公开(公告)号：US20160105160A1

公开(公告)日：2016-04-14

申请号：US14891844

申请日：2014-06-02

Applicant: NEC CORPORATION

Inventor： Kohei HOSOKAWA

IPC: H03H17/02 ,  H03H17/04

CPC classification number: H03H17/0261 ,  H03H17/04

Abstract: Provided is a digital filter device including data rearrangement means for executing rearrangement of input data and outputting rearranged data, intermediate data calculation means for processing the rearranged data input at a specific time and generating intermediate data, filter output first calculation means for calculating a first output value at the specific time by use of the intermediate data, delay means for delaying the rearranged data by processing time taken in the intermediate data calculation means and the file output first calculation means, and filter output second calculation means for inputting output values from the delay means and the filter output first calculation means, calculating a second output value at a time other than the specific time, and outputting a filter output value obtained by adding up the first and second output values. Consequently, it becomes feasible to reduce a circuit scale without impairing performance of a digital filter used in nonlinear compensation and realize nonlinear compensation by an LSI.

Abstract translation: 提供了一种数字滤波器装置，包括用于执行输入数据的重新排列并输出重新排列的数据的数据重排装置，用于处理在特定时间输入的重排数据并产生中间数据的中间数据计算装置，用于计算第一输出的滤波器输出第一计算装置 通过使用中间数据在特定时间的值，延迟装置，用于通过处理在中间数据计算装置和文件输出第一计算装置中获取的时间来延迟重新排列的数据，以及滤波器输出第二计算装置，用于从延迟输入输出值 装置和滤波器输出第一计算装置，计算除特定时间之外的时间的第二输出值，并输出通过将第一和第二输出值相加而获得的滤波器输出值。 因此，在不损害用于非线性补偿的数字滤波器的性能的情况下减小电路规模并实现LSI的非线性补偿变得可行。

公开(公告)号：US20170207850A1

公开(公告)日：2017-07-20

申请号：US15327862

申请日：2015-07-17

Applicant: NEC Corporation

Inventor： Seigo TAKAHASHI ,  Toshiharu ITO ,  Kohei HOSOKAWA

IPC: H04B10/112 ,  H04B10/60

CPC classification number: H04B10/112 ,  H04B10/60

Abstract: The circuit size of a signal processing circuit increases in a free space optical receiver, which increases in cost, because the signal processing becomes complex attempting to improve the coupling efficiency between received light and a fiber; therefore, a free space optical receiver according to an exemplary aspect of the present invention includes a light collecting means for collecting laser light having propagated through a free space transmission path; a multi-mode transmission medium for receiving input of the laser light and outputting multi-mode light; a multi-mode signal processing means for outputting a plurality of received electrical signals based on part of the multi-mode light; a monitor means for monitoring signal information based on the multi-mode light; a control means for controlling an operation of the multi-mode signal processing means based on the signal information; and a signal processing means for performing signal processing on the plurality of received electrical signals and outputting an output signal synthesized from the plurality of received electrical signals.

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.

公开(公告)号：US20170264365A1

公开(公告)日：2017-09-14

申请号：US15529145

申请日：2015-11-18

Applicant: NEC Corporation

Inventor： Seigo TAKAHASHI ,  Toshiharu ITO ,  Akihiro TANAKA ,  Kohei HOSOKAWA ,  Manabu ARIKAWA

IPC: H04B10/118 ,  H04B10/548 ,  H04B10/112 ,  H04B10/2581 ,  H04B10/67

CPC classification number: H04B10/118 ,  H04B10/112 ,  H04B10/2581 ,  H04B10/548 ,  H04B10/676

Abstract: It is difficult in a free space optical receiver to satisfy both of the stable receiving and the highly sensitive receiving; therefore, a free space optical receiver according to an exemplary aspect of the present invention includes a light collecting means for collecting laser light having propagated through a free space transmission path; a multimode light generating means for receiving input of the laser light collected by the light collecting means, exciting multimode light, and outputting multimode propagation light including a plurality of propagation mode light beams with a number smaller than a number of multimode light beams possible to be excited; and a mode separating means for separating the multimode propagation light into the plurality of propagation mode light beams and outputting the plurality of propagation mode light beams.

公开(公告)号：US20220376811A1

公开(公告)日：2022-11-24

申请号：US17743695

申请日：2022-05-13

Applicant: NEC Corporation

Inventor： Keiichi MATSUMOTO ,  Kohei HOSOKAWA

IPC: H04J14/02 ,  H04B10/294

Abstract: A light amplification device according to an example aspect of the invention includes a wavelength demultiplexing unit configured to demultiplex the wavelength division multiplexed signal light into a plurality of wavelength bands; a plurality of light amplification media configured to amplify the plurality of pieces of demultiplexed multiplex signal light; a wavelength multiplexing unit configured to multiplex the amplified demultiplexed multiplex signal light; a plurality of excitation energy supply units configured to supply excitation energy to each of the plurality of light amplification media; and a control unit, wherein the control unit includes a wavelength multiplexing/demultiplexing control unit configured to control the wavelength demultiplexing unit and the wavelength multiplexing unit in such a way that a starting wavelength and a wavelength number become an optimum starting wavelength and an optimum wavelength number when a sum of power consumption of the plurality of excitation energy supply units is minimized.

公开(公告)号：US20180323904A1

公开(公告)日：2018-11-08

申请号：US15773035

申请日：2016-11-01

Applicant: NEC CORPORATION

Inventor： Kohei HOSOKAWA ,  Toshiharu ITO ,  Manabu ARIKAWA ,  Seigo TAKAHASHI ,  Takashi ISHIKAWA ,  Yoshimasa ONO

IPC: H04L1/00 ,  H04L27/22 ,  H04B10/61 ,  H04B10/118 ,  H04L27/00

CPC classification number: H04L1/0057 ,  H04B10/118 ,  H04B10/61 ,  H04L27/0014 ,  H04L27/22 ,  H04L2027/0057

Abstract: An appropriate synthesized signal cannot be obtained by only correcting relative phase errors of a plurality of received signals; therefore, a received signal processor according to an exemplary aspect of the present invention includes a plurality of signal-to-noise ratio estimation means for estimating respective signal-to-noise ratios of a plurality of digital signal sequences in which relative phase errors of a plurality of received signal sequences having been corrected; a plurality of temporary decision means for performing symbol decisions of the plurality of digital signal sequences and outputting symbol signal sequences; symbol-map-rotation determination means for determining respective phase rotation amounts of the plurality of digital signal sequences from the plurality of symbol signal sequences and the respective signal-to-noise ratios of the plurality of digital signal sequences; and a plurality of phase rotation means for rotating phases of the plurality of digital signal sequences respectively based on the phase rotation amounts.

公开(公告)号：US20150363360A1

公开(公告)日：2015-12-17

申请号：US14761995

申请日：2014-01-22

Applicant: NEC Corporation

Inventor： Atsufumi SHIBAYAMA ,  Kohei HOSOKAWA

IPC: G06F17/14 ,  H03H17/02

CPC classification number: G06F17/142 ,  H03H17/0213

Abstract: [Problem] A fast Fourier transform method is provided that are able to input data to be processed or output processing results in no particular order.[Solution] It is included to perform one of a process for rearranging, based on an output order setting, a plurality of output data generated by one of a fast Fourier transform and an inverse fast Fourier transform, and a process for rearranging, based on an input order setting, a plurality of input data into one of the fast Fourier transform and the inverse fast Fourier transform.

Abstract translation: [问题]提供能够以不特定顺序输入要处理的数据或输出处理结果的快速傅立叶变换方法。 [解决方案]基于输出顺序设置来执行由快速傅里叶变换和快速傅里叶逆变换之一生成的多个输出数据的重新排列处理中的一个，以及基于 输入顺序设置，多个输入数据转换为快速傅里叶变换和快速傅里叶逆变换之一。

公开(公告)号：US20200304213A1

公开(公告)日：2020-09-24

申请号：US16088328

申请日：2017-03-17

Applicant: NEC Corporation

Inventor： Kohei HOSOKAWA ,  Toshiharu ITO ,  Seigo TAKAHASHI ,  Manabu ARIKAWA ,  Takashi ISHIKAWA ,  Yoshimasa ONO

IPC: H04B10/69 ,  H04B10/11 ,  H04B17/336

Abstract: The objective of the present invention is to reduce the size of a receiving device circuit in an optical space communication system while maintaining communication stability. A data receiving device which decodes one item of data from a plurality of input signals includes: two or more digital signal processing means for subjecting the plurality of input signals to signal processing; a first recording means for temporarily recording the plurality of input signals; a SN ratio estimating means for estimating S/N ratios of each of the plurality of input signals and determining the number of the plurality of input signals to be combined, and the signals to be combined; and a scheduling means for carrying out overall control on the basis of the results from the SN ratio estimating means.

公开(公告)号：US20180234180A1

公开(公告)日：2018-08-16

申请号：US15751369

申请日：2016-08-17

Applicant: NEC CORPORATION

Inventor： Seigo TAKAHASHI ,  Toshiharu ITO ,  Kohei HOSOKAWA ,  Manabu ARIKAWA ,  Yoshimasa ONO ,  Takashi ISHIKAWA

IPC: H04B10/116 ,  H04B10/50 ,  H04B10/61

CPC classification number: H04B10/116 ,  H04B10/1121 ,  H04B10/118 ,  H04B10/50 ,  H04B10/61

Abstract: It is difficult in a free space optical transmitter to transmit a beacon beam stably at low cost, and that it is impossible to maintain stable tracking; therefore, a free space optical transmitter according to an exemplary aspect of the present invention includes a laser beam transmitting means for transmitting a plurality of laser beams capable of interfering with each other and differing in one of an optical frequency and a time variation in a phase difference; and a wavefront control beam transmitting means for transmitting, to a free space, a plurality of wavefront control beams obtained by making each of the plurality of laser beams have a different wavefront.

公开(公告)号：US20180212681A1

公开(公告)日：2018-07-26

申请号：US15745254

申请日：2016-07-15

Applicant: NEC CORPORATION

Inventor： Akihiro TANAKA ,  Toshiharu ITO ,  Kohei HOSOKAWA ,  Seigo TAKAHASHI ,  Manabu ARIKAWA

IPC: H04B10/118 ,  H04B10/00

CPC classification number: H04B10/118 ,  H04B10/112 ,  H04B10/12 ,  H04B10/40 ,  H04B10/50 ,  H04B10/60

Abstract: A receiving-side splitter 4 that constitutes part of an optical communication device 1 splits a receiving-side signal light into a plurality of lights at a splitting ratio according to the intensity distribution of mutually different propagation modes included in the receiving-side signal light passed through a transmission medium 3. A transmission-side splitter 10 splits a transmission-side signal light into a plurality of-lights. A signal processing device 5 detects the light intensity and/or the phase of the receiving-side signal light, and sets a control target value for the light intensity and/or the phase of the transmission-side signal light to a value according to the result of the detection. A modulator 9 adjusts the light intensity or the phase of a the transmission-side signal light so that the light intensity or phase equals the set value. A multiplexer 8 multiplexes the plurality of transmission-side signal lights.