Patents by Inventor Kenzaburo Fujishima

Kenzaburo Fujishima 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: 20160323421
    Abstract: When a TCP packet communication acceleration technique is applied to a wireless communication network, an acceleration effect is determined according to various pieces of information in real time, and acceleration control is dynamically performed to efficiently accelerate the communication by the use of the TCP of a wireless terminal present in the wireless communication network. A wireless communication system including at least one wireless terminal and at least one base station that communicates with the wireless terminal further includes an information collection server that collects various pieces of information from the base station and the wireless terminal. The base station includes a packet acceleration unit that accelerates a TCP packet communication, and the information collection server determines whether to accelerate the base station from the various pieces of information, or not, and controls the acceleration of the base station on the basis of its determination result.
    Type: Application
    Filed: April 13, 2016
    Publication date: November 3, 2016
    Applicant: HITACHI, LTD.
    Inventors: Yoshiki SAKURAI, Takashi ISOBE, Kenzaburo FUJISHIMA
  • Publication number: 20160198458
    Abstract: It is provided a wireless communication system comprising base stations that transmit data to a terminal with cooperation by the base stations. The terminal communicates with the base stations. The terminal periodically transmits, to one of the base stations, information necessary for data transmission from a single base station out of the base stations. Each of the base stations determines whether the terminal needs data transmission through a cooperation among the base stations, and transmits a cooperation information transmission instruction to the terminal, which includes information necessary to execute the data transmission in order to cooperate among the base stations in the case where it is determined that the terminal needs the data transmission through the cooperation among the base stations. The terminal transmits the cooperation information to the base stations in a case of receiving the cooperation information transmission instruction.
    Type: Application
    Filed: March 17, 2016
    Publication date: July 7, 2016
    Inventors: Go ONO, Kenzaburo FUJISHIMA, May TAKADA, Koki UWANO
  • Patent number: 9350830
    Abstract: To prevent the switching time influences power saving performance and packet loss prevention performance, it is provided a wireless communication base station for communicating with a terminal, comprising: a plurality of baseband signal processing units for performing baseband signal processing; a baseband allocation unit for allocating the baseband signal processing to the plurality of baseband signal processing units; and a linear processing unit for composing signals processed by the plurality of baseband signal processing units. The baseband allocation unit selects, for each data block, a baseband signal processing unit to which the baseband signal processing for the each data block is to be allocated out of the plurality of baseband signal processing units. Each of the plurality of baseband signal processing units performs the allocated baseband signal processing.
    Type: Grant
    Filed: January 15, 2014
    Date of Patent: May 24, 2016
    Assignee: HITACHI, LTD.
    Inventors: Shigenori Hayase, Kenzaburo Fujishima, Hirotake Ishii, Masanori Taira
  • Patent number: 9320042
    Abstract: The present invention is directed to achievement of a data transmission control to cause base stations to cooperate with one another, taking into account efficient use of radio resources. A wireless communication system, which is an aspect of the present invention, includes: a first base station; a second base station connected via a wired network; and a wireless communication terminal that conducts at least one of single data transmission in which a single base station transmits data and cooperative data transmission in which a plurality of base stations cooperate to transmit data. The base stations notify the wireless communication terminal of a condition indicating a case where the cooperative data transmission can be performed. If the communication quality of the propagation path meets the condition, the wireless communication terminal transmits, to the base stations, information that is required for the cooperative data transmission.
    Type: Grant
    Filed: April 9, 2010
    Date of Patent: April 19, 2016
    Assignee: Hitachi, Ltd.
    Inventors: Go Ono, Kenzaburo Fujishima, Mikio Kuwahara
  • Publication number: 20160057674
    Abstract: The invention is intended to, even in a situation where there are many candidate wireless base stations (WBSs) to which a mobile terminal (MT) may connect, get information of communication conditions between the MT and each of those WBSs and determine an WBS to which the MT should connect in a shorter time. A coverage area of the first WBS is overlapped partially at least by a coverage area of the second WBS. The MT transmits a signal for connection using a predetermined frequency. Upon receiving the signal for connection, the second WBSs each notify the WBS communication manager of their reception results of the signal for connection. The WBS communication manager selects a second WBS to communicate with the MT based on the reception results and notifies the selected second WBS to transmit a response signal to the signal for connection to the MT.
    Type: Application
    Filed: March 15, 2013
    Publication date: February 25, 2016
    Inventors: Eriko TAKEDA, Takashi ISHIKAWA, Satoshi TAMAKI, Go ONO, Katsuhiko TSUNEHARA, Kenzaburo FUJISHIMA
  • Patent number: 9203575
    Abstract: A base station performs an association between frequency range and combinations of a plurality of base stations including an local base station to notify a terminal of the association. According to the notified association, the terminal, for each frequency, calculates quality of communication with one base station or quality of communication with the combination of the plurality of base stations. The base station and the control station determine the base station/the plurality of base stations that communicate with the terminal, the wireless resource and the transmission scheme, based on the result. Further, the base station selects whether to notify an entirety of or a part of the association to the terminal using positional information of the terminal. Since the association information that is unnecessary for the terminal is not communicated, it is possible to further lighten the load of control.
    Type: Grant
    Filed: October 27, 2011
    Date of Patent: December 1, 2015
    Assignee: HITACHI, LTD.
    Inventors: Yunjian Jia, Kenzaburo Fujishima
  • Patent number: 9143269
    Abstract: A method of wireless communication for communication between a base station and a plurality of terminal apparatuses, the method including: dividing an available frequency into a plurality of segments and notifying control information to the terminal apparatus, the control information including setting of a segment of the plurality of segments, communication quality of which will be fed back by the terminal apparatus, and cancellation of a segment of the plurality of segments, communication quality of which has already been fed back from the terminal apparatus; and feeding back communication quality related to a predetermined segment to the base station in accordance with the control information by the terminal apparatus.
    Type: Grant
    Filed: June 12, 2014
    Date of Patent: September 22, 2015
    Assignee: Hitachi, Ltd.
    Inventors: Kenzaburo Fujishima, Masanori Taira
  • Patent number: 9008727
    Abstract: A base station broadcasts a message saying that transmittable ranging codes are limited by antenna IDs to limit antennas and the ranging codes to be searched, thereby reducing a processing load of the search. In a cellular radio communication system in which a base station device is connected to plural antennas, and antenna IDs for identifying the antennas are transmitted from the respective antennas, the base station device broadcasts a message saying that a group of ranging codes transmittable by a terminal device is limited by the antenna IDs, the terminal device receives the message, identifies the antenna ID, selects the ranging code from the group of the ranging codes corresponding to the antenna ID, and transmits the selected ranging code.
    Type: Grant
    Filed: June 20, 2012
    Date of Patent: April 14, 2015
    Assignee: Hitachi, Ltd.
    Inventors: Mikio Kuwahara, Kenzaburo Fujishima, Yunjian Jia
  • Patent number: 8989157
    Abstract: In an environment in which a macro base station and a low transmission power base station exist, the ratio of the interference reduction time period of the macro base station is optimized, and the throughput of the low transmission power base station is improved, while minimizing a reduction in throughput. The macro base station causes a high interference to other base stations and one or a plurality of low power nodes (LPN) subjected to interference from the macro base station. The macro base station sets first and second data transmission time periods and then determines the ratio of the second time period and the pattern of the first time period and the second time period based on communication quality in the first time period and communication quality in the second time period of the macro base station and the LPN.
    Type: Grant
    Filed: February 27, 2013
    Date of Patent: March 24, 2015
    Assignee: Hitachi, Ltd.
    Inventors: Hitoshi Ishida, Kenzaburo Fujishima, Yunjian Jia
  • Publication number: 20150036624
    Abstract: Provided is a base station apparatus including an upper layer processor and a lower layer processor. The upper layer processor: holds allocation rights information representing that a cell has a right to allocate a part of a wireless resource owned by the cell to a terminal belonging to the cell, and does not have a right to allocate a remaining part of the wireless resource; allocates the part of the wireless resource which the cell has the right to allocate out of the wireless resource owned by the cell to the terminal; and instructs the lower layer processor to carry out wireless signal processing for the communication to/from the terminal. The lower layer processor: carries out, in accordance with the instruction to carry out the wireless signal processing, the wireless signal processing for the communication to/from the terminal; and notifies the upper layer processor of a result thereof.
    Type: Application
    Filed: August 4, 2014
    Publication date: February 5, 2015
    Applicant: Hitachi, Ltd.
    Inventors: Kenzaburo FUJISHIMA, Masanori TAIRA, Shigenori HAYASE
  • Patent number: 8942757
    Abstract: Disclosed are a communication control device, a communication control method and the system thereof, which provide efficient multi-base station joint services in a mobile communication system using dynamic clustering. Optimal base station clustering is chosen according to the communication state between a terminal and each base station. The communication control device connects with multiple base stations through a network, and clusters the multiple base stations dynamically so that the clustered multiple base stations can provide services for the mobile terminal in union. The communication control device comprises: an interface, connecting with multiple base stations, receiving channel state information related to the mobile terminal from each base station; a memory unit, storing the channel state information of the mobile terminal received from the interface; a control unit, clustering each base station dynamically according to the channel state information of the mobile terminal stored in the memory unit.
    Type: Grant
    Filed: April 29, 2010
    Date of Patent: January 27, 2015
    Assignee: Hitachi, Ltd.
    Inventors: Yunjian Jia, Kenzaburo Fujishima, Hideya Yoshiuchi, Peng Yang, Yuanchen Ma, Lu Geng, Sheng Zhou, Zhisheng Niu, Jie Gong
  • Patent number: 8897161
    Abstract: To reduce an uplink interference in a network with a first base station of a large output and a second base station of a small output. Detecting the interference, the second base station urges the first base station to hand over a terminal causing it to the second base station. Multiple base stations and one or more terminals exist in this system, each terminal connects with one base station, and a serving base station is changed according to a communication state of each terminal. If the different second base station other than the first base station to which the terminal connects detects a large interference, the second base station will multicast transmit information for urging handover to the base stations except itself. The base station having received the information specifies a terminal giving the interference to the second base station, and makes it to be handed over thereto.
    Type: Grant
    Filed: July 10, 2012
    Date of Patent: November 25, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Kenzaburo Fujishima, Tsuyoshi Tamaki, Rintaro Katayama, Hitoshi Ishida
  • Patent number: 8891417
    Abstract: To secure a constant level or more of radio communication quality for each user equipment performing radio communication with a base station apparatus, and to increase the number of user equipment which the base station apparatus can accommodate under a condition of assuring the radio communication quality. In a radio communication system where there exist a base station apparatus having multiple antennas and user equipment for performing radio communication with a first antenna group including one or more of the antennas, the first antenna group is made configurable for each user equipment individually, and addition/deletion of the antenna to/from the first antenna group is performed based on the communication quality of each user equipment so that the number of antennas within the first antenna group may be minimized within a range satisfying a required value of the communication quality between the base station apparatus ad the user equipment.
    Type: Grant
    Filed: February 3, 2012
    Date of Patent: November 18, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Kenzaburo Fujishima, Tsuyoshi Tamaki, Yunjian Jia, Hitoshi Ishida
  • Patent number: 8891390
    Abstract: Provided is a wireless communication system which includes a wireless communication unit using plural frequency bands and plural antennas. The system changes the transmission power of each antenna, based on the interference of each of the frequency bands from the neighbor base station along the antenna direction. The system estimates the number of antennas necessary for transmission in response to a user requirement, and determines a necessary antenna in accordance with the antenna direction in which the terminal is located, and further changes the transmission power of each antenna.
    Type: Grant
    Filed: December 1, 2011
    Date of Patent: November 18, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Hajime Kanzaki, Kenzaburo Fujishima, Mikio Kuwahara, Katsuhiko Tsunehara
  • Publication number: 20140293920
    Abstract: A method of wireless communication for communication between a base station and a plurality of terminal apparatuses, the method including: dividing an available frequency into a plurality of segments and notifying control information to the terminal apparatus, the control information including setting of a segment of the plurality of segments, communication quality of which will be fed back by the terminal apparatus, and cancellation of a segment of the plurality of segments, communication quality of which has already been fed back from the terminal apparatus; and feeding back communication quality related to a predetermined segment to the base station in accordance with the control information by the terminal apparatus.
    Type: Application
    Filed: June 12, 2014
    Publication date: October 2, 2014
    Inventors: Kenzaburo Fujishima, Masanori Taira
  • Publication number: 20140226619
    Abstract: To reduce power consumption of a mobile station, this invention provides a wireless communication method for communicating between a base station and a plurality of terminals using a plurality of channels, the channels being slots obtained by dividing frequency-divided carriers by time, in which the base station allocates a set of the channels which is composed of a plurality of neighboring carriers and/or a plurality of successive slots for the each terminal, and the base station allocates at least one of the channels included in the channel sets for packet transmission the terminals.
    Type: Application
    Filed: April 22, 2014
    Publication date: August 14, 2014
    Applicant: Hitachi, Ltd.
    Inventors: Mikio KUWAHARA, Kenzaburo FUJISHIMA, Masanori TAIRA
  • Publication number: 20140219125
    Abstract: By a base station that is not limited to a cell concept, the system control cost is controlled and an area of high-communication-speed/high-communication-quality is expanded. There are provided fixed-cell support base-station devices 420 and 421 having functions of physical layer processing and higher layer processing according to the cell concept in the related art and an unfixed-area support base-station device 430 having a physical layer processing function that is not limited to the cell concept. The unfixed-cell support base-station device 430 performs physical layer signal processing for a terminal in a low throughput area and selects an arbitrary antenna group from antennas or antenna group linked to the fixed-cell support base stations 420 and 421, and the fixed-cell support base stations 420 and 421 transmit their own transmission signals and transmission signals directed to the terminal together.
    Type: Application
    Filed: August 29, 2012
    Publication date: August 7, 2014
    Applicant: HITACHI, LTD.
    Inventors: Yunjian Jia, Tsuyoshi Tamaki, Kenzaburo Fujishima, Hitoshi Ishida
  • Patent number: 8792444
    Abstract: In the case where a base station other than of a distributed antenna system provides a time or frequency at which a transmitted power is low, an antenna group configuration unit estimates a communication area of a mobile station using an uplink reference signal that the mobile station transmits, calculates an inter-system interference power for the communication area of each mobile station based on a received power of the out-of-system base station that the each mobile station reports, calculates the inter-system interference power to each of antennas by averaging the inter-system interference powers that the multiple mobile stations report, and decides antennas that form an antenna group according to magnitudes of the calculated inter-system interference powers.
    Type: Grant
    Filed: June 5, 2012
    Date of Patent: July 29, 2014
    Assignee: HItachi, Ltd.
    Inventors: Hitoshi Ishida, Kenzaburo Fujishima, Yunjian Jia
  • Patent number: 8787321
    Abstract: A method of wireless communication for communication between a base station and a plurality of terminal apparatuses, the method including: dividing an available frequency into a plurality of segments and notifying control information to the terminal apparatus, the control information including setting of a segment of the plurality of segments, communication quality of which will be fed back by the terminal apparatus, and cancellation of a segment of the plurality of segments, communication quality of which has already been fed back from the terminal apparatus; and feeding back communication quality related to a predetermined segment to the base station in accordance with the control information by the terminal apparatus.
    Type: Grant
    Filed: September 13, 2012
    Date of Patent: July 22, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Kenzaburo Fujishima, Masanori Taira
  • Patent number: 8787146
    Abstract: A discontinuous change in a transmission timing in a time domain, which is caused by a transmission timing adjustment processing of an OFDMA uplink or the like, brings about a discontinuous rotation of a signal phase in a frequency domain, resulting in reduced communication quality. A wireless communication system of the present invention allows the signal phase of the frequency domain in a receiving station to be continuous before and after the timing adjustment processings by controlling a signal sequence in a transmission signal after conversion in the time domain in synchronization with the timing adjustment processing.
    Type: Grant
    Filed: February 16, 2009
    Date of Patent: July 22, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Satoshi Tamaki, Mikio Kuwahara, Kenzaburo Fujishima, Pinai Linwong, Katsuhiko Tsunehara