Patents by Inventor Tsutomu TATSUTA

Tsutomu TATSUTA has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11979898
    Abstract: A wireless communication system includes a plurality of sets of base station devices and terminal station devices configured to perform communications in an equal frame length using a time division duplex scheme, the communications of the plurality of sets being simultaneously operated in adjacent areas, in which each of the base station devices includes a control unit configured to control a transmission timing of a downlink signal transmitted from the base station device itself based on a communication distance between the base station device and the terminal station device of each of the sets or a reception timing of a downlink signal in the terminal station device such that reception timings of downlink signals transmitted from the base station device itself and other base station devices in the terminal station devices of the sets fall within a predetermined range determined in advance.
    Type: Grant
    Filed: May 28, 2020
    Date of Patent: May 7, 2024
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Tomohiro Tokuyasu, Hiroyuki Furuya, Hayato Fukuzono, Yu Ono, Tsutomu Tatsuta, Tomohiro Nakayama
  • Patent number: 11968324
    Abstract: In a signal transmission system for transmitting an analog signal, in which a billing signal is superposed on an audio signal, from a transmitting device to a receiving device, the transmitting device includes a separation unit configured to separate the audio signal from the analog signal, an AD conversion unit configured to perform AD conversion on the audio signal separated by the separation unit, a detection unit configured to detect the billing signal from the analog signal, a coding unit configured to encode the billing signal detected by the detection unit, and a transmission unit configured to transmit the audio signal subjected to the AD conversion by the AD conversion unit and the billing signal encoded by the coding unit to the receiving device, and the receiving device includes a reception unit configured to receive the audio signal and the billing signal transmitted by the transmission unit, a DA conversion unit configured to perform DA conversion on the audio signal received by the reception uni
    Type: Grant
    Filed: July 27, 2020
    Date of Patent: April 23, 2024
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Hiroyuki Furuya, Tomohiro Tokuyasu, Hayato Fukuzono, Yu Ono, Tsutomu Tatsuta, Tomohiro Nakayama
  • Patent number: 11870517
    Abstract: According to the present invention, in a wireless communication system that performs single carrier MIMO transmission between a transmitting station device and a receiving station device, the transmitting station device includes a time-domain linear equalization unit, a propagation path characteristics estimation unit configured to receive a training signal and estimate a transfer function matrix of propagation path characteristics, a filter tap calculation unit configured to calculate filter tap coefficients for the time-domain linear equalization unit based on the transfer function matrix by a predefined approach, and a transmission mode determination unit configured to make the filter tap calculation unit calculate the filter tap coefficients when the transfer function matrix meets a predefined condition, and to change a transmission mode and determine the transmission mode that meets the predefined condition when the transfer function matrix does not meet the predefined condition.
    Type: Grant
    Filed: March 26, 2020
    Date of Patent: January 9, 2024
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Keita Kuriyama, Hayato Fukuzono, Masafumi Yoshioka, Tsutomu Tatsuta
  • Patent number: 11843429
    Abstract: According to the present invention, in a wireless communication system that performs single carrier MIMO transmission between a transmitting station device and a receiving station device, the transmitting station device including: a time-domain linear equalization unit configured to remove inter-symbol interference and inter-stream interference from a data signal to be transmitted to the receiving station device; a propagation path characteristics estimation unit configured to receive a training signal which is transmitted by the receiving station device and estimate a transfer function matrix of propagation path characteristics; and a filter tap calculation unit configured to calculate filter tap coefficients for the time-domain linear equalization unit by representing the estimated transfer function matrix as a matrix polynomial, taking an inverse response of the matrix polynomial as a transmit weight matrix, and approximating the transmit weight matrix with Neumann series, and the receiving station device
    Type: Grant
    Filed: March 26, 2020
    Date of Patent: December 12, 2023
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Keita Kuriyama, Hayato Fukuzono, Masafumi Yoshioka, Tsutomu Tatsuta
  • Patent number: 11838167
    Abstract: Provided is a wireless communication system configured to accommodate a plurality of circuits to transmit a signal from a transmitter to a receiver, the system including a number-of-circuits observation unit configured to observe the number of circuits among the plurality of circuits through which communication is being performed; a quality observation unit configured to observe a quality of each of a plurality of communications; a determination unit configured to determine a modulation scheme for transmitting a signal based on the number of circuits observed by the number-of-circuits observation unit, the quality of each of the plurality of communications observed by the quality observation unit, and a required throughput of each of the plurality of circuits; and a modulation unit configured to modulate the signal using the modulation scheme determined by the determination unit.
    Type: Grant
    Filed: May 28, 2020
    Date of Patent: December 5, 2023
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Hayato Fukuzono, Tomohiro Tokuyasu, Keita Kuriyama, Hiroyuki Furuya, Yu Ono, Tsutomu Tatsuta, Tomohiro Nakayama
  • Patent number: 11736168
    Abstract: A transmitting station device at least comprises a training signal generation unit, and a receiving station device at least comprises a communication path estimation unit which estimates a communication path response from the known signal, and a beam forming unit which performs a beam forming process using a weight to suppress inter-stream interference, a channel fluctuation amount calculation unit which calculates as a channel fluctuation amount a difference between the communication path responses estimated in a manner of one following another in time, and a weight calculation unit which calculates a new weight using an updated value of the weight calculated based on the channel fluctuation amount are included in one of the transmitting station device and the receiving station device. This can significantly reduce the amount of calculation related to update of a weight.
    Type: Grant
    Filed: September 6, 2019
    Date of Patent: August 22, 2023
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Keita Kuriyama, Hayato Fukuzono, Masafumi Yoshioka, Tsutomu Tatsuta
  • Patent number: 11677597
    Abstract: A wireless communication device includes an estimation observation unit that observes a channel condition by estimating a tendency of a long delay wave and a channel fluctuation from a received signal in which a training signal is added to a data frame, a first equalizer that compensates for the received signal, a second equalizer that compensates for the received signal with a property of having a higher long delay wave tolerance and a lower channel fluctuation tolerance than the first equalizer, and a control unit that performs control which switches such that the first equalizer or the second equalizer performs compensation for the received signal, on the basis of the channel condition observed by the estimation observation unit.
    Type: Grant
    Filed: May 21, 2019
    Date of Patent: June 13, 2023
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Hayato Fukuzono, Keita Kuriyama, Tomohiro Tokuyasu, Tsutomu Tatsuta
  • Patent number: 11646772
    Abstract: A transmitting station apparatus includes a training signal generation unit, a transmission end linear equalization unit configured to equalize data signals by a transmission end transfer function, and a transmitting station communication unit configured to transmit a training signal or a plurality of data signals and receive information of the transmission end transfer function from a receiving station apparatus.
    Type: Grant
    Filed: February 19, 2020
    Date of Patent: May 9, 2023
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Keita Kuriyama, Hayato Fukuzono, Tsutomu Tatsuta
  • Patent number: 11489557
    Abstract: In the present invention, a transmitting station apparatus includes a training signal generation unit, a transmission end linear equalization unit configured to output a plurality of second data signals obtained by equalizing IAI of a plurality of first data signals by using a transmission end transfer function for equalizing IAI, and a transmitting station communication unit configured to transmit a training signal or the plurality of second data signals to a receiving station apparatus and receive information on the transmission end transfer function from the receiving station apparatus, and the receiving station apparatus includes a communication path estimation unit configured to estimate a communication path response from the training signal received by the receiving station communication unit, a reception end coefficient calculation unit configured to calculate the transmission end transfer function and a reception end transfer function for equalizing ISI, based on the communication path response, and a
    Type: Grant
    Filed: February 19, 2020
    Date of Patent: November 1, 2022
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Keita Kuriyama, Hayato Fukuzono, Tsutomu Tatsuta
  • Publication number: 20220321392
    Abstract: Provided is a wireless communication system configured to accommodate a plurality of circuits to transmit a signal from a transmitter to a receiver, the system including a number-of-circuits observation unit configured to observe the number of circuits among the plurality of circuits through which communication is being performed; a quality observation unit configured to observe a quality of each of a plurality of communications; a determination unit configured to determine a modulation scheme for transmitting a signal based on the number of circuits observed by the number-of-circuits observation unit, the quality of each of the plurality of communications observed by the quality observation unit, and a required throughput of each of the plurality of circuits; and a modulation unit configured to modulate the signal using the modulation scheme determined by the determination unit.
    Type: Application
    Filed: May 28, 2020
    Publication date: October 6, 2022
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Hayato FUKUZONO, Tomohiro TOKUYASU, Keita KURIYAMA, Hiroyuki FURUYA, Yu ONO, Tsutomu TATSUTA, Tomohiro NAKAYAMA
  • Publication number: 20220302974
    Abstract: In a wireless communication system for performing single-carrier MIMO transmission, a transmitting station apparatus includes a training signal generation unit and a transmit beamforming unit that performs transmit beamforming processing using transmit weights and a receiving station apparatus includes a communication path estimation unit, an interference amount determination unit that determines whether or not a residual inter-stream interference exceeds a predetermined threshold value, a receive weight calculation unit that calculates a receive weight used for receive beamforming processing when the residual inter-stream interference exceeds the threshold value, and a receive beamforming unit that performs receive beamforming processing for suppressing residual inter-stream interferences using the receive weight.
    Type: Application
    Filed: August 20, 2019
    Publication date: September 22, 2022
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Keita KURIYAMA, Hayato FUKUZONO, Masafumi YOSHIOKA, Tsutomu TATSUTA
  • Publication number: 20220294506
    Abstract: A transmitting station device at least comprises a training signal generation unit, and a receiving station device at least comprises a communication path estimation unit which estimates a communication path response from the known signal, and a beam forming unit which performs a beam forming process using a weight to suppress inter-stream interference, a channel fluctuation amount calculation unit which calculates as a channel fluctuation amount a difference between the communication path responses estimated in a manner of one following another in time, and a weight calculation unit which calculates a new weight using an updated value of the weight calculated based on the channel fluctuation amount are included in one of the transmitting station device and the receiving station device. This can significantly reduce the amount of calculation related to update of a weight.
    Type: Application
    Filed: September 6, 2019
    Publication date: September 15, 2022
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Keita KURIYAMA, Hayato FUKUZONO, Masafumi YOSHIOKA, Tsutomu TATSUTA
  • Publication number: 20220278721
    Abstract: A transmission station device includes a training signal generation unit, a CP addition unit, and a transmission beamforming unit that performs transmission beamforming processing in a time domain using a transmission weight for removing inter-antenna interference. A reception station device includes a CP removal unit, a channel estimation unit, and an equalization unit that performs equalization processing for removing inter-symbol interference in a frequency domain using a reception weight. Either of the transmission station device or the reception station device is provided with a weight calculation unit that calculates the transmission weight and the reception weight based on the channel response, an effective CIR length calculation unit that calculates an effective CIR length between antennas, and a CP length setting unit that sets, to the CP length, a maximum CIR length among the CIR lengths of respective items of the reception weight.
    Type: Application
    Filed: August 21, 2019
    Publication date: September 1, 2022
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Hayato FUKUZONO, Keita KURIYAMA, Masafumi YOSHIOKA, Tsutomu TATSUTA
  • Publication number: 20220279368
    Abstract: A wireless base station device includes a test request unit that, upon receipt of a line test request from a host station side, transmits an implementation request for a line test to a wireless terminal station device and a test response unit that transmits at least one of a terminal identification code returned from the wireless terminal station device and a terminal identification code and a line test result of the wireless base station device to the host station side.
    Type: Application
    Filed: June 26, 2020
    Publication date: September 1, 2022
    Inventors: Yu ONO, Tomohiro TOKUYASU, Hiroyuki FURUYA, Hayato FUKUZONO, Tsutomu TATSUTA, Tomohiro NAKAYAMA
  • Publication number: 20220263948
    Abstract: In a signal transmission system for transmitting an analog signal, in which a billing signal is superposed on an audio signal, from a transmitting device to a receiving device, the transmitting device includes a separation unit configured to separate the audio signal from the analog signal, an AD conversion unit configured to perform AD conversion on the audio signal separated by the separation unit, a detection unit configured to detect the billing signal from the analog signal, a coding unit configured to encode the billing signal detected by the detection unit, and a transmission unit configured to transmit the audio signal subjected to the AD conversion by the AD conversion unit and the billing signal encoded by the coding unit to the receiving device, and the receiving device includes a reception unit configured to receive the audio signal and the billing signal transmitted by the transmission unit, a DA conversion unit configured to perform DA conversion on the audio signal received by the reception uni
    Type: Application
    Filed: July 27, 2020
    Publication date: August 18, 2022
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Hiroyuki FURUYA, Tomohiro TOKUYASU, Hayato FUKUZONO, Yu ONO, Tsutomu TATSUTA, Tomohiro NAKAYAMA
  • Publication number: 20220240272
    Abstract: A wireless communication system includes a plurality of sets of base station devices and terminal station devices configured to perform communications in an equal frame length using a time division duplex scheme, the communications of the plurality of sets being simultaneously operated in adjacent areas, in which each of the base station devices includes a control unit configured to control a transmission timing of a downlink signal transmitted from the base station device itself based on a communication distance between the base station device and the terminal station device of each of the sets or a reception timing of a downlink signal in the terminal station device such that reception timings of downlink signals transmitted from the base station device itself and other base station devices in the terminal station devices of the sets fall within a predetermined range determined in advance.
    Type: Application
    Filed: May 28, 2020
    Publication date: July 28, 2022
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Tomohiro TOKUYASU, Hiroyuki FURUYA, Hayato FUKUZONO, Yu ONO, Tsutomu TATSUTA, Tomohiro NAKAYAMA
  • Publication number: 20220216900
    Abstract: According to the present invention, in a wireless communication system that performs single carrier MIMO transmission between a transmitting station device and a receiving station device, the transmitting station device includes a time-domain linear equalization unit, a propagation path characteristics estimation unit configured to receive a training signal and estimate a transfer function matrix of propagation path characteristics, a filter tap calculation unit configured to calculate filter tap coefficients for the time-domain linear equalization unit based on the transfer function matrix by a predefined approach, and a transmission mode determination unit configured to make the filter tap calculation unit calculate the filter tap coefficients when the transfer function matrix meets a predefined condition, and to change a transmission mode and determine the transmission mode that meets the predefined condition when the transfer function matrix does not meet the predefined condition.
    Type: Application
    Filed: March 26, 2020
    Publication date: July 7, 2022
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Keita KURIYAMA, Hayato FUKUZONO, Masafumi YOSHIOKA, Tsutomu TATSUTA
  • Publication number: 20220209830
    Abstract: According to the present invention, in a wireless communication system that performs single carrier MIMO transmission between a transmitting station device and a receiving station device, the transmitting station device including: a time-domain linear equalization unit configured to remove inter-symbol interference and inter-stream interference from a data signal to be transmitted to the receiving station device; a propagation path characteristics estimation unit configured to receive a training signal which is transmitted by the receiving station device and estimate a transfer function matrix of propagation path characteristics; and a filter tap calculation unit configured to calculate filter tap coefficients for the time-domain linear equalization unit by representing the estimated transfer function matrix as a matrix polynomial, taking an inverse response of the matrix polynomial as a transmit weight matrix, and approximating the transmit weight matrix with Neumann series, and the receiving station device
    Type: Application
    Filed: March 26, 2020
    Publication date: June 30, 2022
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Keita KURIYAMA, Hayato FUKUZONO, Masafumi YOSHIOKA, Tsutomu TATSUTA
  • Publication number: 20220200830
    Abstract: A wireless communication device includes an estimation observation unit that observes a channel condition by estimating a tendency of a long delay wave and a channel fluctuation from a received signal in which a training signal is added to a data frame, a first equalizer that compensates for the received signal, a second equalizer that compensates for the received signal with a property of having a higher long delay wave tolerance and a lower channel fluctuation tolerance than the first equalizer, and a control unit that performs control which switches such that the first equalizer or the second equalizer performs compensation for the received signal, on the basis of the channel condition observed by the estimation observation unit.
    Type: Application
    Filed: May 21, 2019
    Publication date: June 23, 2022
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Hayato FUKUZONO, Keita KURIYAMA, Tomoniro TOKUYASU, Tsutomu TATSUTA
  • Publication number: 20220149898
    Abstract: In the present invention, a transmitting station apparatus includes a training signal generation unit, a transmission end linear equalization unit configured to output a plurality of second data signals obtained by equalizing IAI of a plurality of first data signals by using a transmission end transfer function for equalizing IAI, and a transmitting station communication unit configured to transmit a training signal or the plurality of second data signals to a receiving station apparatus and receive information on the transmission end transfer function from the receiving station apparatus, and the receiving station apparatus includes a communication path estimation unit configured to estimate a communication path response from the training signal received by the receiving station communication unit, a reception end coefficient calculation unit configured to calculate the transmission end transfer function and a reception end transfer function for equalizing ISI, based on the communication path response, and a
    Type: Application
    Filed: February 19, 2020
    Publication date: May 12, 2022
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Keita KURIYAMA, Hayato FUKUZONO, Tsutomu TATSUTA