Patents Assigned to NTT Electronics Corporation
  • Patent number: 11494165
    Abstract: An arithmetic circuit includes a LUT generation circuit (1) that, when coefficients c[n] (n=1, . . . , N) are paired two by two, outputs a value calculated for each of the pairs, and distributed arithmetic circuits (2-m) that calculate values z[m] that are sums of products of data x[m, n] of a data set X[m] containing M pairs of data x[m, n] and the coefficients c[n], in parallel for each of the M pairs. The distributed arithmetic circuit (2-m) includes binomial distributed arithmetic circuits that, for each of the pairs, calculate sums of products of a value obtained by pairing N data x[m, n] corresponding to the circuit two by two and a value obtained by pairing the coefficients c[n] two by two, and a figure matching circuit that matches a number of decimal figures of the sums with a predetermined number of decimal figures.
    Type: Grant
    Filed: December 18, 2018
    Date of Patent: November 8, 2022
    Assignees: NTT ELECTRONICS CORPORATION, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Kenji Kawai, Ryo Awata, Kazuhito Takei, Masaaki Iizuka
  • Patent number: 11432005
    Abstract: A computation unit subtracts a prediction image from an input image. An orthogonal transformation unit applies orthogonal transformation to an output of the computation unit. A quantization unit quantizes an output of the orthogonal transformation unit. An encoding unit encodes an output of the quantization unit. A prediction mode determination unit determines a prediction mode from the input image. The prediction mode is different according to types of an I-picture, a P-picture and a B-picture.
    Type: Grant
    Filed: June 25, 2019
    Date of Patent: August 30, 2022
    Assignees: NTT ELECTRONICS CORPORATION, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Akiko Shimazaki, Ken Nakamura, Takayuki Onishi, Takashi Sano
  • Patent number: 11360741
    Abstract: An arithmetic circuit includes an LUT generation circuit (1) that, when coefficients c[n] (n=1, . . . , N) are paired two by two, outputs a value calculated for each of the pairs, and a distributed arithmetic circuit (2-m) that calculates values y[m] of product-sum arithmetic, by which data x[m, n] of a data set X[m] containing M pairs of data x[m, n] is multiplied by the coefficients c[n] and the products are summed up, in parallel for each of the M pairs.
    Type: Grant
    Filed: December 18, 2018
    Date of Patent: June 14, 2022
    Assignees: NTT ELECTRONICS CORPORATION, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Kenji Kawai, Ryo Awata, Kazuhito Takei, Masaaki Iizuka
  • Publication number: 20220173807
    Abstract: Part of compensation of the transmission characteristics of the optical transmitter is performed by transmitter compensation circuitry disposed at a stage prior to the optical transmitter. Remaining part of compensation of the transmission characteristics of the optical transmitter and compensation of the transmission characteristics of the optical receiver is performed by a receiver compensation circuitry disposed at a stage subsequent to the optical receiver. Transmitter compensation characteristics of the transmitter compensation circuitry is set so that a peak-to-average-power ratio of an output signal from the transmitter compensation circuitry becomes equal to or smaller than a predetermined value.
    Type: Application
    Filed: May 21, 2020
    Publication date: June 2, 2022
    Applicants: NTT Electronics Corporation, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Akihiro YAMAGISHI, Atsushi HOKI, Katsuya TANAKA, Eisuke TSUCHIYA, Masanori NAKAMURA, Asuka MATSUSHITA
  • Patent number: 11333950
    Abstract: An optical module of a configuration that ensures use of commercially available electronic components and reduction of the number of current generation circuits and electric wirings. The optical module includes an electronic component mounted on a separate board from a light wave circuit board provided with an optical component such as an optical switch, and they are each electrically connected by wire bonding. For this reason, the optical module can use a commercially available electronic component. In addition, the module has a configuration in which heaters of optical switches, which do not simultaneously flow currents, are grouped and a current from one current generation circuit is supplied to any one of the heaters in the group by means of one electrical switch. For this reason, the optical module does not have to be prepared with the same number of electrical switches and current generation circuits as the number of heaters.
    Type: Grant
    Filed: August 30, 2019
    Date of Patent: May 17, 2022
    Assignee: NTT ELECTRONICS CORPORATION
    Inventors: Atsushi Kusayama, Yasuyuki Nanaumi, Kiyoshi Kido, Yuji Akahori
  • Patent number: 11329764
    Abstract: An error correction device includes a first correction unit which performs error correction decoding of data by a repetitive operation, having a full operation state in which the error correction decoding is repeated until convergence is obtained and a save operation state in which the number of times of the repetitive operation is restricted to a predetermined number. An error information estimation unit estimates an input error rate or an output error rate of the first correction unit using a decoding result of the first correction unit, and a control unit which controls transition between the full operation state and the save operation state based on at least one piece of information of the input error rate, the output error rate, and an operation time of the first correction unit. It is thus possible to provide an error correction device that can improve a transmission characteristic while suppressing power consumption.
    Type: Grant
    Filed: December 20, 2018
    Date of Patent: May 10, 2022
    Assignees: NTT ELECTRONICS CORPORATION, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Fumiaki Nakagawa, Yasuharu Onuma, Katsuichi Oyama, Yasuyuki Endoh, Etsushi Yamazaki, Yoshiaki Kisaka, Masahito Tomizawa
  • Patent number: 11323238
    Abstract: A frame synchronization apparatus (10) according to this invention includes a multiplication unit (11) configured to multiply a received signal by an inverse complex number of a predetermined synchronization pattern with respect to a predetermined signal point on a complex space diagram for each of a plurality of symbols of the received signal, an addition average unit (12) configured to perform addition averaging of outputs from the multiplication unit for the plurality of symbols of the received signal, and a synchronization determination unit (13) configured to perform coincidence determination of whether an output from the addition average unit (12) falls within a predetermined coincidence determination range of the predetermined signal point, and determine a synchronization state of the frame synchronization based on a result of the coincidence determination.
    Type: Grant
    Filed: June 6, 2019
    Date of Patent: May 3, 2022
    Assignees: NTT ELECTRONICS CORPORATION, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Mitsuteru Yoshida, Yasuyuki Endoh, Katsuichi Oyama, Masayuki Ikeda, Tsutomu Takeya, Etsushi Yamazaki, Yoshiaki Kisaka, Masahito Tomizawa
  • Patent number: 11307356
    Abstract: An optical module that has a structure ensuring reduction in size. The optical module has a structure where a part of a fiber block is protruded from a housing. By including a thin plate, this optical module can avoid entering of dust in the housing, allows a position shift of the fiber block due to a mounting position error of an optical component in the housing, a position shift of an opening portion due to a dimensional error of the housing, or a displacement due to a temperature change, and can reduce the coupling loss due to the optical axis misalignment.
    Type: Grant
    Filed: December 19, 2018
    Date of Patent: April 19, 2022
    Assignees: NTT ELECTRONICS CORPORATION, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Yuichi Suzuki, Tomohiro Nakanishi, Motoki Minami, Hiroshi Tomita, Motohaya Ishii, Shuichiro Asakawa, Shunichi Soma
  • Patent number: 11287578
    Abstract: There is provided a small MCS with the number of leads reduced by half as compared with the conventional configuration. A multicast switch according to the present invention is formed on a substrate, comprising: M input ports, N output ports; M×N optical switch units (optical SU); optical waveguides optically connecting the M input ports, M×N optical SU, and N output ports; and leads connected to the respective M×N optical SU. A multicast switch is configured such that by activating one optical SU, an optical signal input to an input port associated with the activated optical SU is output from an output port associated with the activated optical SU. The M×N optical SU include at least a gate switch and a main switch. In each optical SU, the gate switch and the main switch are connected to the common lead.
    Type: Grant
    Filed: March 26, 2019
    Date of Patent: March 29, 2022
    Assignee: NTT ELECTRONICS CORPORATION
    Inventors: Mitsuru Nagano, Tatsuya Yoshii, Masahiro Yanagisawa, Tatsunori Nakahashi
  • Patent number: 11228366
    Abstract: A process of estimating a transfer function or an inverse transfer function of the optical transmitter from first data obtained by the optical receiver when a first known signal is transmitted from the transmitter to the receiver, and a temporary transfer function or a temporary inverse transfer function of the optical receiver, is performed for multiple frequency offsets between the optical transmitter and the optical receiver. At this time, the transfer function or the inverse transfer function of the optical transmitter is estimated by comparing the first data obtained by compensating at least one or none of a temporary transfer function of the optical receiver and transmission path characteristics detected in the receiver, with a first known signal before transmission to which what is not compensated for the first data between the temporary transfer function of the optical receiver and the transmission path characteristic is added.
    Type: Grant
    Filed: February 3, 2020
    Date of Patent: January 18, 2022
    Assignees: NTT ELECTRONICS CORPORATION, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Akihiro Yamagishi, Atsushi Hoki, Masayuki Sugasawa, Masanori Nakamura, Asuka Matsushita
  • Patent number: 11217705
    Abstract: A semiconductor element capable of adjusting a barrier height ?Bn and performing zero-bias operation and impedance matching with an antenna for improving detection sensitivity of high-frequency RF electric signals, a method of manufacturing the same, and a semiconductor device having the same. In the semiconductor element, a concentration of InGaAs (n-type InGaAs layer) is intentionally set to be high over a range for preventing the “change of the barrier height caused by the bias” described above up to a deep degeneration range. An electron Fermi level (EF) increases from a band edge of InGaAs (n-type InGaAs layer) to a band edge of InP (InP depletion layer).
    Type: Grant
    Filed: June 6, 2019
    Date of Patent: January 4, 2022
    Assignee: NTT ELECTRONICS CORPORATION
    Inventors: Makoto Shimizu, Hiroki Itoh, Tadao Ishibashi, Isamu Kotaka
  • Patent number: 11201721
    Abstract: A frame synchronization apparatus (10) according to this invention includes a multiplication unit (11) configured to multiply a received signal by an inverse complex number of a predetermined synchronization pattern with respect to a predetermined signal point on a complex space diagram for each of a plurality of symbols of the received signal, an addition average unit (12) configured to perform addition averaging of outputs from the multiplication unit for the plurality of symbols of the received signal, and a synchronization determination unit (13) configured to perform coincidence determination of whether an output from the addition average unit (12) falls within a predetermined coincidence determination range of the predetermined signal point, and determine a synchronization state of the frame synchronization based on a result of the coincidence determination.
    Type: Grant
    Filed: February 12, 2021
    Date of Patent: December 14, 2021
    Assignees: NTT ELECTRONICS CORPORATION, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Mitsuteru Yoshida, Yasuyuki Endoh, Katsuichi Oyama, Masayuki Ikeda, Tsutomu Takeya, Etsushi Yamazaki, Yoshiaki Kisaka, Masahito Tomizawa
  • Publication number: 20210344424
    Abstract: First compensation circuitry includes a first digital filter compensating a phase difference between a phase of a symbol of a received signal and a sampling timing, and first filter coefficient calculation circuitry calculating a filter coefficient of the first digital filter as a first filter coefficient. Second filter coefficient calculation circuitry calculates, as a second filter coefficient, a filter coefficient for adaptive equalization that compensates distortion due to temporally changing polarization dispersion, based on an output of the first digital filter. Coefficient combination circuitry combines the first filter coefficient and the second filter coefficient. Second compensation circuitry includes a second digital filter which uses a filter coefficient combined by the coefficient combination circuitry and performs a compensation of the phase difference between the phase of the symbol of the received signal and the sampling timing, and a process of the adaptive equalization at the same time.
    Type: Application
    Filed: October 7, 2019
    Publication date: November 4, 2021
    Applicant: NTT Electronics Corporation
    Inventors: Tomohiro TAKAMUKU, Mitsuteru YOSHIDA, Tsutomu TAKEYA, Kazuhito TAKEI, Katsuichi OYAMA, Tomoharu SEMBOKU
  • Publication number: 20210328666
    Abstract: A process of estimating a transfer function or an inverse transfer function of the optical transmitter from first data obtained by the optical receiver when a first known signal is transmitted from the transmitter to the receiver, and a temporary transfer function or a temporary inverse transfer function of the optical receiver, is performed for multiple frequency offsets between the optical transmitter and the optical receiver. At this time, the transfer function or the inverse transfer function of the optical transmitter is estimated by comparing the first data obtained by compensating at least one or none of a temporary transfer function of the optical receiver and transmission path characteristics detected in the receiver, with a first known signal before transmission to which what is not compensated for the first data between the temporary transfer function of the optical receiver and the transmission path characteristic is added.
    Type: Application
    Filed: February 3, 2020
    Publication date: October 21, 2021
    Applicants: NTT Electronics Corporation, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Akihiro YAMAGISHI, Atsushi HOKI, Masayuki SUGASAWA, Masanori NAKAMURA, Asuka MATSUSHITA
  • Patent number: 11134249
    Abstract: A binary arithmetic device includes an LPS/MPS determining unit that determines, using a context variable, a range length, and an offset, whether a code is an inferior probability code or a superior probability code, a renormalization processing unit that performs renormalization processing on the range length and the offset, and a context-variable calculating unit that derives the binary data of the code using a determination result and updates the context variable according to the determination result. The renormalization processing unit 15 includes a first renormalizing unit and a second renormalizing unit and a selecting unit that selects, according to the determination result, an output of the first renormalizing unit or an output of the second renormalizing unit.
    Type: Grant
    Filed: March 14, 2018
    Date of Patent: September 28, 2021
    Assignee: NTT Electronics Corporation
    Inventors: Manabu Tagaki, Takashi Matsumoto
  • Patent number: 11121778
    Abstract: A known pattern comparison type phase difference detection unit (12) detects a phase difference between a known pattern extracted from a received signal and a true value of the known pattern as a first phase difference. M indicates the number of modulation phases in a phase modulation method of the received signal. An M-th power type phase difference detection unit (13) removes a modulation component by raising the received signal to M-th power, and detects phase variation from a modulation phase point used for mapping on a transmission side, as a second phase difference. A phase compensation unit (11) compensates phase variation of the received signal based on an addition result of the first phase difference and the second phase difference.
    Type: Grant
    Filed: July 22, 2019
    Date of Patent: September 14, 2021
    Assignees: NTT ELECTRONICS CORPORATION, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Tomohiro Takamuku, Mitsuteru Yoshida, Tsutomu Takeya, Katsuichi Oyama, Hiroyuki Nouchi, Atsushi Suenaga
  • Publication number: 20210273732
    Abstract: A known pattern comparison type phase difference detection unit (12) detects a phase difference between a known pattern extracted from a received signal and a true value of the known pattern as a first phase difference. M indicates the number of modulation phases in a phase modulation method of the received signal. An M-th power type phase difference detection unit (13) removes a modulation component by raising the received signal to M-th power, and detects phase variation from a modulation phase point used for mapping on a transmission side, as a second phase difference. A phase compensation unit (11) compensates phase variation of the received signal based on an addition result of the first phase difference and the second phase difference.
    Type: Application
    Filed: July 22, 2019
    Publication date: September 2, 2021
    Applicant: NTT Electronics Corporation
    Inventors: Tomohiro TAKAMUKU, Mitsuteru YOSHIDA, Tsutomu TAKEYA, Katsuichi OYAMA, Hiroyuki NOUCHI, Atsushi SUENAGA
  • Patent number: 10983274
    Abstract: A broadband optical wavelength multiplexer/demultiplexer is provided. Two waveguides are arranged such that, in a case where a connection position where one of the two waveguides is connected to a first slab waveguide is set closer to the other waveguide by a channel frequency interval ?f, a central position between the two waveguides aligns with a central position on a connection end surface of the first slab waveguide, and two waveguide groups of an output waveguide are arranged such that a central position between the two waveguide groups aligns with a central position of a second slab waveguide, and an interval between a connection position where the other waveguide is connected to the first slab waveguide and the central position on the connection end surface of the first slab waveguide is set equal to an interval between a connection position where the waveguide groups are connected to the second slab waveguide.
    Type: Grant
    Filed: November 21, 2018
    Date of Patent: April 20, 2021
    Assignee: NTT ELECTRONICS CORPORATION
    Inventors: Daisuke Ogawa, Youichi Nishizato
  • Patent number: 10908356
    Abstract: An optical circuit board which is mounted with a loop-back circuit for returning aligning light to the fiber array in the vicinity of the fiber array connection end. Since an aligning loop-back circuit can be formed in an optical waveguide pattern, a production cost does not increase in comparison to an optical circuit board of the related art. The aligning light combined from the optical fiber to the aligning port of the optical circuit board is returned to the optical fiber around the loop-back circuit. Therefore, it is possible to perform alignment using the returned light. That is, alignment can be performed while being mounted on a package without installing a light-reflecting film or mirror.
    Type: Grant
    Filed: November 2, 2017
    Date of Patent: February 2, 2021
    Assignees: NTT ELECTRONICS CORPORATION, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Tomohiro Nakanishi, Motoki Minami, Satoru Konno, Yuichi Suzuki, Teruaki Sato, Shigeo Nagashima, Shinji Mino, Motohaya Ishii, Shunichi Soma, Shin Kamei, Shuichiro Asakawa
  • Patent number: 10880193
    Abstract: A plurality of error correction circuits corrects errors of the data transmitted through the plurality of transmission lines. A combining portion combines the plurality of transmission lines to the plurality of error correction circuits. The plurality of transmission lines includes a first transmission line, and a second transmission line having a lower transmission characteristic than the first transmission line. The plurality of error correction circuits includes a first and a second error correction circuit having lower error correction capability and power consumption than the first error correction circuit. The combining portion uses a function to combine a plurality of error correction circuits with one transmission path, combines the first transmission line with the second error correction circuit at a higher rate than the first error correction circuit, and combines the second transmission line with the first error correction circuit at a higher rate than the second error correction circuit.
    Type: Grant
    Filed: December 15, 2017
    Date of Patent: December 29, 2020
    Assignees: NTT ELECTRONICS CORPORATION, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Mitsuteru Yoshida, Yasuyuki Endo, Etsushi Yamazaki, Katsuichi Oyama, Yasuharu Onuma, Masahito Tomizawa