Patents by Inventor Kohei Kiyoshima

Kohei Kiyoshima 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: 20190159051
    Abstract: There is provided a base station of a radio communication system supporting carrier aggregation, the base station including a generator configured to generate configuration information indicating whether measurement requirements on reception quality are allowed to be relaxed with respect to a frequency of a predetermined secondary cell or with respect to the predetermined secondary cell, among a plurality of secondary cells, and a transmitter configured to transmit the configuration information to a user apparatus.
    Type: Application
    Filed: October 24, 2016
    Publication date: May 23, 2019
    Applicant: NTT DOCOMO, INC.
    Inventors: Hideaki Takahashi, Kunihiko Teshima, Kohei Kiyoshima, Kengo Yagyu
  • Publication number: 20190110305
    Abstract: A communication control method according to the present invention is implemented in a radio base station (200) including a remote device (260) and a central aggregation device (210) and that performs radio communication with a user device (300). The communication method includes acquiring including the remote device (260) acquiring via a predetermined uplink channel downlink quality information indicating radio communication quality in downlink acquired by the user device (300); transmitting including the remote device (260) transmitting to the central aggregation device (210) a quality data series containing one or more pieces of the downlink quality information acquired at the acquiring; and performing including the central aggregation device (210) performing assignment of a radio resource to the user device (300) based on the quality data series.
    Type: Application
    Filed: February 28, 2017
    Publication date: April 11, 2019
    Applicant: NTT DOCOMO, INC.
    Inventors: Naoto Ookubo, Kohei Kiyoshima, Anil Umesh, Tooru Uchino, Kazuki Takeda
  • Publication number: 20190053221
    Abstract: There is provided user equipment of a radio communication system provided with a base station and the user equipment, the user equipment including a reporting unit that reports, to the base station, a band combination supported by the user equipment, a MIMO layer number, and a modulation scheme, and a UE category supported by the user equipment; and a receiver that receives, upon detecting that a maximum bit rate that is achievable by carrier aggregation performed with the band combination supported by the user equipment, the MIMO layer number, and the modulation scheme exceeds a maximum bit rate to be supported by the UE category supported by the user equipment, data from the base station with a bit rate that is less than or equal to the maximum bit rate to be supported by the user equipment under the UE category.
    Type: Application
    Filed: January 11, 2017
    Publication date: February 14, 2019
    Applicant: NTT DOCOMO, INC.
    Inventors: Hideaki Takahashi, Tooru Uchino, Kohei Kiyoshima
  • Publication number: 20190037572
    Abstract: A mobile station which configures a plurality of component carriers to communicate with a base station is discloses herein including a reception unit configured to receive from the base station a gap pattern according to which a portion of an inter-frequency measurement duration is used for data communication and a communication control unit configured to control communication according to the gap pattern.
    Type: Application
    Filed: September 28, 2018
    Publication date: January 31, 2019
    Applicant: NTT DOCOMO, INC.
    Inventors: Hiroshi Chin, Hideaki Takahashi, Kengo Yagyu, Kohei Kiyoshima
  • Publication number: 20180343633
    Abstract: A base station used as a first base station in a radio communication system including the first base station, a second base station communicating via the first base station with a user device, and the user device communicating with the first base station. The base station includes a first receiver that receives an uplink signal transmitted from the user device; a measurer that measures a timing difference between a timing of receiving the uplink signal and a predetermined reference timing retained by the base station; and a first transmitter that transmits, to the user device, a command that is generated based on the timing difference and used to control a transmission timing at which the user device transmits the uplink signal.
    Type: Application
    Filed: August 29, 2016
    Publication date: November 29, 2018
    Applicant: NTT DOCOMO, INC.
    Inventors: Tooru UCHINO, Anil UMESH, Kohei KIYOSHIMA, Sadayuki ABETA
  • Publication number: 20180323931
    Abstract: A base station according to an embodiment is provided. The base station communicates with a user apparatus in an LTE-supported wireless communication system. The base station includes a generation unit configured to generate a signal in which a UE specific reference signal is mapped according to a first pattern in which, in a range of resource elements enclosed by a segment in the time direction indicated by a predetermined subframe in which a synchronization signal is mapped and by a segment in the frequency direction in which the synchronization signal is mapped, a UE specific reference signal is mapped onto a resource element other than a resource element onto which the synchronization signal is mapped; and a transmission unit configured to transmit the generated signal.
    Type: Application
    Filed: November 8, 2016
    Publication date: November 8, 2018
    Applicant: NTT DOCOMO, INC.
    Inventors: Kohei Kiyoshima, Naoto Ookubo, Sadayuki Abeta, Satoshi Nagata, Hiroki Harada
  • Patent number: 10117192
    Abstract: The present invention is designed so that mismatches in the recognition of TPC command-accumulated values between a radio base station and a user terminal are resolved in a simple way. The user terminal of the present invention provides a user terminal that transmits uplink channels, and that has a receiving section that receives transmission power control (TPC) commands from each of a plurality of cells that are grouped, a control section that controls the uplink channel transmission power of each of the multiple cells based on accumulated values of the TPC commands, and, when a reset condition is fulfilled in one of the multiple cells, the control section resets the accumulated values of all of the multiple cells.
    Type: Grant
    Filed: January 13, 2015
    Date of Patent: October 30, 2018
    Assignee: NTT DOCOMO, INC.
    Inventors: Kazuki Takeda, Tooru Uchino, Satoshi Nagata, Kohei Kiyoshima
  • Publication number: 20180279342
    Abstract: A base station used as a first base station in a wireless communication system including the first base station, a second base station that communicates with the first base station, and a user equipment that communicates with the first base station includes: a reception unit that receives a parameter used for generating a downlink physical data channel and data to be transmitted toward the user equipment from the second base station; a generating unit that generates the downlink physical data channel by performing processing of Layer 1 on the data using the parameter; and a transmission unit that transmits the generated downlink physical data channel.
    Type: Application
    Filed: January 17, 2017
    Publication date: September 27, 2018
    Applicant: NTT DOCOMO, INC.
    Inventors: Takahiro Takiguchi, Kohei Kiyoshima, Satoshi Nagata
  • Publication number: 20180241500
    Abstract: A user terminal includes a receiver that receives a downlink shared channel and a processor that obtains a transport block size (TBS) used for the downlink shared channel based on: a TBS index value that is associated with a modulation and coding scheme (MCS) index value used for the downlink shared channel; and a number of resource blocks (RBs) that are allocated to the downlink shared channel. When the downlink shared channel is transmitted by a predetermined transmission scheme and the MCS index value is a predetermined value, the processor modifies the TBS index value associated with the predetermined value and obtains the TBS based on the modified TBS index value and the number of RBs.
    Type: Application
    Filed: August 8, 2016
    Publication date: August 23, 2018
    Applicant: NTT DOCOMO, INC.
    Inventors: Kazuaki Takeda, Satoshi Nagata, Kohei Kiyoshima, Hideaki Takahashi, Sadayuki Abeta
  • Patent number: 10028315
    Abstract: A user apparatus configured to perform discontinuous reception control for discontinuously receiving a signal transmitted from a base station, including: a reception unit configured to receive information, from the base station, specifying a transmission cycle of a control signal in discontinuous reception performed at a predetermined discontinuous reception cycle; and a transmission control unit configured, when performing the discontinuous reception at the predetermined discontinuous reception cycle, to transmit the control signal in an active period in the discontinuous reception at a cycle longer than the discontinuous reception cycle based on the information specifying the transmission cycle.
    Type: Grant
    Filed: December 16, 2014
    Date of Patent: July 17, 2018
    Assignee: NTT DOCOMO, INC.
    Inventors: Tooru Uchino, Kohei Kiyoshima
  • Patent number: 10020873
    Abstract: Even in the case of satellite communications to which LTE is applied, a difference between reception timings of uplink singles transmitted from a plurality of mobile stations UE located in the same cell is kept within GI specified in LTE. A mobile station UE#1 according to the present invention includes: an offset calculation unit 23 configured to calculate an offset ? from a transmission timing to be referenced, based on a distance Lx between the mobile station UE#1 and a satellite 1 used in satellite communications, and a distance Lref between the satellite 1 and a reference mobile station UE; and an RACH functional unit 24 configured to adjust a transmission timing of a random access preamble based on the calculated offset ?.
    Type: Grant
    Filed: July 18, 2014
    Date of Patent: July 10, 2018
    Assignee: NTT DOCOMO, INC.
    Inventors: Tooru Uchino, Yoshiaki Ofuji, Kohei Kiyoshima
  • Patent number: 9986536
    Abstract: To execute appropriate process when “Time-Switched UL CA” is executed and even when transmission of uplink information using a plurality of CCs has been scheduled in a same TTI. A radio base station eNB according to the present invention includes a UL transmission processing unit 11 configured to transmit uplink information at TTI#n+4 using a CC allocated over a PDCCH to the mobile station UE at TTI#n. The UL transmission processing unit 11 is configured to transmit the uplink information at each of TTIs using only one CC, and when a plurality of CCs is allocated at TTI#n, the UL transmission processing unit 11 is configured to select uplink information to be transmitted at TTI#n+4, based on a priority corresponding to the uplink information to be transmitted using each of the plurality of CCs allocated.
    Type: Grant
    Filed: July 5, 2013
    Date of Patent: May 29, 2018
    Assignee: NTT DOCOMO, INC.
    Inventors: Tooru Uchino, Hideaki Takahashi, Yuta Sagae, Kohei Kiyoshima, Kazuaki Takeda
  • Publication number: 20180139750
    Abstract: A user apparatus configured to perform communication with a base station in a mobile communication system that supports carrier aggregation, including: transmission means configured to transmit, to the base station, the number of layers for each of component carriers that form the carrier aggregation as information of downlink MIMO capability; and reception means configured to receive, from the base station, the number of layers that is used for determining a bit width of a rank indicator for each of the component carriers that form the carrier aggregation.
    Type: Application
    Filed: June 9, 2016
    Publication date: May 17, 2018
    Applicant: NTT DOCOMO, INC.
    Inventors: Hideaki Takahashi, Kohei Kiyoshima, Takahiro Takiguchi, Masaaki Ohtake
  • Publication number: 20180109971
    Abstract: The present invention is designed to optimize the uplink random access procedure even when coverage enhancement is applied to communication by user terminals, in which the bandwidth for use is limited to partial reduced bandwidths in a system bandwidth. A user terminal, in which the bandwidth to use is limited to a partial reduced bandwidth in a system bandwidth, has a receiving section that receives information related to repetitious transmission of a PRACH (Physical Random Access CHannel); and a transmission section that transmits the PRACH in repetitions in part or all of subframes based on the information related to repetitious transmission.
    Type: Application
    Filed: April 8, 2016
    Publication date: April 19, 2018
    Applicant: NTT DOCOMO, INC.
    Inventors: Kazuaki Takeda, Kohei Kiyoshima, Shimpei Yasukawa, Satoshi Nagata
  • Patent number: 9906976
    Abstract: A mobile station UE notifies a radio base station of a total amount of data accumulated in a buffer with granularity finer than an LCG. A mobile station UE according to the present invention includes: a management unit 11 configured to manage LCGs and manage DFGs each of which is a group of one or more priorities assigned to one or more data flows; and a transmission unit 13 configured to notify a radio base station eNB of a total amount of data remaining in a buffer for each of combinations of the LCGs and DFGs.
    Type: Grant
    Filed: March 20, 2014
    Date of Patent: February 27, 2018
    Assignee: NTT DOCOMO, INC.
    Inventors: Tooru Uchino, Hideaki Takahashi, Wuri Andarmawanti Hapsari, Kohei Kiyoshima
  • Patent number: 9781705
    Abstract: In order to control feedback control information in uplink transmission appropriately even when using carrier aggregation in HetNet, the present invention provides a user terminal that is able to communicate with a plurality of radio base stations having overlapping coverage areas by using carrier aggregation, the user terminal comprising: a reception section that receives downlink shared channel signals using component carriers of a primary cell and a secondary cell; a generating section that generates transmission acknowledgement signals in response to the downlink shared channel signals; and an allocating section that allocates the transmission acknowledgement signals to predetermined uplink control channel resources, wherein the allocating section allocates the transmission acknowledgement signals to either or both of uplink control channel resources of the primary cell and uplink control channel resources of the secondary cell in accordance with contents of the transmission acknowledgement signals and/or
    Type: Grant
    Filed: November 12, 2013
    Date of Patent: October 3, 2017
    Assignee: NTT DOCOMO, INC.
    Inventors: Kazuaki Takeda, Yoshihisa Kishiyama, Kohei Kiyoshima, Tooru Uchino, Yuta Sagae, Hideaki Takahashi
  • Publication number: 20170264398
    Abstract: There is provided a terminal for communicating with a base station apparatus, the terminal including a receiver that receives, from the base station apparatus, instruction information for performing an operation of an error correction process to be executed between the base station apparatus and the terminal, the instruction information including at least one of a process number of a process to be used for the error correction process, a time from receiving a signal until transmitting a reception response, and a timer value indicating a time from receiving the signal until receiving a retransmitted signal; and a processor that executes the error correction process based on the instruction information received by the receiver.
    Type: Application
    Filed: January 27, 2016
    Publication date: September 14, 2017
    Applicant: NTT DOCOMO, INC.
    Inventors: Tooru Uchino, Kazuki Takeda, Kohei Kiyoshima
  • Patent number: 9749998
    Abstract: A radio communication method of a user terminal and a radio base station adopting carrier aggregation to adequately feed back channel state information of a plurality of cells from a user terminal to a radio base station, is disclosed. The user generates channel state information of each cell in uplink control channel format 2 or in format 3 based on the number of cells to use in carrier aggregation, feeds back the generated channel state information via resources that the radio base station sets in an uplink control channel of a primary cell at a predetermined time in accordance with an uplink control channel format, and the radio base station secures the resources to set in the uplink control channel when the channel state information of the primary cell is generated in uplink control channel format 2, regardless of the number of cells to use in carrier aggregation.
    Type: Grant
    Filed: July 26, 2013
    Date of Patent: August 29, 2017
    Assignee: NTT DOCOMO, INC.
    Inventors: Kazuaki Takeda, Yoshihisa Kishiyama, Kohei Kiyoshima, Satoshi Nagata
  • Publication number: 20170099635
    Abstract: The present invention is designed to reduce the power consumption of user terminals more in comparison to conventional DRX control. The present invention provides a receiving section, which receives a DL signal including at least a UL grant, and a DRX control section, which controls the discontinuous reception operations, and the DRX control section, when receiving the DL signal including a UL grant, controls the discontinuous reception operations based on the DRX transition command information that is included in the DL signal. Also, a command for a transition to the discontinuous reception state is transmitted by using downlink control information that includes a UL grant, or a MAC control element.
    Type: Application
    Filed: May 8, 2015
    Publication date: April 6, 2017
    Applicant: NTT DOCOMO, INC.
    Inventors: Tooru Uchino, Kohei Kiyoshima
  • Publication number: 20170034870
    Abstract: A user apparatus configured to perform discontinuous reception control for discontinuously receiving a signal transmitted from a base station, including: a reception unit configured to receive information, from the base station, specifying a transmission cycle of a control signal in discontinuous reception performed at a predetermined discontinuous reception cycle; and a transmission control unit configured, when performing the discontinuous reception at the predetermined discontinuous reception cycle, to transmit the control signal in an active period in the discontinuous reception at a cycle longer than the discontinuous reception cycle based on the information specifying the transmission cycle.
    Type: Application
    Filed: December 16, 2014
    Publication date: February 2, 2017
    Applicant: NTT DOCOMO, INC.
    Inventors: Tooru Uchino, Kohei Kiyoshima