Patents by Inventor Yoshiharu Tajima

Yoshiharu Tajima 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: 9173243
    Abstract: A wireless communication system is provided in which a relay station relays wireless communication between a base station and a mobile station. The relay station includes an acquiring unit and a notifying unit. The acquiring unit acquires, from the base station that retains information on the mobile station used for the wireless communication, identification information on the base station. The notifying unit notifies the mobile station of the identification information acquired by the acquiring unit. Furthermore, the mobile station includes a reconnecting unit. When connection with the relay station is released, the reconnecting unit performs a reconnection request with respect to the base station that is identified by the identification information that is notified by the relay station.
    Type: Grant
    Filed: June 4, 2013
    Date of Patent: October 27, 2015
    Assignee: FUJITSU LIMITED
    Inventors: Yoshiharu Tajima, Yoshinori Tanaka, Yoshihiro Kawasaki, Yoshiaki Ohta, Katsumasa Sugiyama, Kazuhisa Obuchi
  • Patent number: 9118479
    Abstract: A mobile communication system comprises a base station and a relay station to relay data transmitted/received between the base station and a mobile station. The base station includes a first scheduler to perform scheduling of initial transmission of the data transmitted/received between the base station and the mobile station via the relay station, and a first manager to manage predetermined wireless resources which are periodically used, as wireless resources used for the initial transmission of the data. The relay station includes a second scheduler configured to perform scheduling of transmission of a message for confirming necessity of retransmission of the data and retransmission of the data and a second manager configured to manage wireless resources used for the transmission of the message and the retransmission of the data.
    Type: Grant
    Filed: September 14, 2012
    Date of Patent: August 25, 2015
    Assignee: FUJITSU LIMITED
    Inventors: Yoshiaki Ohta, Yoshiharu Tajima, Yoshinori Tanaka, Yoshihiro Kawasaki, Kazuhisa Obuchi, Katsumasa Sugiyama, Masatsugu Shimizu
  • Patent number: 9113466
    Abstract: The relay station performs wireless communications with a base station, and a mobile station performs wireless communications with the base station or relay station. The relay station limits reception of a radio signal from the base station at timing at which a radio signal is transmitted to the mobile station. The relay station transmits a message #1 about random access to the base station. The base station transmits a message #2 at timing which is determined based on whether a transmission source of the message #1 is the relay station. The relay station receives the message #2 from the base station.
    Type: Grant
    Filed: January 29, 2013
    Date of Patent: August 18, 2015
    Assignee: FUJITSU LIMITED
    Inventors: Yoshiaki Ohta, Yoshihiro Kawasaki, Kazuhisa Obuchi, Yoshiharu Tajima, Yoshinori Tanaka
  • Patent number: 9112560
    Abstract: A radio communication system that includes an encoder configured to perform error correction coding for control channel information by a given error correction coding rate and a modulator configured to perform modulation of the error correction coded control channel information for transmission according to a given modulation scheme, code decimation being performed for the error correction coded control channel information prior to the modulation, and the code decimation being different according to whether Multi Input Multi Output is applied or not.
    Type: Grant
    Filed: January 4, 2013
    Date of Patent: August 18, 2015
    Assignee: FUJITSU LIMITED
    Inventors: Kazuhisa Obuchi, Hideto Furukawa, Kazuo Kawabata, Yoshiharu Tajima, Yoshihiro Kawasaki
  • Patent number: 9100875
    Abstract: A reordering method of sending packets, to which numbers indicating the packet order are added, to a mobile station from a base station, and rearranging the order of the packets at the mobile station, this includes forwarding from a source base station to a target base station, packets, not sent to the mobile station before a handover sequence, or packets, a confirmation response of proper reception has not been received from the mobile station, transmitting preferentially those packets from the target base station to the mobile base station and then transmitting packets received from a host station to the mobile station, giving packets information indicating that the packets are jump packets when transmitting the packets to the mobile station, received from the host station with the order jumped, deciding jump packets are not objects of reordering, and performing the reordering process for packets that are objects of reordering.
    Type: Grant
    Filed: May 16, 2013
    Date of Patent: August 4, 2015
    Assignee: FUJITSU LIMITED
    Inventors: Yoshiaki Ohta, Yoshiharu Tajima, Kazuhisa Obuchi, Yoshihiro Kawasaki, Yoshinori Tanaka, Katsumasa Sugiyama
  • Patent number: 9094874
    Abstract: A radio communication system, that includes, a source base station; a target base station; and a mobile station in which the mobile station includes a receiving means for receiving first PDCP (Packet Data Convergence Protocol) PDU (Protocol Data Unit) and first sequence number from the source base station and a receiving means for receiving second PDCP PDU from the target base station, in which the second PDCP PDU being created using second sequence number and PDCP (Packet Data Convergence Protocol) SDU (Service Data Unit) that are transferred from the source base station to the target base station; a storage means for storing PDCP SDU corresponding to the first PDCP PDU and PDCP SDU corresponding to the second PDCP PDU; and a reordering means for performing in order delivery of the stored PDCP SDUs based on the first sequence number and the second sequence number.
    Type: Grant
    Filed: May 14, 2013
    Date of Patent: July 28, 2015
    Assignee: FUJITSU LIMITED
    Inventors: Yoshiaki Ohta, Yoshiharu Tajima, Kazuhisa Obuchi, Yoshihiro Kawasaki, Yoshinori Tanaka, Katsumasa Sugiyama
  • Patent number: 9094201
    Abstract: A wireless communication system including a sender apparatus having a plurality of transmitting antennas that performs MIMO transmission of a plurality of data blocks; and a receiver apparatus that receives the plurality of data blocks. The sender apparatus transmits a process number via a control channel different from a data channel to the receiver apparatus, and wherein when the MIMO diversity transmission is performed, the receiver apparatus performs HARQ processing in the received data blocks based on not a process number which prevents the data blocks from competing but the received process number from the sender apparatus.
    Type: Grant
    Filed: January 15, 2013
    Date of Patent: July 28, 2015
    Assignee: FUJITSU LIMITED
    Inventors: Yoshiaki Ohta, Kazuhisa Obuchi, Kazuo Kawabata, Yoshihiro Kawasaki, Yoshiharu Tajima, Hideto Furukawa
  • Patent number: 9094875
    Abstract: A mobile station that includes a receiving means for receiving first PDCP (Packet Data Convergence Protocol) PDU (Protocol Data Unit) to which a first sequence number is added from a source base station; a receiving means for receiving second PDCP PDU from a target base station that applies a second sequence number transferred from the source base station as a sequence number of PDCP (Packet Data Convergence Protocol) SDU (Service Data Unit) received from a host station and creates the second PDCP PDU and a storage means for storing PDCP SDU corresponding to the first PDCP PDU and PDCP SDU corresponding to the second PDCP PDU and means for performing in order delivery of the stored PDCP SDUs based on the sequence numbers corresponding to the PDCP SDUs.
    Type: Grant
    Filed: May 16, 2013
    Date of Patent: July 28, 2015
    Assignee: FUJITSU LIMITED
    Inventors: Yoshiaki Ohta, Yoshiharu Tajima, Kazuhisa Obuchi, Yoshihiro Kawasaki, Yoshinori Tanaka, Katsumasa Sugiyama
  • Patent number: 9094876
    Abstract: A reordering method of sending packets, to which numbers indicating the packet order are added, to a mobile station from a base station, and rearranging the order of the packets at the mobile station, this includes forwarding from a source base station to a target base station, packets, not sent to the mobile station before a handover sequence, or packets, a confirmation response of proper reception has not been received from the mobile station, transmitting preferentially those packets from the target base station to the mobile base station and then transmitting packets received from a host station to the mobile station, giving packets information indicating that the packets are jump packets when transmitting the packets to the mobile station, received from the host station with the order jumped, deciding jump packets are not objects of reordering, and performing the reordering process for packets that are objects of reordering.
    Type: Grant
    Filed: May 16, 2013
    Date of Patent: July 28, 2015
    Assignee: FUJITSU LIMITED
    Inventors: Yoshiaki Ohta, Yoshiharu Tajima, Kazuhisa Obuchi, Yoshihiro Kawasaki, Yoshinori Tanaka, Katsumasa Sugiyama
  • Patent number: 9055575
    Abstract: A base station in a mobile communication system containing a user equipment and the base station that includes an uplink (UL) resource management unit that allocates a plurality of parameters related to a physical uplink control channel (PUCCH) resource used for transmission processing, between the user equipment and the base station; a reception processing unit that receives a signal sent from the user equipment including a transmission processing unit that performs transmission processing based on transmission timing adjustment information; and a control unit that, if a valid term of first transmission timing adjustment information expires before transmission processing of a signal including identification information of the user equipment is performed during connection processing while performing the connection processing to the base station based on the first transmission timing adjustment information, aborts the connection processing and releases at least one of the allocated plurality of parameters rela
    Type: Grant
    Filed: April 12, 2013
    Date of Patent: June 9, 2015
    Assignee: FUJITSU LIMITED
    Inventors: Yoshiaki Ohta, Yoshiharu Tajima, Yutaka Kobayashi, Kazuhisa Obuchi
  • Patent number: 9055494
    Abstract: The present invention is a handover control method in a mobile communication system that performs handover control by switching base stations that communicate with a mobile terminal as the mobile terminal moves. In this handover control method, a mobile control device selects one or more handover base station candidates based on the communication state, and based on the communication capabilities of the handover base station candidates, decides a transmission rate for multicasting communication data, and transmits communication data to each of the handover base station candidates at the decided transmission rate, and a handover base station candidate that is decided as a handover base station sends the saved multicast communication data to the mobile terminal.
    Type: Grant
    Filed: May 26, 2010
    Date of Patent: June 9, 2015
    Assignee: Fujitsu Limited
    Inventors: Yoshiaki Ohta, Yoshiharu Tajima, Kazuo Kawabata
  • Patent number: 9049713
    Abstract: A radio communication apparatus selectively performs one of a first transmission method using for data transmission a radio resource which is assigned by a radio communication apparatus and which can be used on a contention basis by a plurality of radio communication apparatus and a second transmission method involving random access. Alternatively, the radio communication apparatus selectively performs one of the first transmission method and a third transmission method involving a request made to the radio communication apparatus to assign a radio resource for data transmission.
    Type: Grant
    Filed: December 1, 2014
    Date of Patent: June 2, 2015
    Assignee: FUJITSU LIMITED
    Inventors: Yoshiaki Ohta, Yoshihiro Kawasaki, Yoshiharu Tajima, Yoshinori Tanaka, Katsumasa Sugiyama
  • Patent number: 9042351
    Abstract: A radio communication system includes a mobile station configured to: intermittently receive information indicating a transmission format used for a shared channel via which data is received from a radio communication apparatus, intermittently transmit Channel Quality Indicator (CQI) information relating to the transmission format used for the shared channel in a first mode, set the timing of the intermittent transmission of the CQI information a given time before the reception of the information indicating a transmission format used for the shared channel, the CQI information being transmitted periodically, and switch from the first mode to a second mode in which the CQI information is transmitted more frequently than in the first mode; and the radio communication apparatus configured to communicate with the mobile station.
    Type: Grant
    Filed: November 25, 2013
    Date of Patent: May 26, 2015
    Assignee: FUJITSU LIMITED
    Inventors: Kazuhisa Obuchi, Hideto Furukawa, Kazuo Kawabata, Yoshiharu Tajima
  • Patent number: 9037177
    Abstract: A timing adjustment method in a mobile communication system that performs an adjustment of uplink transmission timing by random access between a user equipment and a base station, the timing adjustment method that includes performing transmission having transmission timing adjustment information in the user equipment; allocating a plurality of parameters related to a physical uplink control channel (PUCCH) resource used for communications, between the user equipment and the base station; and if a timer controlling a term of uplink transmission timing adjustment information expires during uplink communications to the base station having the uplink transmission timing adjustment information in the user equipment, releasing only a part of the allocated plurality of parameters related to the PUCCH resource.
    Type: Grant
    Filed: January 8, 2013
    Date of Patent: May 19, 2015
    Assignee: Fujitsu Limited
    Inventors: Yoshiaki Ohta, Yoshiharu Tajima, Yutaka Kobayashi, Kazuhisa Obuchi
  • Patent number: 9008674
    Abstract: A receiving apparatus includes a storing unit that stores therein notification information transmitted from a base station, a receiving unit that receives, from among the notification information transmitted by the base station, revision history of change information related to the notification information, and an updating unit that updates the notification information stored in the storing unit on the basis of the change information contained in the revision history received by the receiving unit.
    Type: Grant
    Filed: August 28, 2012
    Date of Patent: April 14, 2015
    Assignee: Fujitsu Limited
    Inventors: Kazuhisa Obuchi, Yoshiharu Tajima, Katsumasa Sugiyama
  • Patent number: 8995928
    Abstract: A first radio communication apparatus includes a controller and a transmitter. The controller determines timing capable of transmitting a control parameter used for a process for establishing connection to a second radio communication apparatus when the connection is not established between the first and second radio communication apparatus. The transmitter transmits a message including data different from the control parameter to the second radio communication apparatus at determined timing. The second radio communication apparatus includes a receiver and a data processing unit. The receiver receives from the first radio communication apparatus the message transmitted at timing at which the first radio communication apparatus is able to transmit the control parameter. The data processing unit extracts data included in the received message.
    Type: Grant
    Filed: December 3, 2012
    Date of Patent: March 31, 2015
    Assignee: Fujitsu Limited
    Inventors: Yoshiharu Tajima, Yoshinori Tanaka, Yoshihiro Kawasaki, Yoshiaki Ohta, Katsumasa Sugiyama, Kazuhisa Obuchi
  • Publication number: 20150087348
    Abstract: A radio communication apparatus selectively performs one of a first transmission method using for data transmission a radio resource which is assigned by a radio communication apparatus and which can be used on a contention basis by a plurality of radio communication apparatus and a second transmission method involving random access. Alternatively, the radio communication apparatus selectively performs one of the first transmission method and a third transmission method involving a request made to the radio communication apparatus to assign a radio resource for data transmission.
    Type: Application
    Filed: December 1, 2014
    Publication date: March 26, 2015
    Applicant: FUJITSU LIMITED
    Inventors: Yoshiaki OHTA, Yoshihiro KAWASAKI, Yoshiharu TAJIMA, Yoshinori TANAKA, Katsumasa SUGIYAMA
  • Publication number: 20150078339
    Abstract: A control method in a mobile communication system, that includes configuring a discard timer corresponding to a service data unit (SDU) for discarding the SDU according to a value of the discard timer that indicates a time elapsed since the discard timer started at reception of the SDU; when a handover is performed, maintaining the value of the discard timer corresponding to the SDU and taking over the elapsed time of the SDU; and discarding the corresponding SDU when the value of the discard timer reaches a given value.
    Type: Application
    Filed: November 21, 2014
    Publication date: March 19, 2015
    Applicant: FUJITSU LIMITED
    Inventors: Yoshiaki OHTA, Yoshiharu TAJIMA, Kazuhisa OBUCHI, Ryuichi TAKECHI, Naotoshi WATANABE, Yoshinori TANAKA, Katsumasa SUGIYAMA
  • Publication number: 20150031365
    Abstract: A mobile station includes a notifying unit configured to transmit a notification signal to a base station forming a serving cell, when a certain condition used to determine whether or not to perform a handover is satisfied, and a handover processing unit configured to start a handover process according to presence or absence of first communication data after transmission of the notification signal.
    Type: Application
    Filed: October 14, 2014
    Publication date: January 29, 2015
    Applicant: FUJITSU LIMITED
    Inventors: Yoshiharu Tajima, YOSHINORI TANAKA, Yoshiaki Ohta, Katsumasa SUGIYAMA
  • Publication number: 20150009837
    Abstract: In a radio communication system in which a radio communication apparatus performs communication with another apparatus via a radio relay apparatus, a communication quality value indicating communication quality between the radio communication apparatus and the radio relay apparatus is measured, a threshold for deciding a level of the communication quality is determined on the basis of a past tendency of the communication quality value, and transmission of contents between the radio communication apparatus and the other apparatus is blocked while a present value of the communication quality is smaller than the threshold.
    Type: Application
    Filed: June 19, 2014
    Publication date: January 8, 2015
    Inventors: Yoshiharu Tajima, Kazuaki Ando, Michiharu Nakamura, Yoshinori Tanaka