公开(公告)号：US20250038860A1

公开(公告)日：2025-01-30

申请号：US18717067

申请日：2022-01-04

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Kyo MINOGUCHI ,  Masanori NAKAMURA ,  Seiji OKAMOTO ,  Yoshiaki KISAKA

IPC: H04B10/61 ,  H04B10/079

Abstract: An estimation method in an optical transmission system that performs communication by a digital coherent system including an optical transmission device and an optical reception device, the estimation method including calculating a ratio of a linearly transformed amount after converting a tap coefficient of a digital filter included in the optical reception device into a frequency domain signal by digital Fourier transform, and estimating a physical quantity related to at least a response between the optical transmission device and the optical reception device based on amplitude and phase information of the ratio of the calculated linearly transformed amount.

公开(公告)号：US20210367670A1

公开(公告)日：2021-11-25

申请号：US17291170

申请日：2019-11-07

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Shuto YAMAMOTO ,  Seiji OKAMOTO ,  Akira MASUDA ,  Hiroki TANIGUCHI ,  Yoshiaki KISAKA

IPC: H04B10/2507 ,  H04B10/516 ,  H03M13/41 ,  H04B10/61 ,  H04L25/49

Abstract: An optical transmission system including an optical transmitter and an optical receiver, wherein the optical transmitter includes a signal coding unit that performs non-linear block coding on an M (M is an integer greater than or equal to 1)-value symbol sequence or a bit sequence input as data information to generate an L (L is an integer greater than or equal to 2, L>M)-value symbol sequence that corresponds to the M-value symbol sequence or the bit sequence in one-to-one correspondence, a digital-to-analog conversion unit that converts the generated L-value symbol sequence to an analog signal, and a modulator that generates an optical modulation signal by performing modulation based on the analog signal, and the optical receiver includes a light receiving unit that receives the optical modulation signal transmitted from the optical transmitter and converts the optical modulation signal to an electrical signal, and a signal decoding unit that restores the M-value symbol sequence or the bit sequence by performing processing that is the reverse of processing performed by the signal coding unit, on the electrical signal.

公开(公告)号：US20170070296A1

公开(公告)日：2017-03-09

申请号：US15122582

申请日：2015-03-17

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Seiji OKAMOTO ,  Koichi ISHIHARA ,  Etsushi YAMAZAKI ,  Mitsuteru YOSHIDA ,  Tomoyoshi KATAOKA ,  Kazushige YONENAGA ,  Yoshiaki KISAKA ,  Masanori NAKAMURA ,  Masahito TOMIZAWA

IPC: H04B10/516 ,  H04B10/508

CPC classification number: H04B10/516 ,  H04B10/0775 ,  H04B10/2513 ,  H04B10/2557 ,  H04B10/508 ,  H04L27/3455 ,  H04L27/3483 ,  H04L27/366

Abstract: An optical signal transmission apparatus includes a modulation unit which modulates a transmission signal, a training signal sequence generation unit which generates a plurality of signal sequences having power concentrated in a plurality of different frequency bands, at least one of an amplitude and a phase of the plurality of signal sequences being modulated, as a training signal sequence, a signal multiplexing unit which appends the training signal sequence to the transmission signal, and an electro-optical conversion unit which converts a signal sequence obtained by appending the training signal sequence to the transmission signal into an optical signal and transmits the optical signal.

Abstract translation: 光信号传输装置包括：调制单元，其对发送信号进行调制;训练信号序列生成单元，生成具有集中在多个不同频带的功率的多个信号序列，所述训练信号序列生成单元的振幅和相位中的至少一个 多个信号序列作为训练信号序列被调制为将训练信号序列附加到传输信号的信号复用单元，以及电光转换单元，其将通过将训练信号序列附加到传输获得的信号序列 信号转换为光信号并发送光信号。

公开(公告)号：US20220094440A1

公开(公告)日：2022-03-24

申请号：US17420845

申请日：2020-01-06

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Seiji OKAMOTO ,  Yoshiaki KISAKA ,  Masanori NAKAMURA

IPC: H04B10/61 ,  H04B10/2513

Abstract: An optical receiving device that divides receive signals obtained by receiving an optical signal using a coherent detection scheme into a plurality of frequency bands, matches timing of the receive signals along a time axis between the frequency bands resulting from the division, performs a combining process of combining the receive signals contained in the plurality of frequency bands, and compensates the receive signals for waveform distortion either before or after the combining process, includes: a first wavelength dispersion compensation unit adapted to compensate the receive signals for waveform distortion in each of the frequency bands resulting from the division; a first nonlinear compensation unit adapted to compensate the receive signals belonging to each of the frequency bands and timed with each other in a time domain for a nonlinear optical effect; and a second wavelength dispersion compensation unit adapted to compensate the receive signals belonging to each of the frequency bands and compensated for the nonlinear optical effect for wavelength dispersion in each of the frequency bands.

公开(公告)号：US20220038180A1

公开(公告)日：2022-02-03

申请号：US17278627

申请日：2019-08-27

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Kyo MINOGUCHI ,  Etsushi YAMAZAKI ,  Seiji OKAMOTO ,  Yoshiaki KISAKA

IPC: H04B10/2513

Abstract: Provided is a chromatic dispersion compensation method including: dividing a reception signal obtained by receiving an optical signal using a coherent detection scheme into a plurality of frequency bands; adjusting a timing on a time axis of the reception signal for each of the divided frequency bands; performing combination processing for combining the reception signals included in the plurality of frequency bands; performing chromatic dispersion compensation on the reception signal at any timing before or after the combination processing; selecting, before the combination processing, sections in which overlapping parts determined based on lengths of overlap parts are generated; outputting the reception signal for each of the selected sections as a division processing block; and removing the overlap parts from both ends of a processing block generated by combination of the division processing blocks in the combination processing so as to be continuous on a frequency axis.

公开(公告)号：US20210211218A1

公开(公告)日：2021-07-08

申请号：US17059238

申请日：2019-05-20

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Fukutaro HAMAOKA ,  Kyo MINOGUCHI ,  Seiji OKAMOTO ,  Yoshiaki KISAKA

IPC: H04J14/02 ,  H04B10/2537 ,  H04B10/548

Abstract: An optical transmission system includes an optical transmitter, an optical receiver, and a control apparatus. The control apparatus repeatedly performs an adjustment process for adjusting power of an optical signal of a frequency band to be adjusted while switching the frequency band to be adjusted between at least two frequency bands including at least a frequency band where stimulated Raman scattering occurs among frequency bands that are multiplexed in a multiplexed optical signal transmitted by the optical transmission system. In the adjustment process, when power of an optical signal of the frequency band to be adjusted transmitted from the optical transmitter has been changed, the control apparatus determines the power of the optical signal of the frequency band to be adjusted on the basis of a signal quality measured by the optical receiver that has received the optical signal.

公开(公告)号：US20190273560A1

公开(公告)日：2019-09-05

申请号：US16320065

申请日：2017-07-26

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Kengo HORIKOSHI ,  Seiji OKAMOTO ,  Asuka MATSUSHITA ,  Mitsuteru YOSHIDA ,  Fukutaro HAMAOKA ,  Yoshiaki YAMADA ,  Yoshiaki KISAKA

IPC: H04B10/516 ,  H04J14/08 ,  H04B10/60

Abstract: An optical transmitter of an optical data transmission system transmitting data through an optical fiber transmission path includes a main signal generator that converts first transmission data into a predetermined signal format to generate a first signal, a DCSK modulator that DCSK-modulates second transmission data to generate a second signal, a signal-multiplexer that performs time-division multiplexing of the first signal and the second signal, and an electro-optical converter that converts a multiplexed signal obtained by the time-division multiplexing of the signal-multiplexer from an electric signal into an optical signal, and outputs the optical signal to the optical fiber transmission path.

公开(公告)号：US20190013876A1

公开(公告)日：2019-01-10

申请号：US15748892

申请日：2016-10-17

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION ,  NTT Electronics Corporation

Inventor： Kengo HORIKOSHI ,  Mitsuteru YOSHIDA ,  Seiji OKAMOTO ,  Eiichi HOSOYA ,  Etsushi YAMAZAKI ,  Yasuharu ONUMA ,  Tomohiro TAKAMUKU ,  Naoki MIURA ,  Sadayuki YASUDA

IPC: H04B10/61 ,  H04B10/532 ,  H04J14/06

CPC classification number: H04B10/6166 ,  G02F1/21 ,  G02F2001/212 ,  H04B10/2513 ,  H04B10/2569 ,  H04B10/532 ,  H04B10/616 ,  H04B10/6161 ,  H04B10/6162 ,  H04B10/6164 ,  H04B10/6165 ,  H04B2210/252 ,  H04J14/06 ,  H04L27/0014 ,  H04L27/362 ,  H04L27/3818 ,  H04L27/3827 ,  H04L27/3863 ,  H04L2027/0026

Abstract: A coherent optical reception device includes a local oscillation laser that supplies laser light, a coherent optical reception front-end unit that receives a multi-level modulated optical signal, demodulates the optical signal on the basis of the laser light, and converts a demodulated optical signal into an electrical analog signal, an analog-to-digital converter that converts the analog signal into a digital signal, a compensation unit that compensates for an influence of dispersion due to a wavelength or a polarized wave of the optical signal and recovers a carrier phase of the digital signal, a constellation distortion compensation unit that compensates for constellation distortion of the multi-level modulation included in the digital signal in which an influence of dispersion is compensated for by the compensation unit, and an error correction decoding unit that performs error correction of the digital signal in which the constellation distortion is compensated for.

公开(公告)号：US20240187107A1

公开(公告)日：2024-06-06

申请号：US18283244

申请日：2021-03-24

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Kengo HORIKOSHI ,  Etsushi YAMAZAKI ,  Seiji OKAMOTO

IPC: H04B10/61

CPC classification number: H04B10/6165

Abstract: A frequency offset estimation device includes a correlation processing unit that obtains a correlation pattern that is a waveform pattern indicating a correlation between a reception signal spectrum and a detection pattern based on a power spectrum of the reception signal or the reception signal spectrum indicating an amplitude spectrum based on the power spectrum and the detection pattern that is a predetermined waveform pattern, and



an estimation unit that estimates a frequency offset amount based on a peak position of the correlation pattern obtained by the correlation processing unit.

公开(公告)号：US20240007195A1

公开(公告)日：2024-01-04

申请号：US18039125

申请日：2020-12-14

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Kengo HORIKOSHI ,  Seiji OKAMOTO ,  Masanori NAKAMURA

IPC: H04B10/61 ,  H04J14/06

CPC classification number: H04B10/6162 ,  H04J14/06 ,  H04B10/6166

Abstract: An adaptive equalizer includes an updating unit that updates a step size of a vector of a tap coefficient used for controlling an adaptive filter based on a time-series update vector in accordance with a time-series input and output of the adaptive filter that tracks a polarization state of an optical signal received by a coherent optical receiver. The updating unit updates the step size based on a DC gain of the update vector. The updating unit may update the step size for each update vector component based on a DC gain for each update vector component.