公开(公告)号：US20240121007A1

公开(公告)日：2024-04-11

申请号：US18374863

申请日：2023-09-29

Applicant: NEC Corporation

Inventor： Masaki SATO

IPC: H04B10/61

CPC classification number: H04B10/6161

Abstract: A distortion compensation filter whose filter coefficient is adaptively controlled compensates for a distortion included in a reception signal obtained by performing coherent reception of a signal transmitted from a transmitter in a receiver. A group delay ripple calculation device calculates a group delay included in the reception signal based on a filter coefficient of a distortion compensation filter and calculates group delay ripple from the calculated group delay. The feedback calculation unit calculates a phase response based on the calculated group delay ripple. The feedback calculation unit feeds the calculated phase response back to one or more filters having a phase compensation function disposed in a stage before an adaptive equalization filter included in the receiver, and causes one or more filters to at least partially compensate for the group delay ripple.

公开(公告)号：US20230119766A1

公开(公告)日：2023-04-20

申请号：US17914442

申请日：2021-03-04

Applicant: NEC Corporation

Inventor： Masaki SATO

IPC: H04J14/06 ,  G01J4/04

Abstract: In order to estimate a polarization fluctuation speed with high accuracy independently of the quality of a received signal, a polarization-fluctuation estimating device according to the present invention includes: a polarization de-multiplexing unit that generates a single-polarization optical signal from an input polarization-multiplexed optical signal; a photoelectric converting unit that converts the generated optical signal into an electrical signal; and an estimation unit that estimates the polarization fluctuation speed of the polarization-multiplexed optical signal in accordance with the electrical signal.

公开(公告)号：US20150095743A1

公开(公告)日：2015-04-02

申请号：US14502451

申请日：2014-09-30

Applicant: NEC CORPORATION

Inventor： Masaki SATO

IPC: H03M13/35 ,  H04J14/06 ,  G06F11/10

CPC classification number: H03M13/353 ,  H04B10/00 ,  H04B10/0775 ,  H04B10/516 ,  H04B10/616 ,  H04J14/06 ,  H04L1/00 ,  H04L1/0009

Abstract: A transmission device transmitting a polarization-multiplexed optical signal includes: a frame encoder configured to encode an electric signal in accordance with a predetermined frame format; an error correction encoder configured to provide encoded signal data as a result of the encoding by the frame encoder with a predetermined error correction code; and a transmission loss information acquiring part configured to acquire transmission loss information based on a loss that the encoded signal data provided with the error correction code incurs when the encoded signal data is transmitted, from a receiving device as a transmission destination. The error correction encoder adjusts a redundancy of the error correction code given to the encoded signal data, based on the transmission loss information acquired by the transmission loss information acquiring part.

Abstract translation: 发送偏振复用光信号的发送装置包括：帧编码器，被配置为根据预定帧格式对电信号进行编码; 纠错编码器，被配置为通过帧编码器以预定的纠错码提供作为编码结果的编码信号数据; 以及发送损失信息获取部件，被配置为从作为发送目的地的接收装置，基于当发送编码信号数据时提供有纠错码的编码信号数据的损失获取传输损失信息。 错误校正编码器基于由传输损失信息获取部分获取的传输损失信息来调整给予编码信号数据的纠错码的冗余度。

公开(公告)号：US20220166534A1

公开(公告)日：2022-05-26

申请号：US17440420

申请日：2020-02-04

Applicant: NEC Corporation

Inventor： Hidemi NOGUCHI ,  Junichi ABE ,  Masaki SATO

IPC: H04J14/02 ,  H04B10/2507 ,  H04B10/61 ,  H04B10/50

Abstract: To suppress the deterioration of the characteristics of a MIMO equalizer as well as minimizing an increase in circuit size in spite of the occurrence of signal spectrum narrowing and asymmetric spectrum degradation, a wavelength-division multiplexing optical transmission system (10) according to an embodiment includes a transmitter (1) that generates one channel signal by wavelength-division multiplexing a plurality of subcarrier signals so as to overlap each other and transmits the channel signal, and a receiver (2) that separates a received channel signal into subcarrier signals, and performs equalization using an MIMO equalizer (3) including a FDE-MIMO equalizer (4) and a TDE-MIMO equalizer (5) on each of the separated subcarrier signals.

公开(公告)号：US20240056197A1

公开(公告)日：2024-02-15

申请号：US17766314

申请日：2020-10-05

Applicant: NEC Corporation

Inventor： Masaki SATO ,  Hidemi NOGUCHI ,  Junichi ABE

IPC: H04B10/61 ,  H04B3/06

CPC classification number: H04B10/616 ,  H04B3/06

Abstract: An optical signal processing circuit (1) includes: an FDE-MIMO equalizer (2) configured to generate, based on continuous subcarrier signals including a target subcarrier signal in an optical multicarrier signal to be received, the continuous subcarrier signals that have been subjected to frequency-domain MIMO equalization processing; and a TDE-MIMO equalizer (3) configured to generate, based on the continuous subcarrier signals that have been subjected to the frequency-domain MIMO equalization processing, the target subcarrier signal that has been subjected to time-domain MIMO equalization processing.

公开(公告)号：US20240045238A1

公开(公告)日：2024-02-08

申请号：US18266430

申请日：2020-12-25

Applicant: NEC Corporation

Inventor： Mingqi WU ,  Emmanuel LE TAILLANDIER GABORY ,  Kazushi MURAOKA ,  Masaki SATO

IPC: G02F1/01 ,  H04B10/50 ,  G02B27/10

CPC classification number: G02F1/0123 ,  H04B10/5053 ,  G02B27/106

Abstract: It is difficult to carry out automatic bias control to an optical modulator without a dither signal with a simple configuration, therefore, an optical transmitter comprising the controller configured to adjust an adjusted bias voltage based on the coupled optical signal, the adjusted bias voltage being one of a first bias voltage applied to the first optical modulator, a second bias voltage applied to the second optical modulator and a third bias voltage applied to the third optical modulator and maintain a value of bias voltages other than the adjusted voltage in the first bias voltage, the second bias voltage and the third voltage.