Abstract: Methods of operating an optical communication system in coherent optical transmissions for metro applications. Relative to conventional solutions, the optical communication system can be implemented with reduced cost and can operate with reduced power consumption, while maintaining high data rate performance (e.g., 100G). Furthermore, a programmable transceiver enables compatibility with a range of different types of optical networks having varying performance and power tradeoffs. In one embodiment, the optical communication system uses 100 Gb/s dual-polarization 16-point quadrature amplitude modulation (DP-16QAM) with non-linear pre-compensation of Indium Phosphide (InP) optics for low power consumption.

Abstract: Methods of operating an optical communication system in coherent optical transmissions for metro applications. Relative to conventional solutions, the optical communication system can be implemented with reduced cost and can operate with reduced power consumption, while maintaining high data rate performance (e.g., 100 G). Furthermore, a programmable transceiver enables compatibility with a range of different types of optical networks having varying performance and power tradeoffs. In one embodiment, the optical communication system uses 100 Gb/s dual-polarization 16-point quadrature amplitude modulation (DP-16QAM) with non-linear pre-compensation of Indium Phosphide (InP) optics for low power consumption.

Abstract: A method and structure for signal propagation in a coherent optical receiver device. Asynchronous equalization helps to reduce complexity and power dissipation, and also improves the robustness of timing recovery. However, conventional devices using inverse interpolation filters ignore adaptation algorithms. The present invention provides for forward propagation and backward propagation. In the forward case, the filter input signal is forward propagated through a filter to the adaptation engine, while, in the backward case, the error signal is backward propagated through a filter to the asynchronous domain. Using such forward and backward propagation schemes reduces implementation complexity while providing optical device performance.

Abstract: Methods of operating an optical communication system in coherent optical transmissions for metro applications. Relative to conventional solutions, the optical communication system can be implemented with reduced cost and can operate with reduced power consumption, while maintaining high data rate performance (e.g., 100G). Furthermore, a programmable transceiver enables compatibility with a range of different types of optical networks having varying performance and power tradeoffs. In one embodiment, the optical communication system uses 100 Gb/s dual-polarization 16-point quadrature amplitude modulation (DP-16QAM) with non-linear pre-compensation of Indium Phosphide (InP) optics for low power consumption.

Abstract: A receiver (e.g., for a 10G fiber communications link) includes an interleaved ADC coupled to a multi-channel equalizer that can provide different equalization for different ADC channels within the interleaved ADC. That is, the multi-channel equalizer can compensate for channel-dependent impairments. In one approach, the multi-channel equalizer is a feedforward equalizer (FFE) coupled to a Viterbi decorder, for example, a sliding block Viterbi decoder (SBVD); and the FFE and/or the channel estimator for the Viterbi decoder are adapted using the LMS algorithm.

Abstract: A timing recovery system generates a sampling clock to synchronize sampling of a receiver to a symbol rate of an incoming signal. The input signal is received over an optical communication channel. The receiver generates a timing matrix representing coefficients of a timing tone detected in the input signal. The timing tone representing frequency and phase of a symbol clock of the input signal and has a non-zero timing tone energy. The receiver computes a rotation control signal based on the timing matrix that represents an amount of accumulated phase shift in the input signal relative to the sampling clock. A numerically controlled oscillator is controlled to adjust at least one of the phase and frequency of the sampling clock based on the rotation control signal.

Abstract: A coherent receiver comprises an ingress signal path having an ingress line-side interface, and an ingress host-side interface. The ingress signal path is configured to receive an analog signal vector at the ingress line-side interface, to demodulate the analog signal vector, and to output a digital data signal Fat the ingress host-side interface. The coherent receiver also comprises clock and timing circuitry configured to receive a single reference clock signal and to provide a plurality of modified ingress path clock signals to different components of the ingress signal path, the plurality of modified ingress path clock signals derived from the single reference clock signal and the plurality of modified ingress path clock signals having different clock rates. The receiver, transmitter, or transceiver can operate in a plurality of programmable operating modes to accommodate different modulation/de-modulation schemes, error correction code schemes, framing/mapping protocols, or other programmable features.

Abstract: A method and structure for signal propagation in a coherent optical receiver device. Asynchronous equalization helps to reduce complexity and power dissipation, and also improves the robustness of timing recovery. However, conventional devices using inverse interpolation filters ignore adaptation algorithms. The present invention provides for forward propagation and backward propagation. In the forward case, the filter input signal is forward propagated through a filter to the adaptation engine, while, in the backward case, the error signal is backward propagated through a filter to the asynchronous domain. Using such forward and backward propagation schemes reduces implementation complexity while providing optical device performance.

Abstract: A timing recovery system generates a sampling clock to synchronize sampling of a receiver to a symbol rate of an incoming signal. The input signal is received over an optical communication channel. The receiver generates a timing matrix representing coefficients of a timing tone detected in the input signal. The timing tone representing frequency and phase of a symbol clock of the input signal and has a non-zero timing tone energy. The receiver computes a rotation control signal based on the timing matrix that represents an amount of accumulated phase shift in the input signal relative to the sampling clock. A numerically controlled oscillator is controlled to adjust at least one of the phase and frequency of the sampling clock based on the rotation control signal.

Abstract: A receiver (e.g., for a 10 G fiber communications link) includes an interleaved ADC coupled to a multi-channel equalizer that can provide different equalization for different ADC channels within the interleaved ADC. That is, the multi-channel equalizer can compensate for channel-dependent impairments. In one approach, the multi-channel equalizer is a feedforward equalizer (FFE) coupled to a Viterbi decorder, for example, a sliding block Viterbi decoder (SBVD); and the FFE and/or the channel estimator for the Viterbi decoder are adapted using the LMS algorithm.

Abstract: A coherent receiver comprises an ingress signal path having an ingress line-side interface, and an ingress host-side interface. The ingress signal path is configured to receive an analog signal vector at the ingress line-side interface, to demodulate the analog signal vector, and to output a digital data signal Fat the ingress host-side interface. The coherent receiver also comprises clock and timing circuitry configured to receive a single reference clock signal and to provide a plurality of modified ingress path clock signals to different components of the ingress signal path, the plurality of modified ingress path clock signals derived from the single reference clock signal and the plurality of modified ingress path clock signals having different clock rates. The receiver, transmitter, or transceiver can operate in a plurality of programmable operating modes to accommodate different modulation/de-modulation schemes, error correction code schemes, framing/mapping protocols, or other programmable features.

Abstract: A timing recovery system generates a sampling clock to synchronize sampling of a receiver to a symbol rate of an incoming signal. The input signal is received over an optical communication channel. The receiver generates a timing matrix representing coefficients of a timing tone detected in the input signal. The timing tone representing frequency and phase of a symbol clock of the input signal and has a non-zero timing tone energy. The receiver computes a rotation control signal based on the timing matrix that represents an amount of accumulated phase shift in the input signal relative to the sampling clock. A numerically controlled oscillator is controlled to adjust at least one of the phase and frequency of the sampling clock based on the rotation control signal.

Abstract: A method and structure for signal propagation in a coherent optical receiver device. Asynchronous equalization helps to reduce complexity and power dissipation, and also improves the robustness of timing recovery. However, conventional devices using inverse interpolation filters ignore adaptation algorithms. The present invention provides for forward propagation and backward propagation. In the forward case, the filter input signal is forward propagated through a filter to the adaptation engine, while, in the backward case, the error signal is backward propagated through a filter to the asynchronous domain. Using such forward and backward propagation schemes reduces implementation complexity while providing optical device performance.

Abstract: A receiver (e.g., for a 10G fiber communications link) includes an interleaved ADC coupled to a multi-channel equalizer that can provide different equalization for different ADC channels within the interleaved ADC. That is, the multi-channel equalizer can compensate for channel-dependent impairments. In one approach, the multi-channel equalizer is a feedforward equalizer (FFE) coupled to a Viterbi decorder, for example, a sliding block Viterbi decoder (SBVD); and the FFE and/or the channel estimator for the Viterbi decoder are adapted using the LMS algorithm.

Abstract: A coherent receiver comprises an ingress signal path having an ingress line-side interface, and an ingress host-side interface. The ingress signal path is configured to receive an analog signal vector at the ingress line-side interface, to demodulate the analog signal vector, and to output a digital data signal Fat the ingress host-side interface. The coherent receiver also comprises clock and timing circuitry configured to receive a single reference clock signal and to provide a plurality of modified ingress path clock signals to different components of the ingress signal path, the plurality of modified ingress path clock signals derived from the single reference clock signal and the plurality of modified ingress path clock signals having different clock rates. The receiver, transmitter, or transceiver can operate in a plurality of programmable operating modes to accommodate different modulation/de-modulation schemes, error correction code schemes, framing/mapping protocols, or other programmable features.

Abstract: A timing recovery system generates a sampling clock to synchronize sampling of a receiver to a symbol rate of an incoming signal. The input signal is received over an optical communication channel. The receiver generates a timing matrix representing coefficients of a timing tone detected in the input signal. The timing tone representing frequency and phase of a symbol clock of the input signal and has a non-zero timing tone energy. The receiver computes a rotation control signal based on the timing matrix that represents an amount of accumulated phase shift in the input signal relative to the sampling clock. A numerically controlled oscillator is controlled to adjust at least one of the phase and frequency of the sampling clock based on the rotation control signal.

Abstract: A coherent receiver comprises an ingress signal path having an ingress line-side interface, and an ingress host-side interface. The ingress signal path is configured to receive an analog signal vector at the ingress line-side interface, to demodulate the analog signal vector, and to output a digital data signal Fat the ingress host-side interface. The coherent receiver also comprises clock and timing circuitry configured to receive a single reference clock signal and to provide a plurality of modified ingress path clock signals to different components of the ingress signal path, the plurality of modified ingress path clock signals derived from the single reference clock signal and the plurality of modified ingress path clock signals having different clock rates. The receiver, transmitter, or transceiver can operate in a plurality of programmable operating modes to accommodate different modulation/de-modulation schemes, error correction code schemes, framing/mapping protocols, or other programmable features.

Abstract: A method and structure for signal propagation in a coherent optical receiver device. Asynchronous equalization helps to reduce complexity and power dissipation, and also improves the robustness of timing recovery. However, conventional devices using inverse interpolation filters ignore adaptation algorithms. The present invention provides for forward propagation and backward propagation. In the forward case, the filter input signal is forward propagated through a filter to the adaptation engine, while, in the backward case, the error signal is backward propagated through a filter to the asynchronous domain. Using such forward and backward propagation schemes reduces implementation complexity while providing optical device performance.

Abstract: A receiver (e.g., for a 10G fiber communications link) includes an interleaved ADC coupled to a multi-channel equalizer that can provide different equalization for different ADC channels within the interleaved ADC. That is, the multi-channel equalizer can compensate for channel-dependent impairments. In one approach, the multi-channel equalizer is a feedforward equalizer (FFE) coupled to a Viterbi decorder, for example, a sliding block Viterbi decoder (SBVD); and the FFE and/or the channel estimator for the Viterbi decoder are adapted using the LMS algorithm.

Abstract: A timing recovery system generates a sampling clock to synchronize sampling of a receiver to a symbol rate of an incoming signal. The input signal is received over an optical communication channel. The receiver generates a timing matrix representing coefficients of a timing tone detected in the input signal. The timing tone representing frequency and phase of a symbol clock of the input signal and has a non-zero timing tone energy. The receiver computes a rotation control signal based on the timing matrix that represents an amount of accumulated phase shift in the input signal relative to the sampling clock. A numerically controlled oscillator is controlled to adjust at least one of the phase and frequency of the sampling clock based on the rotation control signal.