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公开(公告)号：US12009868B2
公开(公告)日：2024-06-11
申请号：US17766296
申请日：2020-09-11
Applicant: NEC Corporation
Inventor： Manabu Arikawa
IPC: H04B10/61
CPC classification number: H04B10/612 , H04B10/6165
Abstract: In order to suppress wrong convergence of a filter coefficient without reducing data communication speed, this filter coefficient update amount output device is provided with: a first output unit which outputs a first coefficient update amount derived from a difference between a temporary determination result regarding a processed reception sample value that is the reception sample value on which filter processing by a digital filter has been performed and the processed reception sample value; a second output unit which outputs a second coefficient update amount derived from a gradient with respect to the filter coefficient such that the magnitude of a difference between statistical information on the processed reception sample value during some duration of time, and a set value regarding the statistical information is minimized; and a third output unit which outputs the coefficient update amount derived from the first coefficient update amount and the second coefficient update amount.
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公开(公告)号：US11300671B2
公开(公告)日：2022-04-12
申请号：US16472940
申请日：2016-12-26
Applicant: NEC Corporation
Inventor： Osamu Hoshuyama , Manabu Arikawa
Abstract: The present invention is a signal processing device that efficiently removes multiple types of interference waves mixed in with a received signal. This signal processing device is provided with: a first extraction unit that performs deconvolution with respect to a cross-correlation of a reference signal and a received signal and to an autocorrelation of the reference signal, and extracts a channel response to the reference signal; a second extraction unit that extracts a main channel response corresponding to the reference signal from the channel response; and a removal unit that restores a signal by performing convolution with respect to the reference signal and the main channel response, and removes the restored signal from the received signal.
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公开(公告)号：US11277758B2
公开(公告)日：2022-03-15
申请号：US16483083
申请日：2018-02-14
Applicant: NEC Corporation
Inventor： Yasunori Futatsugi , Toshiharu Ito , Manabu Arikawa
IPC: H04W24/02 , H04L1/08 , H04L12/26 , H04W40/12 , H04L43/0888
Abstract: It is difficult in related communication apparatuses to avoid degradation of communication quality due to fading and achieve sufficient throughput performance; therefore, a communication apparatus according to an exemplary aspect of the present invention includes fade avoidance rate calculation means for calculating, from a time variation in communication quality information and a transmission pattern in transmitting a communication packet repeatedly, a fade avoidance rate of a probability that the communication packet lies outside a fade duration, with respect to each transmission pattern; throughput calculation means for calculating, from the transmission pattern and the fade avoidance rate, a throughput of the communication packet with respect to each transmission pattern; and transmission pattern determination means for determining an optimum transmission pattern, of the transmission pattern, by which the throughput is maximized.
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公开(公告)号：US20250038858A1
公开(公告)日：2025-01-30
申请号：US18697049
申请日：2021-10-18
Applicant: NEC Corporation
Inventor： Masaki Sato , Manabu Arikawa
Abstract: A detector is configured to coherently receive a polarization-multiplexed optical signal transmitted from a transmitter via a transmission line. A digital signal processing circuit is configured to perform equalization signal processing on the reception signal coherently received. A carrier phase compensation filter is configured to compensate for a carrier phase in the reception signal. A 4×2 WL filter is disposed after the carrier phase compensation filter and configured to compensate for distortion included in the polarization-multiplexed optical signal. A filter coefficient updating unit is configured to update a filter coefficient of the carrier phase compensation filter and a filter coefficient of the 4×2 WL filter by use of an output of the 4×2 WL filter.
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公开(公告)号：US11728900B2
公开(公告)日：2023-08-15
申请号：US17726870
申请日：2022-04-22
Applicant: NEC Corporation
Inventor： Manabu Arikawa
CPC classification number: H04B10/6163 , H04B10/58 , H04L25/03057 , H04L25/03165
Abstract: A detector coherent-receives a signal being transmitted from a transmitter. A filter group includes a plurality of filters connected in series along a signal path of a reception signal. The plurality of filters include a plurality of non-linear distortion compensation filters and one or more linear distortion compensation filters. A coefficient updating unit controls a filter coefficient of the plurality of non-linear distortion compensation filters and a filter coefficient of at least some of the linear distortion compensation filters. The coefficient updating unit adaptively controls the filter coefficient, by using an error back propagation method, based on a difference between an output signal being output from the filter group and a predetermined value of the output signal.
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Patent Agency Ranking
公开(公告)号：US10313011B2
公开(公告)日：2019-06-04
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 , H04B10/112 , H04B10/2581 , H04B10/548 , H04B10/67
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.
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公开(公告)号：US11728888B2
公开(公告)日：2023-08-15
申请号：US17431504
申请日：2020-02-19
Applicant: NEC Corporation
Inventor： Manabu Arikawa , Toshiharu Ito
IPC: H04B10/11
CPC classification number: H04B10/11
Abstract: Tracking control of a light beam is achieved at high speed and with good precision, without requiring preparation of an optical system that causes high signal loss when coupling a reception light beam with an optical fiber. A reception device for optical space communication comprises: fibers having a plurality of propagation modes with spatially different characteristics; an optical coupling system for coupling the reception light beam to the fibers; and a mode separator that separates the coupled light into a plurality of propagation modes, the adjustment axes of the optical coupling system for coupling the reception light beam to one end of the fibers being controlled on the basis of the total coupling strength to all of the modes, and the priority of control of the axes being adjusted on the basis of information about the coupling strength ratio for each mode.
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公开(公告)号：US10511409B2
公开(公告)日：2019-12-17
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 , H04B10/118 , H04B10/61 , H04L27/00
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.
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9.发明授权公开(公告)号：US10361779B2
公开(公告)日：2019-07-23
申请号：US15559150
申请日：2016-03-17
Applicant: NEC Corporation
Inventor： Manabu Arikawa , Emmanuel Le Taillandier De Gabory , Toshiharu Ito
IPC: H04B10/079 , H04B10/077 , H04B10/2513 , H04B10/25 , H04B10/2581
Abstract: In the optical transmission system to transmit optical signals using a plurality of adjacent paths, it is difficult to detect a delay difference between a plurality of paths and chromatic dispersion with a high degree of accuracy due to a crosstalk; therefore, a method for detecting optical signal information according to an exemplary aspect of the present invention includes generating a plurality of data signal sequences corresponding to a plurality of paths multiplexed spatially, each of the plurality of data signal sequences obtained by inserting periodically a training signal with a plurality of frequency components in a data signal, in the plurality of data signal sequences, the training signals respectively included in the data signal sequences to be propagated through adjacent paths at least having different frequency components from each other at the same timing, each of a plurality of the training signals included in one of the data signal sequences having the plurality of frequency components whose frequency difference differing depending on a position to be inserted; and calculating a propagation delay difference between the plurality of paths and chromatic dispersion amounts in the plurality of paths from the plurality of frequency components included in the training signals having been propagated through the plurality of paths by optical signals.
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公开(公告)号：US09729229B2
公开(公告)日：2017-08-08
申请号：US14782831
申请日：2013-04-09
Applicant: NEC Corporation
Inventor： Emmanuel Le Taillandier De Gabory , Toshiharu Ito , Manabu Arikawa
IPC: H04B10/61 , H04J14/00 , H04B10/077 , H04J14/04 , H04L25/14 , H04B10/2581
CPC classification number: H04B10/0775 , H04B10/2581 , H04B10/611 , H04B10/615 , H04B10/6163 , H04B10/6164 , H04B10/6165 , H04J14/00 , H04J14/04 , H04L25/14
Abstract: The reception (102) reception unit includes; a first processing unit processing a first signal received from a source channel, and including a filtering unit to filter said first signal in digital domain, and extract unit to extract a information from said first signal; a second processing unit processing a second signal received from a destination channel, and said source channel and said destination channel are distinct each other; a third processing unit providing said information extracted from said first signal to said second signal said third processing unit executes; providing said information from said first processing unit to said second processing unit using information lanes of a clock rate strictly lower than a symbol rate of said second signal, a monitoring unit to generate a monitor signal according to the quality of said second signal; and a control unit controlling a skew between said first signal and said second signal in a bandwidth of said filtering units in said first processing unit.
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