Patents by Inventor Kenichi Takizawa

Kenichi Takizawa 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).

  • Publication number: 20240178886
    Abstract: A reception-side apparatus includes: M receive antennas; and a processor configured to execute a first process of acquiring a first signal received from a first transmission-side apparatus from among signals simultaneously received from the N transmission-side apparatuses by receive diversity processing, and acquiring first data by demodulating and decoding the first signal. In the case of N>M, the processor acquires, for each of all patterns of a combination of a first signal, second signals from M?1 transmission-side apparatuses which are to be cancelled by receive diversity processing and third signals from N?M transmission-side apparatuses which are not to be cancelled by the receive diversity processing, a power ratio of power of the first signal relative to total power of the second and third signals based on a predetermined weight and a channel estimate of each signal, and selects a combination with the largest power ratio from among all the patterns.
    Type: Application
    Filed: February 7, 2024
    Publication date: May 30, 2024
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Kenichi TAKIZAWA, Masafumi MORIYAMA, Fumihide KOJIMA, Atsushi KUROSAWA
  • Publication number: 20240171205
    Abstract: A wireless communication control method suppresses interference using an MMSE weight in an environment of wireless communication where the number of transmission stations transmitting a signal to a receiving station is larger than the number of reception antennas of the receiving station. The receiving station calculates power of an interference signal included in a signal received by the receiving station from the transmission stations the number of which is larger than the number of reception antennas, the interference signal corresponding to a part by which the number of transmission stations exceeds the number of reception antennas. The receiving station calculates the MMSE weight depending on the power of the interference signal, recalculates the power of the interference signal using the MMSE weight, and recalculates the MMSE weight depending on the recalculated power of the interference signal.
    Type: Application
    Filed: January 24, 2024
    Publication date: May 23, 2024
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Kenichi TAKIZAWA, Masafumi MORIYAMA, Fumihide KOJIMA, Atsushi KUROSAWA
  • Publication number: 20240146391
    Abstract: A communication system includes a first communication station, a second communication station, a relay station to non-regenerative-relay communications between the first communication station and the second communication station, and a control apparatus. The relay station relay-transmits a relay wave with a relay power value of such a limit as to fulfill a second condition when a transmission wave being transmitted from the first communication station and being relay-transmitted by the relay station fulfills a first condition about a signal-to-interference noise power ratio (SINR) and when the relay wave being relay-transmitted by the relay station and reaching the second communication station fulfills the second condition about the signal-to-interference noise power ratio (SINR) and the relay power value in the relay station.
    Type: Application
    Filed: November 1, 2023
    Publication date: May 2, 2024
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventor: Kenichi TAKIZAWA
  • Publication number: 20240147398
    Abstract: A base station includes the following parts: a propagation estimation part that estimates a radio wave propagation characteristic between a terminal and base station based on a training signal received from the terminal; a phase compensation part that compensates data to be transmitted to the terminal with phase rotation of a carrier wave that is indicated by the radio wave propagation characteristic; and a frequency conversion part that transmits the data that has been compensated by the phase compensation part to the terminal.
    Type: Application
    Filed: February 9, 2022
    Publication date: May 2, 2024
    Applicant: National Institute of Information and Communications Technology
    Inventors: Kenichi TAKIZAWA, Satoshi YASUDA, Nobuyasu SHIGA
  • Publication number: 20240147511
    Abstract: In a communication system that a relay station non-regeneratively relays a signal from a transmitting station to a first receiving station, when the relay station performs non-regenerative relay using a first resource block that is assigned to the relay station and the first receiving station for the non-regenerative relay and a second resource block that uses a baseband signal obtained by inverting the frequencies of a baseband signal relating to the first resource block, an information processing apparatus determines, based on information indicating a reception signal strength of a signal received by the relay station from a second receiving station other than the first receiving station, whether or not interference with the second receiving station is allowable, and assigns the second resource block to the relay station and the first receiving station as an additional resource block for the non-regenerative relay when the determining that the interference is allowable.
    Type: Application
    Filed: November 1, 2023
    Publication date: May 2, 2024
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventor: Kenichi TAKIZAWA
  • Publication number: 20240113770
    Abstract: A relay station includes a plurality of antennas and a controller. In non-regenerative relay of a first signal, the controller estimates an SINR of the first signal at a reception station after the relay on the basis of a transmit power of the first signal at a transmission station, first propagation characteristics between one or more first antennas set as reception antennas for the first signal and the transmission station, second propagation characteristics between one or more second antennas set as transmission antennas for the first signal after the relay and the reception station, a noise power and an interference power at the relay station, and a noise power at the reception station, and determines the first antennas and the second antennas in a combination that makes the SINR of the first signal at the reception station maximum respectively as the reception antennas and the transmission antennas.
    Type: Application
    Filed: September 26, 2023
    Publication date: April 4, 2024
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventor: Kenichi TAKIZAWA
  • Publication number: 20240106521
    Abstract: A communication system includes a first communication station, a second communication station, a relay station to relay a communication between the first communication station and the second communication station without changing a timeslot of the communication based on Time Division Multiplexing and a control apparatus. The control apparatus permits the relay station to perform a further communication in response to a communication request occurring in the relay station while relaying the communication, the further communication being directed to a third communication station when the communication to be relayed fulfill a first condition and when the further communication in response to the communication request fulfill a second condition.
    Type: Application
    Filed: September 27, 2023
    Publication date: March 28, 2024
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventor: Kenichi TAKIZAWA
  • Patent number: 11929795
    Abstract: A reception-side apparatus includes: M receive antennas; and a processor configured to execute a first process of acquiring a first signal received from a first transmission-side apparatus from among signals simultaneously received from the N transmission-side apparatuses by receive diversity processing, and acquiring first data by demodulating and decoding the first signal. In the case of N>M, the processor acquires, for each of all patterns of a combination of a first signal, second signals from M?1 transmission-side apparatuses which are to be cancelled by receive diversity processing and third signals from N?M transmission-side apparatuses which are not to be cancelled by the receive diversity processing, a power ratio of power of the first signal relative to total power of the second and third signals based on a predetermined weight and a channel estimate of each signal, and selects a combination with the largest power ratio from among all the patterns.
    Type: Grant
    Filed: December 22, 2022
    Date of Patent: March 12, 2024
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Kenichi Takizawa, Masafumi Moriyama, Fumihide Kojima, Atsushi Kurosawa
  • Patent number: 11916581
    Abstract: A wireless communication control method suppresses interference using an MMSE weight in an environment of wireless communication where the number of transmission stations transmitting a signal to a receiving station is larger than the number of reception antennas of the receiving station. The receiving station calculates power of an interference signal included in a signal received by the receiving station from the transmission stations the number of which is larger than the number of reception antennas, the interference signal corresponding to a part by which the number of transmission stations exceeds the number of reception antennas. The receiving station calculates the MMSE weight depending on the power of the interference signal, recalculates the power of the interference signal using the MMSE weight, and recalculates the MMSE weight depending on the recalculated power of the interference signal.
    Type: Grant
    Filed: December 12, 2022
    Date of Patent: February 27, 2024
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Kenichi Takizawa, Masafumi Moriyama, Fumihide Kojima, Atsushi Kurosawa
  • Publication number: 20240056126
    Abstract: A first relay station capable of performing, together with a second relay station, a non-replay relay for a first radio signal transmitted from a transmitting station for a receiving station having one antenna includes an antenna, a radio and a controller. The radio includes a receiver that converts the first radio signal into a baseband signal, an FIR filter that adds a delay to the baseband signal, and a transmitter that converts the signal output from the FIR filter into a second radio signal transmitted from the antenna to the receiving station. The controller ensures that the second radio signals transmitted from the respective antennas of the first and second relay stations have different delays, and that the FIR filter The delay is set in the FIR filter.
    Type: Application
    Filed: August 9, 2023
    Publication date: February 15, 2024
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventor: Kenichi TAKIZAWA
  • Publication number: 20240056165
    Abstract: A relay station comprises antennas, wireless devices corresponding to the antennas, and a controller to control an operation of the wireless devices. Each of the wireless devices includes a receiver to convert the first radio signal received by a corresponding antenna into a baseband signal, an FIR filter to assign a delay to the baseband signal; and a transmitter to convert a signal output from the FIR filter into a second radio signal transmitted from the corresponding antenna to the reception station. The controller sets a different delay amount in the FIR filter in each of the wireless devices so that the FIR filter assigns a delay, which is different from among the antennas, to the baseband signal input from the receiver in each of the wireless devices.
    Type: Application
    Filed: August 9, 2023
    Publication date: February 15, 2024
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventor: Kenichi TAKIZAWA
  • Publication number: 20240056937
    Abstract: A communication system includes a first communication station, one or more relay stations to be communicable with the first communication station, a second communication station to be communicable with the first communication station via any of the relay stations or without via any of the relay stations and a controller. The controller determines the relay station serving as an interposition in communications between the first communication station and the second communication station to maximize the communication path capacity between the first communication station and the second communication station under a predetermined constraint condition, the communication path capacity being calculated based on radio wave propagation characteristics between the first communication station and each of the relay stations, the characteristics between each of the relay stations and the second communication station, and the characteristics between the first communication station and the second communication station.
    Type: Application
    Filed: August 9, 2023
    Publication date: February 15, 2024
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventor: Kenichi TAKIZAWA
  • Publication number: 20240056163
    Abstract: A communication system includes a transmission station, a reception station, one or more relay stations configured to relay a first signal from the transmission station to the reception station without demodulating or decoding the first signal, and a controller. The controller is configured to acquire a first delay time and a first phase rotation amount to be provided to the first signal in relay by a first relay station so that one or more relay signals of the first signal arrive at the reception station at the same time and in the same phase after a first time length from a head of a slot in a radio frame and to cause the first relay station to provide the first delay time and the first phase rotation amount to the first signal.
    Type: Application
    Filed: August 8, 2023
    Publication date: February 15, 2024
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventor: Kenichi TAKIZAWA
  • Publication number: 20240014848
    Abstract: When signals are simultaneously received from K transmission-side apparatuses by a receiving antenna, and repetition is performed by the K transmission-side apparatuses, an information processing apparatus is configured to: in order to obtain a transmitted reference signal x(k,n) transmitted from a transmission-side apparatus k (k=1, . . . , K) by the n-th reference signal transmission in the repetition, acquire a phase rotation amount ?(g,n) given to a transmitted reference signal x(k) and assigned to a group g to which the transmission-side apparatus k belongs and transmit the phase rotation amount ?(g,n) to the transmission-side apparatus k. The phase rotation amount ?(g,n) is acquired so that received reference signals from transmission-side apparatuses not belonging to the group g are cancelled when a phase rotation amount opposite to the phase rotation amount ?(g,n) is given to a received reference signal r(n), and the first to N-th received reference signals in the repetition are added.
    Type: Application
    Filed: September 21, 2023
    Publication date: January 11, 2024
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Kenichi TAKIZAWA, Masafumi MORIYAMA
  • Patent number: 11864141
    Abstract: In performing wireless communication between terminals to perform time difference measurement and propagation time measurement, first and second terminals that transmit a signal at least once in attempting space-time synchronization are included. The first terminal measures a reception phase of a locally transmitted signal, and a reception phase of a signal transmitted by the second terminal, adds a positive or negative phase to the measured reception phase, and makes a report to the second terminal. The second terminal measures a reception phase of a locally transmitted signal, and a reception phase of a signal transmitted by the first terminal, and makes a report to the first terminal. The first and second terminals obtain a time difference or propagation time according to a reception phase measured by a local device and reported from a counterpart, and obtain additional information based on a phase reflected in the time difference or propagation time.
    Type: Grant
    Filed: November 29, 2021
    Date of Patent: January 2, 2024
    Assignee: NATIONAL INSTITUTE OF INFORMATION AND COMMUNICATIONS TECHNOLOGY
    Inventors: Maki Yoshida, Nobuyasu Shiga, Satoshi Yasuda, Kenichi Takizawa
  • Patent number: 11799512
    Abstract: When signals are simultaneously received from K transmission-side apparatuses by a receiving antenna, and repetition is performed by the K transmission-side apparatuses, an information processing apparatus is configured to: in order to obtain a transmitted reference signal x(k,n) transmitted from a transmission-side apparatus k (k=1, . . . , K) by the n-th reference signal transmission in the repetition, acquire a phase rotation amount ?(g,n) given to a transmitted reference signal x(k) and assigned to a group g to which the transmission-side apparatus k belongs and transmit the phase rotation amount ?(g,n) to the transmission-side apparatus k. The phase rotation amount ?(g,n) is acquired so that received reference signals from transmission-side apparatuses not belonging to the group g are cancelled when a phase rotation amount opposite to the phase rotation amount ?(g,n) is given to a received reference signal r(n), and the first to N-th received reference signals in the repetition are added.
    Type: Grant
    Filed: September 20, 2022
    Date of Patent: October 24, 2023
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Kenichi Takizawa, Masafumi Moriyama
  • Patent number: 11785613
    Abstract: A base station grants communications of a plurality of wireless communication terminals with the base station without allocating wireless resources upon occurrence of requests for the communications. The base station receives radio signals incoming from the wireless communication terminals and having encoded data, executes a first process of obtaining, from the received radio signals, first signals with at least ones of amplitudes and phases being adjusted, the first signals being incoming from a first wireless communication terminal among the plural wireless communication terminals, a second process of generating replicas of the radio signals incoming from the first wireless communication terminal before at least ones of the amplitudes and the phases are adjusted, a third process of extracting signals given by removing the replicas of the incoming radio signals from the received radio signals, and a process of iterating the first through third processes successively.
    Type: Grant
    Filed: October 11, 2021
    Date of Patent: October 10, 2023
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Kenichi Takizawa, Masafumi Moriyama, Fumihide Kojima, Atsushi Kurosawa
  • Publication number: 20230308124
    Abstract: The demodulating apparatus includes circuits of receiving modulated radio signals coming from a plurality of transmission devices, first demodulating a first reception signal DPSK-modulated among the radio signals, modulating demodulation signals into modulation signals based on DPSK, estimating an amplitude and a phase of a propagation signal on a propagation path leading to the reception circuit from the transmission device on the basis of the radio signal and the modulation signal, first generating, based on the variables, a first simulated signal simulating the first reception signal from the modulation signal, extracting a signal obtained by cancelling the first simulated signal from the radio signals, and repeating processes of the first demodulating, the modulating, the estimating, the first generating and the extracting to such a limit as to enable the first demodulating.
    Type: Application
    Filed: April 3, 2023
    Publication date: September 28, 2023
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Kenichi TAKIZAWA, Masafumi MORIYAMA, Fumihide KOJIMA, Atsushi KUROSAWA
  • Publication number: 20230171726
    Abstract: In performing wireless communication between terminals to perform time difference measurement and propagation time measurement, first and second terminals that transmit a signal at least once in attempting space-time synchronization are included. The first terminal measures a reception phase of a locally transmitted signal, and a reception phase of a signal transmitted by the second terminal, adds a positive or negative phase to the measured reception phase, and makes a report to the second terminal. The second terminal measures a reception phase of a locally transmitted signal, and a reception phase of a signal transmitted by the first terminal, and makes a report to the first terminal. The first and second terminals obtain a time difference or propagation time according to a reception phase measured by a local device and reported from a counterpart, and obtain additional information based on a phase reflected in the time difference or propagation time.
    Type: Application
    Filed: November 29, 2021
    Publication date: June 1, 2023
    Applicant: NATIONAL INSTITUTE OF INFORMATION AND COMMUNICATIONS TECHNOLOGY
    Inventors: Maki YOSHIDA, Nobuyasu SHIGA, Satoshi YASUDA, Kenichi TAKIZAWA
  • Patent number: 11664838
    Abstract: The demodulating apparatus includes circuits of receiving modulated radio signals coming from a plurality of transmission devices, first demodulating a first reception signal DPSK-modulated among the radio signals, modulating demodulation signals into modulation signals based on DPSK, estimating an amplitude and a phase of a propagation signal on a propagation path leading to the reception circuit from the transmission device on the basis of the radio signal and the modulation signal, first generating, based on the variables, a first simulated signal simulating the first reception signal from the modulation signal, extracting a signal obtained by cancelling the first simulated signal from the radio signals, and repeating processes of the first demodulating, the modulating, the estimating, the first generating and the extracting to such a limit as to enable the first demodulating.
    Type: Grant
    Filed: April 4, 2022
    Date of Patent: May 30, 2023
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Kenichi Takizawa, Masafumi Moriyama, Fumihide Kojima, Atsushi Kurosawa