Future Wei Technologies, Inc.

Huawei Technologies Co., Limited

Qing Guo

Yu Sheng Bai

Fei Zhu

Yan Cui

YuSheng Bai

Murali Krishnan

Samina Chowdhury

Wei-Ren Peng

Yanjun Zhu

Jianfeng Wang

Systems and methods for creating and using a first and second group of training sequences in a training-aided single-carrier frequency domain equalization system. The first group of training sequences are conventional training sequences and the second group of training sequences are 90&#xb0;-rotated versions of the first group of training sequences.

Training sequences with enhanced IQ imbalance tolerances for training-aided frequency domain equalization

An optical transceiver in an optical communications network, comprising a receiver configured to receive an optical signal comprising an X-polarization component and a Y-polarization component. The optical transceiver further comprises a processor coupled to the receiver and configured to determine a chromatic dispersion (CD) estimate and a local oscillator frequency offset (LOFO) estimate based on a relationship between a plurality of CD values and a plurality of LOFO values. The optical transceiver further comprises a transmitter coupled to the processor and configured to transmit the CD estimate, the LOFO estimate, and the optical signal to a downstream component in the optical communications network.

Joint acquisition of chromatic dispersion and frequency offset in optical systems

An optical transceiver in an optical communications network, comprising a receiver configured to receive an optical signal comprising an X-polarization component that comprises a first frame and a Y-polarization component that comprises a second frame. The optical transceiver also comprises a processor coupled to the receiver and configured to determine, in a time domain, a phase estimate according to the first frame and the second frame, determine, in a frequency domain, a channel estimate for the optical signal according to a relationship between the first frame, the second frame, and the phase estimate, and determine a compensated optical signal according to the channel estimate. The optical transceiver further comprises a transmitter coupled to the processor and configured to transmit the compensated optical signal to a downstream component in the optical communications network.

Frequency domain optical channel estimation

A signal processing method including obtaining, using an optical receiver, a data signal that comprises one or more pairs of pilot tones and a plurality of subcarrier signals, identifying the one or more pairs of pilot tones, determining a local oscillator frequency offset estimation for the data signal using the one or more pairs of pilot tones, wherein the local oscillator frequency offset estimation indicates a frequency offset, and compensating the data signal in accordance with the local oscillator frequency offset estimation. A signal processing method including obtaining, using an optical receiver, a data signal that comprises one or more pairs of pilot tones and a plurality of subcarrier signals, identifying the one or more pairs of pilot tones, determining a chromatic dispersion estimation for the data signal using the one or more pairs of pilot tones, and compensating the data signal in accordance with the chromatic dispersion estimation.

Estimation and compensation of local oscillator frequency offset and chromatic dispersion using pilot tones in spectral-shaping subcarrier modulation

A method comprising applying an In-phase (I) offset to an I component of an orthogonal pseudo-random coded direct current (DC) bias signal, applying a Quadrature-phase (Q) offset to a Q component of the orthogonal pseudo-random coded DC bias signal, applying an I dither signal to an I Mach-Zehnder modulator (MZM), wherein the I dither signal is based on the I component of the orthogonal pseudo-random coded DC bias signal, applying a Q dither signal to a Q MZM, wherein the Q dither signal is based on the Q component of the orthogonal pseudo-random coded DC bias signal, and performing arbitrary waveform generation (AWG) by modulating an analog data signal onto an optical carrier signal via the MZMs, wherein the I offset and the Q offset are selected to mitigate crosstalk between the I MZM and the Q MZM due to a finite extinction ratio.

Mach-Zehnder modulator bias control for arbitrary waveform generation

An optical receiver comprising a frontend configured to receive an optical signal and convert the optical signal into a plurality of digital electrical signals comprising a plurality of spectrally shaped subcarrier signals carrying symbol mapped data information, and a digital signal processor (DSP) unit coupled to the frontend and configured to receive the digital signals from the frontend, demulitplex the digital signals into the subcarrier signals, and compensate chromatic dispersion (CD) for each of the subcarrier signals by applying an equalizer, wherein each of the subcarrier signals is associated with a unique tone frequency and a unique spectral shape. Also disclosed is an optical transmitter comprising a digital signal processor (DSP) unit configured to map data symbols onto a plurality of electrical subcarrier signals that are non-overlapping and spectrally shaped in a frequency domain.

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Dublin, CA, United States of America

Qing Guo