Abstract: A method, system and apparatus for optimizing parameters between two optical coherent transceivers connected via an optical link, including determining performance of a second optical receiver; wherein the second optical transceiver uses a set of parameters; and inputting information into a side channel communication between a first optical transceiver and the second optical transceiver to update the set of parameters for the second transceiver.

Abstract: A method, system and apparatus for optimizing parameters between two optical coherent transceivers connected via an optical link, including determining performance of a second optical receiver; wherein the second optical transceiver uses a set of parameters; and inputting information into a side channel communication between a first optical transceiver and the second optical transceiver to update the set of parameters for the second transceiver.

Abstract: A method, system and apparatus for optimizing parameters between two optical coherent transceivers connected via an optical link, including determining performance of a second optical receiver; wherein the second optical transceiver uses a set of parameters; and inputting information into a side channel communication between a first optical transceiver and the second optical transceiver to update the set of parameters for the second transceiver.

Abstract: A method, system, and apparatus for calculating coefficients for inputs and corresponding output sequences for a pulse-position modulation encoder using a stored structure; wherein the structure is a subset of the values of Pascal's Triangle.

Abstract: A method, system and apparatus for optimizing parameters between two optical coherent transceivers connected via an optical link, including determining performance of a second optical receiver; wherein the second optical transceiver uses a set of parameters; and inputting information into a side channel communication between a first optical transceiver and the second optical transceiver to update the set of parameters for the second transceiver.

Abstract: A method, system, and apparatus for encoding a data for transmission across a communication link, the comprising encoding the data into a constellation; wherein the constellation is of a power 2n; wherein n is an odd number; wherein encoding the constellation creates outer constellation points forming a square at an edge of the constellation.

Abstract: An optical receiver includes an equalizer to generate a plurality of equalization coefficients corresponding to a plurality of frequencies of an optical signal received by the optical receiver. The equalizer zeroes out a first subset of the equalization coefficients corresponding to a first subset of the plurality of frequency components and applies a second subset of non-zero equalization coefficients to the first signal. The optical receiver may also include a chromatic dispersion compensator to generate inverse chromatic dispersion coefficients corresponding to the plurality of frequency components, and to zero out a first subset of the inverse chromatic dispersion coefficients corresponding to the first subset of the plurality of frequency components and further to apply a second subset of non-zero inverse chromatic dispersion coefficients to a second optical signal.

Abstract: An optical receiver includes an equalizer to generate a plurality of equalization coefficients corresponding to a plurality of frequencies of an optical signal received by the optical receiver. The equalizer zeroes out a first subset of the equalization coefficients corresponding to a first subset of the plurality of frequency components and applies a second subset of non-zero equalization coefficients to the first signal. The optical receiver may also include a chromatic dispersion compensator to generate inverse chromatic dispersion coefficients corresponding to the plurality of frequency components, and to zero out a first subset of the inverse chromatic dispersion coefficients corresponding to the first subset of the plurality of frequency components and further to apply a second subset of non-zero inverse chromatic dispersion coefficients to a second optical signal.

Abstract: Embodiments of the disclosure include a method and apparatus for detecting and removing cycle slip. A phase-modulated signal having a plurality of phase-modulated symbols is received at an optical receiver, and, for each phase-modulated symbol, a phase-error estimate of a phase error of the phase-modulated symbol is generated. The presence of a cycle slip is then detected based on the phase-error estimates, and, a phase of each of one or more of the received phase-modulated symbols is adjusted to remove the detected cycle slip without adjusting a local oscillator.

Abstract: Embodiments of the disclosure include a method and apparatus for detecting and removing cycle slip. A phase-modulated signal having a plurality of phase-modulated symbols is received at an optical receiver, and, for each phase-modulated symbol, a phase-error estimate of a phase error of the phase-modulated symbol is generated. The presence of a cycle slip is then detected based on the phase-error estimates, and, a phase of each of one or more of the received phase-modulated symbols is adjusted to remove the detected cycle slip without adjusting a local oscillator.

Abstract: One aspect provides an optical communication system. The system includes an optical-to-digital converter, a frequency estimator and a symbol synchronizer. The optical-to-digital converter is configured to receive an optical OFDM bit stream including an OFDM symbol bearing payload data and a symbol header preceding the OFDM payload data. The frequency estimator is configured to determine a carrier frequency offset of the payload data from the symbol header. The symbol synchronizer is configured to determine a starting location of the payload data within the bit stream by cross-correlating a synchronization pattern within the symbol header with a model synchronization pattern stored by the symbol synchronizer.

Abstract: An apparatus, e.g. an optical receiver, includes an optical front end and an equalizer. The front end is configured for receiving an optical signal bearing first and second symbols on respective first and second polarization channels. The equalizer is configured to 1) select a first cost function if the first symbol has greater energy than the second symbol, 2) select a second different cost function if the second symbol has a greater energy than the first symbol, and 3) based on the selected cost function, update coefficients of an adaptive filter configured to demultiplex and equalize the first and second polarization channels.

Abstract: An apparatus, e.g. an optical receiver, includes an optical front end and an equalizer. The front end is configured for receiving an optical signal bearing first and second symbols on respective first and second polarization channels. The equalizer is configured to 1) select a first cost function if the first symbol has greater energy than the second symbol, 2) select a second different cost function if the second symbol has a greater energy than the first symbol, and 3) based on the selected cost function, update coefficients of an adaptive filter configured to demultiplex and equalize the first and second polarization channels.

Abstract: One aspect provides an optical communication system. The system includes an optical-to-digital converter, a frequency estimator and a symbol synchronizer. The optical-to-digital converter is configured to receive an optical OFDM bit stream including an OFDM symbol bearing payload data and a symbol header preceding the OFDM payload data. The frequency estimator is configured to determine a carrier frequency offset of the payload data from the symbol header. The symbol synchronizer is configured to determine a starting location of the payload data within the bit stream by cross-correlating a synchronization pattern within the symbol header with a model synchronization pattern stored by the symbol synchronizer.

Abstract: The invention refers to a device (1) for decoding an optical multi-level DPSK signal (E), the device (1) comprising: means for receiving the multi-level DPSK signal (E); at least two means (3) for transforming optical multi-level DPSK signals (E) into corresponding analog electrical signals (i); means (2) for splitting up the received multi-level DPSK signal (E) into at least two optical multi-level DPSK signals (E0), one for each of the opto-electrical transforming means (3); means (8) for processing electrical signals (i, e); and at least two means (6) for transforming the analog electrical signals (i) into corresponding electrical logical binary signals (e). In order to provide multi-level DPSK receiver (1) with a reduced complexity, it is suggested that concerning the signal flow within the device (1) the analog-to-logical-binary transformation means (6) are disposed before the processing means (8) and that the processing means (8) process electrical logical binary signals (e).

Abstract: The invention refers to a device (1) for decoding an optical multi-level DPSK signal (E), the device (1) comprising: means for receiving the multi-level DPSK signal (E); at least two means (3) for transforming optical multi-level DPSK signals (E) into corresponding analog electrical signals (i); means (2) for splitting up the received multi-level DPSK signal (E) into at least two optical multi-level DPSK signals (E0), one for each of the opto-electrical transforming means (3); means (8) for processing electrical signals (i, e); and at least two means (6) for transforming the analog electrical signals (i) into corresponding electrical logical binary signals (e). In order to provide multi-level DPSK receiver (1) with a reduced complexity, it is suggested that concerning the signal flow within the device (1) the analog-to-logical-binary transformation means (6) are disposed before the processing means (8) and that the processing means (8) process electrical logical binary signals (e).