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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.
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公开(公告)号：US20170373704A1
公开(公告)日：2017-12-28
申请号：US15544299
申请日：2016-01-20
Applicant: NEC Corporation
Inventor： Tatsuya NAKAMURA , Emmanuel LE TAILLANDIER DE GABORY , Junichi ABE
IPC: H03M13/23 , H04B10/516 , H04J11/00
CPC classification number: H03M13/23 , H03M13/256 , H04B10/516 , H04J11/00
Abstract: If a configuration is employed in which modulation schemes used for an optical communication system can be switched depending on transmission conditions, it is difficult to make effective utilization of frequency resources without the power consumption increasing and the control becoming complex; therefore, an optical transmitter according to an exemplary aspect of the present invention includes an interface means for converting a digital signal to be transmitted under a predetermined transmission condition over an optical carrier wave into a parallel signal with a predetermined bit number at a predetermined transmission rate, and outputting the parallel signal; an encoding means for encoding the parallel signal using one coding system from among a plurality of convolutional coding systems with different degrees of redundancy; a mapping means for mapping an output bit signal output from the encoding means to a modulation symbol; an optical modulation means for modulating the optical carrier wave based on a symbol signal output from the mapping means; and an encoding control means for selecting a predetermined coding system corresponding to the predetermined transmission condition from among the plurality of convolutional coding systems and controlling the interface means, the encoding means, the mapping means, and the optical modulation means in such a way as to operate in accordance with the predetermined coding system.
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公开(公告)号：US20190296829A1
公开(公告)日：2019-09-26
申请号：US16438161
申请日：2019-06-11
Applicant: NEC Corporation
Inventor： Junichi ABE , Tatsuya NAKAMURA
IPC: H04B10/516 , H04B10/25 , 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.
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Patent Agency Ranking
公开(公告)号：US20210288721A1
公开(公告)日：2021-09-16
申请号：US16338733
申请日：2017-08-25
Applicant: NEC Corporation
Inventor： Tatsuya NAKAMURA , Junichi ABE
Abstract: A receiving unit (2020) generates a received frame from a modulated optical signal. The modulated optical signal is generated such that a transmission symbol is generated by mapping an encoded bit string obtained by encoding a transmission bit string to an m-dimensional symbol space, a transmission frame is generated by mapping the transmission symbol to an n-dimensional frame space (n
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公开(公告)号：US20210135760A1
公开(公告)日：2021-05-06
申请号：US17148829
申请日：2021-01-14
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.
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公开(公告)号：US20190081645A1
公开(公告)日：2019-03-14
申请号：US16084807
申请日：2017-04-14
Applicant: NEC Corporation
Inventor： Tatsuya NAKAMURA , Junichi ABE
Abstract: An optical transmission apparatus (100) generates a second bit sequence B by encoding a first bit sequence b having forward error correction coding performed on a transmission bit sequence, maps the second bit sequence to a transmission symbol signal, and transmits an optical modulated signal generated by modulating an optical carrier wave into the transmission symbol signal. A symbol output unit (2020) generates a received symbol signal by demodulating an optical modulated signal received by an optical reception apparatus (2000). A first computation unit (2040) computes LLR(Bi) which is a log-likelihood ratio (LLR) of each bit Bi of the second bit sequence, using the received symbol signal. A second computation unit (2060) computes a log-likelihood ratio LLR(bi) of each bit bi of the first bit sequence from the LLR(Bi). A correspondence relationship between each bit of the first bit sequence and each bit of the second bit sequence is used in this computation. A decoding unit (2080) decodes the transmission bit sequence using the LLR(bi).
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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.
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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.
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