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).
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Patent number: 9161277Abstract: Interference applied to neighbor cells during terminal handovers can be reduced in wireless communication systems containing base stations having different cell sizes. A serving cell makes handover judgment criteria easier based on pre-acquired cell size information on its own cell and cell size information of neighbor cells in order to facilitate terminal handovers from a base station with a large cell size to a base station with a small cell size. The serving cell finds evaluation function values based on the propagation state (e.g. reference signal received power) between the terminal and target cell, and the interference and load information exchanged between the base stations, and selects the terminal for handover by comparing the evaluation function value with the handover criteria value. The system selects a target cell having a good effect in lowering interference such as a cell with large reference signal received power acquired from a terminal, to serve as the handover destination.Type: GrantFiled: February 11, 2011Date of Patent: October 13, 2015Assignee: HITACHI, LTD.Inventors: Tomonori Yamamoto, Satoshi Tamaki, Rintaro Katayama, Hirotake Ishii
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Publication number: 20150257160Abstract: Even when a downlink radio traffic volume is larger than an uplink radio traffic volume in a radio communication system, but uplink resources are redundant in a related art radio communication system, free uplink resources could not be sufficiently utilized. In a base station having a cellular unit that performs cellular communication with a terminal, and a D2D unit that performs communication with the terminal through a device-to-device communication system, when the downlink radio resources get tight, and the uplink radio resources are redundant, the D2D unit of the base station conducts transmission and reception with the terminal with the use of the uplink radio resources.Type: ApplicationFiled: January 15, 2015Publication date: September 10, 2015Inventors: Hitoshi ISHIDA, Tomonori YAMAMOTO, Satoshi TAMAKI, Hirotake ISHII
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Patent number: 9083450Abstract: A macro base station includes a communication prohibited period setting unit of setting an uplink communication prohibited period to a user equipment belonging to the base station, and prohibits an uplink communication from the user equipment to a wireless communication base station per se during the uplink communication prohibited period. The user equipments belonging to the wireless communication base station per se and the second base station are divided into plural groups, and the uplink communication prohibited period is set to different time periods for the respective groups. Thereby, a communication characteristic is prohibited from being deteriorated at the second base station by an interference affected with the second base station separately from the first base station by the user equipment communicating with the first base station in the uplink communication.Type: GrantFiled: January 14, 2013Date of Patent: July 14, 2015Assignee: Hitachi, Ltd.Inventors: Shigenori Hayase, Tsuyoshi Tamaki, Tomonori Yamamoto, Rintaro Katayama
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Publication number: 20150189583Abstract: The present invention provides a method of controlling the selection of a cell in a radio communication system for increasing the capacity of the system by effectively utilizing a small cell base station and a base station apparatus for realizing it. At least one base station of a macrocell base station and a small cell base station is provided with plural antennas, and the base station selects a cell and adjusts a criterion for reselection by generating processing gain using the plural antennas by signal processing and performing a cell selection bias correcting process using the processing gain using the plural antennas.Type: ApplicationFiled: November 29, 2012Publication date: July 2, 2015Inventors: Satoshi Tamaki, Tomonori Yamamoto, Hitoshi Ishida, Eriko Takeda, Go Ono
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Publication number: 20150087324Abstract: A base station is provided with a plurality of radio units that communicate with a terminal, and a control device connected to the plurality of radio units. When there is a large number of terminals positioned at a boundary of the communication areas of a first radio unit and a second radio unit among the plurality of radio units, the control device makes a first cell ID of the first radio unit and a second cell ID of the second radio unit being identical.Type: ApplicationFiled: August 29, 2014Publication date: March 26, 2015Inventors: Hitoshi ISHIDA, Tomonori YAMAMOTO, Satoshi TAMAKI, Rintaro KATAYAMA, Eriko TAKEDA, Tsuyoshi TAMAKI
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Patent number: 8964777Abstract: 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: GrantFiled: November 19, 2012Date of Patent: February 24, 2015Assignee: Hitachi, Ltd.Inventors: Tomonori Yamamoto, Rintaro Katayama, Shigenori Hayase
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Patent number: 8923866Abstract: 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: GrantFiled: February 7, 2013Date of Patent: December 30, 2014Assignee: Hitachi, Ltd.Inventors: Ryouichi Tanaka, Koji Wakayama, Tsuyoshi Kajita, Tomonori Yamamoto
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Patent number: 8818443Abstract: 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: GrantFiled: June 22, 2011Date of Patent: August 26, 2014Assignee: Hitachi, Ltd.Inventors: Tomonori Yamamoto, Rintaro Katayama, Hirotake Ishii
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Patent number: 8811286Abstract: 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: GrantFiled: May 2, 2012Date of Patent: August 19, 2014Assignee: Hitachi Ltd.Inventors: Tomonori Yamamoto, Rintaro Katayama, Keisuke Takeuchi
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Publication number: 20140222025Abstract: 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: ApplicationFiled: April 9, 2014Publication date: August 7, 2014Applicant: The Johns Hopkins UniversityInventors: Allison M. Okamura, Tomonori Yamamoto, Balazs P. Vagvolgyi
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Patent number: 8744362Abstract: 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: GrantFiled: June 2, 2011Date of Patent: June 3, 2014Assignee: Hitachi, Ltd.Inventors: Takuji Kawahatsu, Rintaro Katayama, Satoshi Tamaki, Tomonori Yamamoto
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Patent number: 8700123Abstract: 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: GrantFiled: October 20, 2009Date of Patent: April 15, 2014Assignee: The Johns Hopkins UniversityInventors: Allison Mariko Okamura, Tomonori Yamamoto, Peter Balazs Vagvolgyi
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Patent number: 8660049Abstract: 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: GrantFiled: January 28, 2011Date of Patent: February 25, 2014Assignee: Hitachi, Ltd.Inventors: Rintaro Katayama, Satoshi Tamaki, Tomonori Yamamoto, Hirotake Ishii
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Patent number: 8560000Abstract: 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: GrantFiled: January 7, 2011Date of Patent: October 15, 2013Assignee: Hitachi, Ltd.Inventors: Rintaro Katayama, Satoshi Tamaki, Tomonori Yamamoto, Hirotake Ishii, Shigenori Hayase
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Publication number: 20130244658Abstract: 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: ApplicationFiled: February 7, 2013Publication date: September 19, 2013Applicant: HITACHI, LTD.Inventors: Ryouichi TANAKA, Koji WAKAYAMA, Tsuyoshi KAJITA, Tomonori YAMAMOTO
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Patent number: 8520612Abstract: 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: GrantFiled: February 18, 2010Date of Patent: August 27, 2013Assignee: Hitachi, Ltd.Inventors: Tomonori Yamamoto, Rintaro Katayama, Keisuke Takeuchi, Koki Uwano
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Patent number: 8503295Abstract: 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: GrantFiled: December 18, 2009Date of Patent: August 6, 2013Assignee: Hitachi, Ltd.Inventors: Keisuke Takeuchi, Rintaro Katayama, Tomonori Yamamoto, Koki Uwano
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Patent number: 8477682Abstract: 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: GrantFiled: August 5, 2010Date of Patent: July 2, 2013Assignee: Hitachi, Ltd.Inventors: Keisuke Takeuchi, Rintaro Katayama, Tomonori Yamamoto, Koki Uwano
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Patent number: 8462718Abstract: 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: GrantFiled: May 27, 2010Date of Patent: June 11, 2013Assignee: Hitachi, Ltd.Inventors: Satoshi Tamaki, Rintaro Katayama, Hirotake Ishii, Tomonori Yamamoto
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Patent number: D709830Type: GrantFiled: December 12, 2013Date of Patent: July 29, 2014Assignee: Mitsubishi Electric CorporationInventors: Kazunori Tanaka, Tomonori Yamamoto