Patents by Inventor Kazuhisa Obuchi

Kazuhisa Obuchi 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: 9295005
    Abstract: A radio communication apparatus transmitting a data signal and a control signal to another radio communication apparatus where a controller controls transmission power of the control signal separately from transmission power of the data signal based on a feedback signal from the other radio communication apparatus. A method for controlling transmission power of a control channel includes determining a transmission power of a control channel based on a response from user equipment and controlling transmission power of the control channel separately from transmission power of a data signal based on the determined transmission power of a control channel.
    Type: Grant
    Filed: December 27, 2006
    Date of Patent: March 22, 2016
    Assignee: FUJITSU LIMITED
    Inventors: Kazuhisa Obuchi, Tetsuya Yano
  • Patent number: 9288014
    Abstract: A communication apparatus that performs receiving processing of data transmitted at timings of a predetermined interval, the communication apparatus includes: a transmitting unit configured to transmit a signal indicating that data is successfully received when the data transmitted at Mth timing according to the predetermined interval is successfully received; and a control unit configured to determine whether or not a retransmission control processing is performed when the signal indicating that the data is successfully received is transmitted, wherein the control unit transmits a signal indicating that the data is successfully received when the retransmission control processing is performed.
    Type: Grant
    Filed: November 26, 2013
    Date of Patent: March 15, 2016
    Assignee: FUJITSU LIMITED
    Inventors: Kazuhisa Obuchi, Yoshihiro Kawasaki, Yoshiharu Tajima, Yoshiaki Ohta, Yoshinori Tanaka, Katsumasa Sugiyama
  • Patent number: 9265014
    Abstract: In order to properly expel one or more mobile terminals from a cell that a wireless base station is accommodating, the management station includes at least one processor configured to obtain, for each of the plurality of mobile terminals, speed data indicating a moving speed of the mobile terminal; select one or more mobile terminals each having a moving speed, indicated by the speed data, satisfying a first criterion among the plurality of mobile terminals; and control the wireless base station such that the selected mobile terminals are out of communication with the cell.
    Type: Grant
    Filed: January 24, 2013
    Date of Patent: February 16, 2016
    Assignee: FUJITSU LIMITED
    Inventors: Kazuhisa Obuchi, Eisuke Fukuda
  • Patent number: 9253687
    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: October 21, 2009
    Date of Patent: February 2, 2016
    Assignee: FUJITSU LIMITED
    Inventors: Yoshiaki Ohta, Yoshiharu Tajima, Kazuhisa Obuchi, Yoshihiro Kawasaki, Yoshinori Tanaka, Katsumasa Sugiyama
  • Patent number: 9204348
    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: Grant
    Filed: November 21, 2014
    Date of Patent: December 1, 2015
    Assignee: FUJITSU LIMITED
    Inventors: Yoshiaki Ohta, Yoshiharu Tajima, Kazuhisa Obuchi, Ryuichi Takechi, Naotoshi Watanabe, Yoshinori Tanaka, Katsumasa Sugiyama
  • Patent number: 9198086
    Abstract: In a mobile communication system, a relay station connects to a first or second base station, and communicates with a mobile station at a timing corresponding to the destination base station. Before execution of a handover for switching a destination of the relay station from the first base station to the second base station, the relay station transmits a signal regarding the second base station. The mobile station synchronizes with the relay station after execution of the handover, on the basis of the signal regarding the second base station which is received from the relay station before the handover.
    Type: Grant
    Filed: April 3, 2013
    Date of Patent: November 24, 2015
    Assignee: FUJITSU LIMITED
    Inventors: Kazuhisa Obuchi, Yoshihiro Kawasaki, Yoshiaki Ohta
  • Patent number: 9191089
    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; a modulator configured to perform modulation of the error correction coded control channel information for transmission according to a given modulation scheme; and a processing section configured to perform code decimation of the error correction coded control channel information prior to the modulation, the code decimation being different according to whether the Multi Input Multi Output is applied or not.
    Type: Grant
    Filed: November 21, 2012
    Date of Patent: November 17, 2015
    Assignee: FUJITSU LIMITED
    Inventors: Kazuhisa Obuchi, Hideto Furukawa, Kazuo Kawabata, Yoshiharu Tajima, Yoshihiro Kawasaki
  • Patent number: 9191933
    Abstract: A mobile communication system having a user equipment that performs transmission process having transmission timing adjustment information and a base station that receives a signal sent from the user equipment, the mobile communication system includes, if a timer controlling a term of application of first transmission timing adjustment information expires before transmission of a signal including identification information of the user equipment is performed during a connection process including reception of second transmission timing adjustment information while the user equipment has the first transmission timing adjustment information and performing the connection process to the base station, the user equipment does not transmit the signal.
    Type: Grant
    Filed: January 8, 2013
    Date of Patent: November 17, 2015
    Assignee: FUJITSU LIMITED
    Inventors: Yoshiaki Ohta, Yoshiharu Tajima, Yutaka Kobayashi, Kazuhisa Obuchi
  • Publication number: 20150312909
    Abstract: A relay station which performs radio communications with a base station and a mobile station, the relay station includes: a receiver configured to receive radio signals from the base station in downlink backhaul subframes, and to limit reception of radio signals from the base station in subframes other than the downlink backhaul subframes; and a controller configured to allow, when performing a random access to the base station, the receiver to receive a message of the random access even in the subframes other than the downlink backhaul subframes.
    Type: Application
    Filed: July 7, 2015
    Publication date: October 29, 2015
    Inventors: Yoshiaki OHTA, Yoshihiro KAWASAKI, Kazuhisa OBUCHI, Yoshiharu TAJIMA, Yoshinori TANAKA
  • 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
  • Publication number: 20150280807
    Abstract: A wireless communication system includes a wireless base station, a mobile station configured to communicate with the wireless base station, and a relay station configured to relay the communication between the wireless base station and the mobile station. When the number of the mobile stations communicating with the wireless base station is judged to have become smaller than or equal to a given number, a power controller in the relay station executes at least one of power control to cut off the power for relaying the communication, power control to perform intermittent operation, and power control to perform power-saving operation.
    Type: Application
    Filed: June 10, 2015
    Publication date: October 1, 2015
    Inventors: Takayoshi ODE, 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: 9100965
    Abstract: A communication apparatus includes an acquisition unit that acquires a size of free space provided in each of a plurality of data transmission units of a first layer; an allocation unit that allocates to data of a second layer a contiguous sequence of free space from among the free space whose size is acquired by the acquisition unit, the contiguous sequence of free space being equal in size to the data of the second layer and provided in one data transmission unit of the first layer; and a multiplexing unit that multiplexes a plurality of pieces of data of the second layer into the plurality of data transmission units of the first layer according to the allocation of the free space by the allocation unit.
    Type: Grant
    Filed: February 4, 2014
    Date of Patent: August 4, 2015
    Assignee: FUJITSU LIMITED
    Inventors: Chiaki Shinohara, Kazuhisa Obuchi, Akihide Otonari, Yoshinori Soejima, Manabu Kubota, Miki Yamasaki, Shinya Okamoto
  • 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