Patents by Inventor Tomonori Yamamoto

Tomonori Yamamoto 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: 8964777
    Abstract: In a radio communication system where a base station provides blank time slots to avoid inter-cell interference, a decrease in throughput by an excess or shortage of blank time slots is prevented. This invention relates to a radio system that avoids interference in cooperation between base stations by providing blank time slots by a (first) base station. Other (second) base stations detect the number of served terminals affected by interference from the first base station that sets blank time slots, calculate required blank time slots so that the number of required blank time slots will increase with an increase in the number of terminals located in cell edges, and send a notification of the required blank time slots to the first base station. The first base station determines whether system throughput is anticipated to improve, based on the above notifications, and adjusts the length of blank time slots.
    Type: Grant
    Filed: November 19, 2012
    Date of Patent: February 24, 2015
    Assignee: Hitachi, Ltd.
    Inventors: Tomonori Yamamoto, Rintaro Katayama, Shigenori Hayase
  • Patent number: 8923866
    Abstract: In femtocell operation, when a wireless communication terminal whose ID is not registered (ID unregistered terminal) has entered a femtocell's area, the disclosed invention prevents interference between the femtocell and the ID unregistered terminal and interference between the ID unregistered terminal and an ID registered radio communication terminal and prevents a decrease in the throughput of the femtocell and these terminals. In a radio coverage area formed by a radio base station, if a drop of received power from a radio communication terminal occurs and the frequency of reporting the ID of the base station now communicating with the terminal has become less than a given value, it is decided that the terminal is located indoors. For the terminal, if its handover to a femtocell was found to be rejected by MME, the terminal is temporarily permitted to be handed over to a femtocell.
    Type: Grant
    Filed: February 7, 2013
    Date of Patent: December 30, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Ryouichi Tanaka, Koji Wakayama, Tsuyoshi Kajita, Tomonori Yamamoto
  • Patent number: 8818443
    Abstract: A femtocell base station collects the terminal distribution within the cell and selects terminals to represent the cell-center and the cell-edge from among the terminals within the cell. The femtocell base station also calculates maximum transmit power for the respective the cell-center and cell-edge terminals allowable by the macrocell base station. The femtocell base station sets the respective transmit power of the cell-center and the cell-edge in a range that will not exceed the maximum transmit power, adjusts the transmit power control parameter to allow control by the terminal at the power value that was set, and notifies the terminal. Communication with high throughput can in this way be attained for terminals in cells within the femtocell base station during uplink communications to the femtocell base station, and interference applied to the terminals in the macrocell base station can be suppressed.
    Type: Grant
    Filed: June 22, 2011
    Date of Patent: August 26, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Tomonori Yamamoto, Rintaro Katayama, Hirotake Ishii
  • Patent number: 8811286
    Abstract: Timing division multiplexing is conducted between the cells to avoid intercell interference. Transmission timing in a time slot pattern has a given interval. A base station determines the transmission timing based on measured uplink interference power. For example, an uplink time slot pattern in which the measured uplink interference power is smaller is selected. A downlink time slot pattern is assigned so that a response to HARQ is returned at that timing. If traffic is busy, additional time slot pattern may be assigned. In determination of the traffic volume, for example, the queued buffer size, the number of connected terminals, or the number of connections to a higher-level device can be used. Assignment timing can be an initial setup time, or a fluctuation detection time of a channel which can be realized by collection of report information on a downlink communication quality, periodic monitor of uplink interference information.
    Type: Grant
    Filed: May 2, 2012
    Date of Patent: August 19, 2014
    Assignee: Hitachi Ltd.
    Inventors: Tomonori Yamamoto, Rintaro Katayama, Keisuke Takeuchi
  • Publication number: 20140222025
    Abstract: A surgical robot including an imaging system comprising at least one camera, a processor in communication with the imaging system, a manipulation system in communication with the processor, and a visual display in communication with the processor. The processor is operable to calculate a mechanical property estimate for an area of an environment based on an environment model of tool-environment interaction data, create a composite image comprising a mechanical property map of the mechanical property estimate overlaid on an environment image from the at least one camera, and output the composite image on the visual display.
    Type: Application
    Filed: April 9, 2014
    Publication date: August 7, 2014
    Applicant: The Johns Hopkins University
    Inventors: Allison M. Okamura, Tomonori Yamamoto, Balazs P. Vagvolgyi
  • Patent number: 8744362
    Abstract: A cellular radio communication system includes a first mobile terminal, a base station that performs radio communication with first mobile terminals, a second mobile terminal, and a second base station that performs radio communication with second mobile terminals. In the downlink communication, the base station selects a high data rate mode when the radio interference from the base station to the second mobile terminals that are located close to an edge of a communication area of the second base station is small. The base station selects an interference mitigation mode in the downlink communication when the radio interference from the base station to the second mobile terminals that are located close to the edge of the communication area of the second base station is large. Thus, inter-cell interference control can be performed in collaboration with base stations in the radio communication system without having communication interface between the base stations.
    Type: Grant
    Filed: June 2, 2011
    Date of Patent: June 3, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Takuji Kawahatsu, Rintaro Katayama, Satoshi Tamaki, Tomonori Yamamoto
  • Patent number: 8700123
    Abstract: A surgical robot including an imaging system comprising at least one camera, a processor in communication with the imaging system, a manipulation system in communication with the processor, and a visual display in communication with the processor. The processor is operable to calculate a stiffness estimate for an area of an environment based on an environment model of tool-environment interaction data, create a composite image comprising a stiffness map of the stiffness estimate overlaid on an environment image from the at least one camera, and output the composite image on the visual display.
    Type: Grant
    Filed: October 20, 2009
    Date of Patent: April 15, 2014
    Assignee: The Johns Hopkins University
    Inventors: Allison Mariko Okamura, Tomonori Yamamoto, Peter Balazs Vagvolgyi
  • Patent number: 8660049
    Abstract: In a time slot in which a first base station for performing a multicast transmission executes the multicast transmission, a second base station which does not perform the multicast transmission does not perform a unicast data transmission. The time slot in which the first base station performs the multicast transmission is notified to the second base station from a multicast control apparatus for performing scheduling of the multicast transmission to the first base station. Information to receive the multicast transmission is notified from the second base station to a terminal connected to the second base station.
    Type: Grant
    Filed: January 28, 2011
    Date of Patent: February 25, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Rintaro Katayama, Satoshi Tamaki, Tomonori Yamamoto, Hirotake Ishii
  • Patent number: 8560000
    Abstract: A communication device includes pilot signal sending part and transmit power control part and holds a criterion value indicating target channel quality for mobile stations within the area covered by the base station. It creates quality data from reports from one or plural mobile stations, stores the quality data, creates a first representative value indicating average channel quality for the mobile station(s) from the stored quality data, and changes the transmit power depending on the result of comparison between the first representative value and the criterion value. It creates a second representative value indicating distribution of low channel quality from the stored quality data and updates the criterion value depending on the result of comparison between the second representative value and the criterion value.
    Type: Grant
    Filed: January 7, 2011
    Date of Patent: October 15, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Rintaro Katayama, Satoshi Tamaki, Tomonori Yamamoto, Hirotake Ishii, Shigenori Hayase
  • Publication number: 20130244658
    Abstract: In femtocell operation, when a wireless communication terminal whose ID is not registered (ID unregistered terminal) has entered a femtocell's area, the disclosed invention prevents interference between the femtocell and the ID unregistered terminal and interference between the ID unregistered terminal and an ID registered radio communication terminal and prevents a decrease in the throughput of the femtocell and these terminals. In a radio coverage area formed by a radio base station, if a drop of received power from a radio communication terminal occurs and the frequency of reporting the ID of the base station now communicating with the terminal has become less than a given value, it is decided that the terminal is located indoors. For the terminal, if its handover to a femtocell was found to be rejected by MME, the terminal is temporarily permitted to be handed over to a femtocell.
    Type: Application
    Filed: February 7, 2013
    Publication date: September 19, 2013
    Applicant: HITACHI, LTD.
    Inventors: Ryouichi TANAKA, Koji WAKAYAMA, Tsuyoshi KAJITA, Tomonori YAMAMOTO
  • Patent number: 8520612
    Abstract: A method for radio resource control is carried out in a radio communications system including multiple base stations. In this method, a radio resource that can be used by the base stations is divided into multiple first radio resources on the frequency axis. Then one or more of the first radio resources are allocated to a second radio resource for initially transmitting a packet and the other first radio resources are allocated to a third radio resource for retransmitting the packet.
    Type: Grant
    Filed: February 18, 2010
    Date of Patent: August 27, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Tomonori Yamamoto, Rintaro Katayama, Keisuke Takeuchi, Koki Uwano
  • Patent number: 8503295
    Abstract: A base station is connected to wired and wireless networks to send a call that is received from the wired network to the wireless network at a predetermined quality of service (QoS), select one or more combinations of a set of modulation and coding scheme, and a radio resource amount that are associated with a QoS set in a newly incoming call, determine the radio resource amount that is equal to or less than a amount of the unassigned radio resources, assign, to the newly incoming call, the combination that is associated with the determined radio resource amount and the QoS set in the newly incoming call, reduce the radio resources assigned to the ongoing call without changing the QoS, and assign, to the newly incoming call, an amount of radio resources released from the ongoing call and modulation and coding scheme associated with this released radio resource amount.
    Type: Grant
    Filed: December 18, 2009
    Date of Patent: August 6, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Keisuke Takeuchi, Rintaro Katayama, Tomonori Yamamoto, Koki Uwano
  • Patent number: 8477682
    Abstract: Conventionally, different HARQ processes 801 and 802 (subframes T1 and T2) transmit data packets B and D, respectively. One data packet corresponds to one process and is retransmitted as necessary one by one on a process basis, degrading the usage efficiency of frequency and time resources. To solve this problem, downlink data packets B and D, when needed to be retransmitted, are spatially multiplexed in the different HARQ processes 801 and 802. The data packets are simultaneously retransmitted to the same terminal as process 805 (subframe T3).
    Type: Grant
    Filed: August 5, 2010
    Date of Patent: July 2, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Keisuke Takeuchi, Rintaro Katayama, Tomonori Yamamoto, Koki Uwano
  • Patent number: 8462718
    Abstract: Resources are assigned in units of resource blocks each composed of one or more subcarriers, inter-cell interference adjustment control information is notified to each other among base stations, a transmit power limitation on each of the resource blocks in a cell is decided based on the inter-cell interference adjustment control information; and the decision of the transmit power limitation is changed sequentially beginning at a resource block having a transmit power limitation different from the transmit power limitation on an adjacent resource block.
    Type: Grant
    Filed: May 27, 2010
    Date of Patent: June 11, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Satoshi Tamaki, Rintaro Katayama, Hirotake Ishii, Tomonori Yamamoto
  • Patent number: 8463272
    Abstract: An object of the invention is to provide a wireless communication system in which the load of each cell and interference between cells are taken into account. In a handover-candidate base station and a handover-source base station, parameters for interference-reducing scheduling and handover facilitating processing are adjusted based on the mutual load information. When the handover-candidate base station, to be used for load balancing, is a large-diameter cell, transmit power control and frequency scheduling are adjusted by taking account of the load state at a cell edge. When the handover-source base station has a small-diameter cell, the number of terminals to be handed over is adjusted by taking account of the load state of the handover-candidate base station. Thus, both of interference control and load balancing are achieved.
    Type: Grant
    Filed: January 6, 2011
    Date of Patent: June 11, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Tomonori Yamamoto, Satoshi Tamaki, Rintaro Katayama, Hirotake Ishii
  • Patent number: 8344583
    Abstract: Provided is an automotive alternator having structure for preventing entry and discharging of foreign matters irrespective of a posture of a brush unit, to thereby allow normalization of the brush unit. The brush unit of the automotive alternator includes a slip ring, a brush, a brush holder, and a slip ring cover coaxially spaced from the slip ring and having an inner peripheral surface surrounding substantially an entire periphery of the slip ring. The inner peripheral surface of the slip ring cover has a tapered surface increasing in diameter from a first end on the frame side toward a second end having a fully-open opening. The fully-open opening is sealed by a sealing member that forms a labyrinth seal with the second end.
    Type: Grant
    Filed: November 1, 2010
    Date of Patent: January 1, 2013
    Assignee: Mitsubishi Electric Corp.
    Inventor: Tomonori Yamamoto
  • Publication number: 20120281569
    Abstract: Timing division multiplexing is conducted between the cells to avoid intercell interference. Transmission timing in a time slot pattern has a given interval. A base station determines the transmission timing based on measured uplink interference power. For example, an uplink time slot pattern in which the measured uplink interference power is smaller is selected. A downlink time slot pattern is assigned so that a response to HARQ is returned at that timing. If traffic is busy, additional time slot pattern may be assigned. In determination of the traffic volume, for example, the queued buffer size, the number of connected terminals, or the number of connections to a higher-level device can be used. Assignment timing can be an initial setup time, or a fluctuation detection time of a channel which can be realized by collection of report information on a downlink communication quality, periodic monitor of uplink interference information.
    Type: Application
    Filed: May 2, 2012
    Publication date: November 8, 2012
    Applicant: HITACHI, LTD.
    Inventors: Tomonori YAMAMOTO, Rintaro KATAYAMA, Keisuke TAKEUCHI
  • Publication number: 20120120876
    Abstract: In a cellular radio communication system, a base station or a mobile station has a TA (Time Alignment)-range-out detection function, so that when a TA-range-out state that is unable to compensate with a guard interval is detected, the transmission condition of an uplink signal at the mobile station is changed by the mobile station autonomously or by the base station and the mobile station cooperatively.
    Type: Application
    Filed: January 24, 2012
    Publication date: May 17, 2012
    Inventors: Tomonori YAMAMOTO, Katsuhiko TSUNEHARA, Satoshi TAMAKI, May TAKADA, Mikio KUWAHARA
  • Patent number: 8111683
    Abstract: In a cellular radio communication system, a base station or a mobile station has a TA (Time Alignment)-range-out detection function, so that when a TA-range-out state that is unable to compensate with a guard interval is detected, the transmission condition of an uplink signal at the mobile station is changed by the mobile station autonomously or by the base station and the mobile station cooperatively.
    Type: Grant
    Filed: February 24, 2009
    Date of Patent: February 7, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Tomonori Yamamoto, Katsuhiko Tsunehara, Satoshi Tamaki, May Takada, Mikio Kuwahara
  • Patent number: D709830
    Type: Grant
    Filed: December 12, 2013
    Date of Patent: July 29, 2014
    Assignee: Mitsubishi Electric Corporation
    Inventors: Kazunori Tanaka, Tomonori Yamamoto