公开(公告)号：US20230097741A1

公开(公告)日：2023-03-30

申请号：US17909884

申请日：2020-03-11

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Kengo HORIKOSHI ,  Masanori NAKAMURA ,  Seiji OKAMOTO ,  Etsushi YAMAZAKI ,  Asuka MATSUSHITA ,  Takeo SASAI

IPC: H04B10/2525 ,  H04B10/61

Abstract: 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.

公开(公告)号：US20230076671A1

公开(公告)日：2023-03-09

申请号：US17797743

申请日：2020-02-17

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takafumi TANAKA ,  Hideki NISHIZAWA ,  Tetsuro INUI ,  Seiki KUWABARA ,  Shuto YAMAMOTO ,  Seiji OKAMOTO

IPC: H04B10/27 ,  H04B10/07

Abstract: A virtual environment optical communication network is generated by setting configuration parameters of physical packages of a real environment optical communication network in package emulators that a computer program has virtually constructed to implement the physical packages, the real environment optical communication network being constructed by a plurality of node devices in which the physical packages are mounted, pieces of configuration data are generated based on pieces of resource data indicating resources required for optical paths detected based on acquired configuration parameters and a requested transmission mode, optical paths are set in the virtual environment optical communication network based on the generated pieces of configuration data, and optical paths are set in the real environment optical communication network based on the pieces of configuration data that have been used to set the optical paths.

公开(公告)号：US20220416890A1

公开(公告)日：2022-12-29

申请号：US17782957

申请日：2019-12-16

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takeo SASAI ,  Fukutaro HAMAOKA ,  Masanori NAKAMURA ,  Seiji OKAMOTO

IPC: H04B10/2543 ,  H04B10/61

Abstract: 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.

公开(公告)号：US20220303003A1

公开(公告)日：2022-09-22

申请号：US17635275

申请日：2019-09-17

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Kengo HORIKOSHI ,  Masanori NAKAMURA ,  Seiji OKAMOTO ,  Hideki NISHIZAWA ,  Etsushi YAMAZAKI

IPC: H04B10/079 ,  H04B10/61 ,  H04B10/2569

Abstract: A signal processing apparatus includes: a coefficient update unit configured to approximate a characteristic of a transmission line of an optical signal by a first tap coefficient vector of which an LO norm is a predetermined value or less; a zeroing unit configured to generate a second tap coefficient vector by replacing, with 0, a tap coefficient of which an absolute value is less than a threshold among tap coefficients of the first tap coefficient vector; and an adaptive filter configured to perform, based on the second tap coefficient vector, adaptive equalization processing on a digital signal corresponding to an optical signal received via the transmission line.

公开(公告)号：US20220069921A1

公开(公告)日：2022-03-03

申请号：US17424766

申请日：2020-01-15

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Akira MASUDA ,  Fukutaro HAMAOKA ,  Shuto YAMAMOTO ,  Seiji OKAMOTO ,  Kengo HORIKOSHI ,  Masanori NAKAMURA ,  Asuka MATSUSHITA ,  Yoshiaki KISAKA

IPC: H04B10/69 ,  H04B10/548 ,  H04B10/67

Abstract: There are provided an optical transmission apparatus that subjects a transmission signal including a plurality of sequences to Hadamard transform to obtain a signal in which a predetermined delay is added to one of the sequences, optically modulates the obtained signal, and transmits the modulated signal, and an optical reception apparatus that demodulates a reception signal received from the optical transmission apparatus by subjecting the reception signal to adaptive equalization processing with a predetermined number of taps. The optical reception apparatus includes: an adaptive equalization processing unit that subjects the reception signal to adaptive equalization processing of wavelength distortion compensation with a number of taps obtained by subtracting a number in accordance with the delay from the predetermined number of taps; a delay compensation unit that subjects the reception signal subjected to the wavelength distortion compensation to delay compensation in accordance with the delay; and an inverse Hadamard transform unit that subjects the reception signal subjected to the delay compensation to inverse Hadamard transform.

公开(公告)号：US20210384983A1

公开(公告)日：2021-12-09

申请号：US17265823

申请日：2019-07-02

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Seiji OKAMOTO ,  Fukutaro HAMAOKA ,  Masanori NAKAMURA ,  Yoshiaki KISAKA

IPC: H04B10/516 ,  H04B10/61 ,  H04B10/69 ,  H04L27/36 ,  H04L27/38

Abstract: There is provided a communication system, wherein: an optical transmission apparatus has: a first storage unit that stores amplitude distribution information, which is information representing a distribution of occurrence probabilities of symbols of an optical signal, in association with a modulation rate of an optical signal; a control unit that selects the modulation rate based on a signal band that is a band determined by the modulation rate and a device band that is a band in which a transmission path and the like allow passage of an optical signal, and controls an occurrence probability of a symbol of an optical signal based on the amplitude distribution information; and an optical transmitter that transmits an optical signal of a symbol of which the occurrence probability is controlled; and an optical reception apparatus has: an optical receiver that receives an optical signal of a symbol; a second storage unit that stores the amplitude distribution information in association with the modulation rate; and a decoding unit that detects the selected modulation rate, and decodes a symbol of a received optical signal based on the amplitude distribution information associated with the detected modulation rate.

公开(公告)号：US20210367675A1

公开(公告)日：2021-11-25

申请号：US17056409

申请日：2019-05-08

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Masanori NAKAMURA ,  Seiji OKAMOTO ,  Etsushi YAMAZAKI ,  Yoshiaki KISAKA

IPC: H04B10/50 ,  H04B10/69

Abstract: An optical communication system is provided in which a serial/parallel converting unit outputs bit sequences of sequence groups a number of which is determined by a logarithmic value and a bit sequence of a highest-order sequence group, a converting unit converts the bit sequence of the sequence group input to the converting unit into a bit sequence for which a probability of occurrence of 0 or a probability of occurrence of 1 is a predetermined probability of occurrence, a selecting unit acquires a bit sequence for which the probability of occurrence is converted by a converting unit higher in order than the converting unit for the selecting unit, and selects an order of output of a symbol to other selecting units in the sequence groups higher in order than the selecting unit in accordance with the acquired bit sequence, a multiplication unit multiplies a value representing the symbol selected by a highest-order selecting unit, by a number in accordance with the bit sequence of the highest order sequence group, a transmission unit transmits an optical signal based on a result of the multiplication by the number, an optical receiver includes a reception unit and a demodulation unit, and the reception unit receives the optical signal, and performs demodulation processing.

公开(公告)号：US20210203363A1

公开(公告)日：2021-07-01

申请号：US17056719

申请日：2019-05-09

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Seiji OKAMOTO ,  Etsushi YAMAZAKI ,  Masanori NAKAMURA ,  Yoshiaki KISAKA ,  Masahito TOMIZAWA

IPC: H03M13/35 ,  H04L1/00 ,  H04L1/20

Abstract: A signal processing device includes a distributing unit and a plurality of correcting units with different processing performance, the distributing unit distributes a bit sequence having a first number of bits to the first correcting unit, and a bit sequence having a second number of bits less than the first number of bits to the second correcting unit having lower processing performance than the first correcting unit, the first correcting unit applies error correction processing to the bit sequence having the first number of bits distributed to the first correcting unit, and the second correcting unit applies error correction processing to the bit sequence having the second number of bits distributed to the second correcting unit.

公开(公告)号：US20190165868A1

公开(公告)日：2019-05-30

申请号：US16092391

申请日：2017-06-21

Applicant: NTT ELECTRONICS CORPORATION ,  NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Yasuharu ONUMA ,  Etsushi YAMAZAKI ,  Tomohiro TAKAMUKU ,  Masahiro TACHIBANA ,  Mitsuteru YOSHIDA ,  Masahito TOMIZAWA ,  Seiji OKAMOTO

IPC: H04B10/61 ,  H04L7/00 ,  H04L7/08

Abstract: Fourier transform is performed on a reception signal to obtain a first calculation value. Fourier transform is performed on a known signal to obtain a second calculation value. The first calculation value is divided by the second calculation value to obtain a third calculation value. Inverse Fourier transform is performed on the third calculation value to obtain a fourth calculation value. A maximum value of an amplitude of the fourth calculation value and a sample point at which the maximum value is obtained are detected. The position of the known signal in the reception signal is detected from the sample point at which the maximum value is obtained.

公开(公告)号：US20150372766A1

公开(公告)日：2015-12-24

申请号：US14766635

申请日：2014-02-13

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Mitsuteru YOSHIDA ,  Etsushi YAMAZAKI ,  Seiji OKAMOTO ,  Hiroyuki UZAWA ,  Kengo HORIKOSHI ,  Koichi ISHIHARA ,  Takayuki KOBAYASHI ,  Yoshiaki KISAKA ,  Masahito TOMIZAWA ,  Naoki FUJIWARA ,  Tomoyoshi KATAOKA ,  Kazushige YONENAGA

IPC: H04B10/61 ,  H04B10/2507 ,  H04J14/06 ,  H04B10/516

CPC classification number: H04B10/6165 ,  H04B10/2507 ,  H04B10/516 ,  H04B10/61 ,  H04J14/06 ,  H04L27/38 ,  H04L2027/0067 ,  H04L2027/0095

Abstract: An increase in circuit scale is suppressed and a phase variation caused in a transmission path or the like is compensated for. An optical transmission system includes: a pilot symbol detection unit which detects a plurality of pilot symbols intermittently inserted into a received complex electric field signal that is obtained through coherent detection for a received optical signal; an error signal computation unit which calculates a complex electric field error signal indicating a phase variation at each pilot symbol based on the pilot symbols detected by the pilot symbol detection unit and a predetermined reference symbol; a compensation electric field signal generation unit which estimates a phase variation between the pilot symbols in the received complex electric field signal using filter processing based on the complex electric field error signal calculated by the error signal computation unit; and a phase noise compensation unit which performs phase compensation for the received complex electric field signal based on the phase variation between the pilot symbols estimated by the compensation electric field signal generation unit.

Abstract translation: 抑制电路规模的增加，并且补偿在传输路径等中引起的相位变化。 光传输系统包括：导频符号检测单元，其检测间歇地插入到通过接收的光信号的相干检测获得的接收复电场信号中的多个导频符号; 误差信号计算单元，基于由导频符号检测单元检测的导频符号和预定的参考符号，计算指示每个导频符号的相位变化的复电场误差信号; 补偿电场信号生成单元，其基于由所述误差信号计算单元计算的复电场误差信号，使用滤波处理来估计所述接收复电场信号中的导频符号之间的相位变化; 以及相位噪声补偿单元，其基于由补偿电场信号生成单元估计的导频符号之间的相位变化，对接收到的复数电场信号进行相位补偿。