one or more non-linear coefficients, wherein information indicative of the estimated non-linear coefficients is transmitted over an optical network, such that a second optical signal is transmitted based, at least in part, on the estimated non-linear coefficients, the second optical signal being received by the receiver.

The present disclosure relates to a digital filter arrangement (DFA) for compensating group velocity dispersion (GVD) in an optical transmission system (OTS) wherein the DFA is configured to receive a sequence of samples of a digital input signal in the time domain in the form of consecutive blocks of size L. The DFA is configured to generate M discrete Fourier transforms of a current overlap block of a size N greater than the size L and of M−1 delayed versions of the current overlap block. The DFA is configured to filter the entries of the generated M discrete Fourier transforms to generate an output discrete Fourier transform with N entries, wherein the compensation filter is implemented by a delay network and a linear combination algorithm.

Techniques are described for providing a hybrid compensation of chromatic dispersion in optical networks to reduce power consumption by coherent receivers. In some examples, a controller may receive a chromatic dispersion value of an optical signal from a coherent receiver integrated with a receiver optical network device. The controller may compare the chromatic dispersion value with a threshold. The controller may, in response to determining that the chromatic dispersion value satisfies the threshold, perform at least one of: configure a switch connected to a dispersion compensation module (DCM) with a state to provide access to the DCM to compensate the chromatic dispersion value of the optical signal, or adjust a phase response of a filter of a coherent transmitter to compensate the chromatic dispersion value of the optical signal.

A receiver convolutes each of a real component and an imaginary component of each polarization of a polarization-multiplexed reception signal with an impulse response for compensating for frequency characteristics of the receiver and a complex impulse response for wavelength dispersion compensation, and generates, as input signals, the convoluted real component and imaginary component of each polarization and phase conjugations thereof, for each polarization. The receiver generates, for each polarization, a first addition signal obtained by multiplying each of the real component and the imaginary component of each polarization by a complex impulse response, thereafter adding together the multiplied real component and imaginary component, and applying a phase rotation for frequency offset compensation to the added components, and a second addition signal obtained by multiplying each of the phase conjugation of the real component of and the phase conjugation of the imaginary component of each polarization by a complex impulse response, thereafter adding together the multiplied phase conjugations, and applying a phase rotation opposite to the phase rotation for frequency offset compensation to the added phase conjugations, and adds or subtracts a transmission data bias correction signal to or from a signal obtained by adding together the generated first addition signal and second addition signal.