公开(公告)号：US20170310399A1

公开(公告)日：2017-10-26

申请号：US15517767

申请日：2015-10-05

Applicant: NEC Corporation

Inventor： Junichi ABE ,  Tatsuya NAKAMURA

IPC: H04B10/516 ,  H04B10/25

CPC classification number: H04B10/516 ,  H04B10/2504 ,  H04L27/36 ,  H04L27/38

Abstract: If a configuration is employed in which modulation schemes used for an optical communication system can be switched depending on transmission conditions, the power consumption increases and the control becomes complex; therefore, an optical transmitter according to an exemplary aspect of the present invention includes an encoding means for encoding digital signals to be transmitted under a predetermined transmission condition over an optical carrier wave by using one of a plurality of encoding methods; an encoding control means for selecting a predetermined encoding method corresponding to the predetermined transmission condition from among the plurality of encoding methods and causing the encoding means to operate in accordance with the predetermined encoding method; a mapping means for mapping output bit signals output from the encoding means to modulation symbols; and an optical modulation means for modulating the optical carrier wave based on symbol signals output from the mapping means.

公开(公告)号：US20160285558A1

公开(公告)日：2016-09-29

申请号：US14778208

申请日：2014-02-14

Applicant: NEC CORPORATION

Inventor： Junichi ABE

IPC: H04B10/508 ,  H04L25/03 ,  H04B10/516

CPC classification number: H04B10/508 ,  G02F1/0123 ,  G02F2001/212 ,  H04B10/516 ,  H04B10/588 ,  H04L25/03343

Abstract: A digital optical transmitter of the present invention comprises an optical modulator, pre-equalization factor computation means for generating transform functions for compensating waveform distortion to occur in the optical modulator, and pre-equalization signal generation means for outputting third data and fourth data after creating them by performing a pre-equalization process on first data and second data. Here, through the transform functions, the first data is added to the fourth data, in a manner depending on a characteristic of the optical modulator, and the second data is added to the third data, in a manner depending on a characteristic of the optical modulator.

Abstract translation: 本发明的数字光发射机包括光调制器，用于产生用于补偿在光调制器中发生的波形失真的变换函数的预均衡因子计算装置，以及用于在创建之后输出第三数据和第四数据的预均衡信号产生装置 它们通过对第一数据和第二数据执行预均衡处理。 这里，通过变换功能，以取决于光调制器的特性的方式将第一数据添加到第四数据，并且以取决于光学特性的方式将第二数据添加到第三数据 调制器。

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：US20230370166A1

公开(公告)日：2023-11-16

申请号：US18360078

申请日：2023-07-27

Applicant: NEC Corporation

Inventor： Junichi ABE ,  Tatsuya Nakamura

IPC: H04B10/516 ,  H04B10/25 ,  H04L27/38 ,  H04L27/36

CPC classification number: H04B10/516 ,  H04B10/25891 ,  H04L27/38 ,  H04L27/36

Abstract: If a configuration is employed in which modulation schemes used for an optical communication system can be switched depending on transmission conditions, the power consumption increases and the control becomes complex; therefore, an optical transmitter according to an exemplary aspect of the present invention includes an encoding means for encoding digital signals to be transmitted under a predetermined transmission condition over an optical carrier wave by using one of a plurality of encoding methods; an encoding control means for selecting a predetermined encoding method corresponding to the predetermined transmission condition from among the plurality of encoding methods and causing the encoding means to operate in accordance with the predetermined encoding method; a mapping means for mapping output bit signals output from the encoding means to modulation symbols; and an optical modulation means for modulating the optical carrier wave based on symbol signals output from the mapping means.

公开(公告)号：US20220170739A1

公开(公告)日：2022-06-02

申请号：US17599747

申请日：2019-04-03

Applicant: NEC Corporation

Inventor： Yoshimasa ONO ,  Akira TSUJI ,  Hidemi NOGUCHI ,  Junichi ABE

IPC: G01C3/06 ,  G01B11/30 ,  G01N21/956 ,  G01S17/06

Abstract: There is provided a surface abnormality detection device, and a system, capable of detecting an abnormal portion having a displacement below the distance measurement accuracy when detecting the abnormal portion on the surface of a structure. A surface abnormality detection device includes a classification means for classifying an object under measurement into one or more clusters having the same structure, based on position information at a plurality of points on a surface of the object under measurement; a determination means for determining a reflection brightness normal value of the cluster based on a distribution of reflection brightness values at a plurality of points on a surface of the cluster; and an identification means for identifying an abnormal portion on the surface of the cluster based on a difference between the reflection brightness normal value and the reflection brightness value at each of the plurality of points.

公开(公告)号：US20210041561A1

公开(公告)日：2021-02-11

申请号：US16762492

申请日：2018-12-05

Applicant: NEC Corporation

Inventor： Hidemi NOGUCHI ,  Junichi ABE

IPC: G01S17/36 ,  G01S17/10 ,  G01S17/87 ,  G01S7/487

Abstract: A range finding apparatus (2000) generates a plurality of range finding signals. The range finding apparatus (2000) generates transmission light acquired by performing at least one of quadrature modulation and polarization modulation on an optical carrier wave by using each of the generated range finding signals. The range finding apparatus (2000) transmits the generated transmission light. The range finding apparatus (2000) receives reflection light which is the transmission light reflected by an object to be measured. The range finding apparatus (2000) extracts a reception signal corresponding to each of the range finding signals by demodulating the reflection light. The range finding apparatus (2000) computes a distance to the object to be measured by using any one or more of the extracted reception signals

公开(公告)号：US20200322058A1

公开(公告)日：2020-10-08

申请号：US16872491

申请日：2020-05-12

Applicant: NEC Corporation

Inventor： Junichi ABE ,  Tatsuya NAKAMURA

IPC: H04B10/516 ,  H04L27/38 ,  H04L27/36 ,  H04B10/25

Abstract: If a configuration is employed in which modulation schemes used for an optical communication system can be switched depending on transmission conditions, the power consumption increases and the control becomes complex; therefore, an optical transmitter according to an exemplary aspect of the present invention includes an encoding means for encoding digital signals to be transmitted under a predetermined transmission condition over an optical carrier wave by using one of a plurality of encoding methods; an encoding control means for selecting a predetermined encoding method corresponding to the predetermined transmission condition from among the plurality of encoding methods and causing the encoding means to operate in accordance with the predetermined encoding method; a mapping means for mapping output bit signals output from the encoding means to modulation symbols; and an optical modulation means for modulating the optical carrier wave based on symbol signals output from the mapping means.

公开(公告)号：US20200021367A1

公开(公告)日：2020-01-16

申请号：US16583437

申请日：2019-09-26

Applicant: NEC Corporation

Inventor： Daisaku OGASAHARA ,  Junichi ABE

IPC: H04B10/61 ,  H04B10/079

Abstract: When a frequency deviation compensation amount is compensated for by use of frequency shift, a phase offset occurs between adjacent input blocks included in a plurality of input blocks as divided, with the result that an error occurs in a reconstructed bit sequence. A frequency deviation compensation system of the invention is characterized by comprising: a frequency deviation compensation means for compensating for a frequency deviation occurring in a signal by use of frequency shift; and a phase offset compensation means for compensating for a phase offset occurring, in the signal, due to the frequency shift.

公开(公告)号：US20180375585A1

公开(公告)日：2018-12-27

申请号：US16120989

申请日：2018-09-04

Applicant: NEC Corporation

Inventor： Junichi ABE ,  Tatsuya NAKAMURA

IPC: H04B10/516 ,  H04B10/25 ,  H04L27/36 ,  H04L27/38

CPC classification number: H04B10/516 ,  H04B10/2504 ,  H04L27/36 ,  H04L27/38

Abstract: If a configuration is employed in which modulation schemes used for an optical communication system can be switched depending on transmission conditions, the power consumption increases and the control becomes complex; therefore, an optical transmitter according to an exemplary aspect of the present invention includes an encoding means for encoding digital signals to be transmitted under a predetermined transmission condition over an optical carrier wave by using one of a plurality of encoding methods; an encoding control means for selecting a predetermined encoding method corresponding to the predetermined transmission condition from among the plurality of encoding methods and causing the encoding means to operate in accordance with the predetermined encoding method; a mapping means for mapping output bit signals output from the encoding means to modulation symbols; and an optical modulation means for modulating the optical carrier wave based on symbol signals output from the mapping means.

公开(公告)号：US20180013409A1

公开(公告)日：2018-01-11

申请号：US15544042

申请日：2016-01-14

Applicant: NEC CORPORATION

Inventor： Atsufumi SHIBAYAMA ,  Junichi ABE ,  Kohei HOSOKAWA

IPC: H03H17/02 ,  G06F17/14

CPC classification number: H03H17/0248 ,  G06F17/14 ,  H03H17/0202 ,  H03H17/0213 ,  H03H2017/0245

Abstract: Provided is a digital filter circuit in which a filter coefficient can be easily changed, for which circuit scale and power consumption can be reduced, and which carries out digital filter processing in a frequency domain. This digital filter circuit includes: a separating circuit for separating a first complex number signal, of a frequency domain that was subjected to Fourier transform, into a real number portion and an imaginary number portion; a filter coefficient generating circuit for generating a first frequency domain filter coefficient from a first input filter coefficient and a third input filter coefficient, and for generating a second frequency domain filter coefficient from a second input filter coefficient and the third input filter coefficient; a first filter that filters the separated real number portion using the first frequency domain filter coefficient; a second filter that filters the separated imaginary number portion using the second frequency domain filter coefficient; and a combining circuit for combining the output from the two filters.