Patents by Inventor Tetsushi Abe

Tetsushi Abe 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: 10064161
    Abstract: To provide a user terminal, radio base station apparatus, radio communication system and radio communication method that support increases in the number of users, a user terminal is provided with a reception section that receives a downlink control signal multiplexed into radio resources from the starting OFDM symbol to a predetermined OFDM symbol in a subframe, and a downlink control signal subjected to frequency division multiplexing with a downlink data signal into radio resources after the predetermined OFDM symbol, a retransmission check section that performs a retransmission check on the downlink data signal based on the downlink control signal subjected to frequency division multiplexing to output a retransmission response signal, and a selection section that selects a radio resource of an uplink control channel used in transmission of the retransmission response signal.
    Type: Grant
    Filed: February 17, 2012
    Date of Patent: August 28, 2018
    Assignee: NTT DOCOMO, INC.
    Inventors: Kazuaki Takeda, Tetsushi Abe, Yoshihisa Kishiyama, Satoshi Nagata
  • Patent number: 10064216
    Abstract: To enable a mobile terminal apparatus to correctly demodulate a data signal in the case of applying Coordinated Multi-Point transmission (CoMP), particularly, JP-CoMP, a radio communication method of the invention is characterized in that a radio base station apparatus generates information for demodulation of a data signal in a mobile terminal apparatus in applying Coordinated Multi-Point transmission, and transmits the information for demodulation to a mobile terminal apparatus that performs Coordinated Multi-Point reception, and that the mobile terminal apparatus receives the information for demodulation of a data signal, and demodulates the data signal subjected to Coordinated Multi-Point reception using the information for demodulation.
    Type: Grant
    Filed: April 24, 2012
    Date of Patent: August 28, 2018
    Assignee: NTT DOCOMO, INC.
    Inventors: Satoshi Nagata, Tetsushi Abe, Yoshihisa Kishiyama, Kazuaki Takeda
  • Patent number: 9832766
    Abstract: A radio communication method for a radio base station, apparatus that controls transmission of an aperiodic SRS (Sounding Reference Signal) by a mobile terminal apparatus is described. The radio communication method includes selecting a specific bit information piece to report to the mobile terminal apparatus, from a table having four bit in formation pieces including one bit information piece to indicate not to trigger the aperiodic SRS and three bit information pieces to indicate to transmit the aperiodic SRS using first to third default SRS parameters respectively, the four bit information pieces all being defined in a 2-bit bit field in downlink control information to be transmitted in one subframe, and transmitting, to the mobile terminal apparatus; the first to third default SRS parameters by higher layers and the specific bit information piece by a downlink control channel.
    Type: Grant
    Filed: January 6, 2017
    Date of Patent: November 28, 2017
    Assignee: NTT DOCOMO, INC.
    Inventors: Daisuke Nishikawa, Kazuaki Takeda, Tetsushi Abe, Yoshihisa Kishiyama
  • Patent number: 9806834
    Abstract: The present invention is designed such that it is possible to optimize the effect of improving the efficiency of use of radio resources even when the number of user terminals to be multiplexed over the same radio resources is further increased. A user terminal performs downlink communication with a radio base station using a PDCCH resource region and a PDSCH resource region. The user terminal detects the starting position of the radio resources where the PDSCH and the PDCCH are frequency-division-multiplexed in the PDSCH resource region in the time direction, and receives the PDCCH that is frequency-division-multiplexed over the radio resources starting from the detected starting position.
    Type: Grant
    Filed: April 24, 2012
    Date of Patent: October 31, 2017
    Assignee: NTT DOCOMO, INC.
    Inventors: Satoshi Nagata, Tetsushi Abe, Yoshihisa Kishiyama, Kazuaki Takeda
  • Patent number: 9756633
    Abstract: The present invention is designed to provide a radio base station apparatus, a mobile terminal apparatus, a radio communication system and a radio communication method which can cope with an increased number of users. A radio base station apparatus is provided with: a signal generating section that generates a first downlink control signal and a second downlink control signal for a mobile terminal apparatus; a first multiplexing section that multiplexes the first downlink control signal on a control region up to a predetermined number of symbols from the top of a subframe; a second multiplexing section that frequency-division-multiplexes the second downlink control signal on radio resources from the next symbol in the control region to the last symbol of the subframe; and a transmission section that transmits the first downlink control signal multiplexed on the control region and the second downlink control signal multiplexed on the radio resources.
    Type: Grant
    Filed: April 21, 2016
    Date of Patent: September 5, 2017
    Assignee: NTT DOCOMO, INC.
    Inventors: Tetsushi Abe, Yoshihisa Kishiyama, Satoshi Nagata, Nobuhiko Miki, Kazuaki Takeda
  • Patent number: 9743384
    Abstract: The present invention provides a base station apparatus, a mobile terminal apparatus and a communication control method which can improve the accuracy of channel quality estimation. A communication control method includes the steps of: allocating a CSI-RS (Channel State Information-Reference Signal), which is a reference signal for downlink channel estimation, in resources for the CSI-RS that are defined for CSI-RS transmission; setting muting resources in the resources for the CSI-RS; and reporting parameters to specify the CSI-RS, including at least a transmitting subframe cycle, a subframe offset and transmission power, to a mobile terminal apparatus.
    Type: Grant
    Filed: October 3, 2011
    Date of Patent: August 22, 2017
    Assignee: NTT DOCOMO, INC.
    Inventors: Satoshi Nagata, Yusuke Ohwatari, Tetsushi Abe, Nobuhiko Miki
  • Patent number: 9723569
    Abstract: The present invention is designed to provide a radio communication system which can control uplink transmission power adequately even in an HetNet environment.
    Type: Grant
    Filed: July 20, 2012
    Date of Patent: August 1, 2017
    Assignee: NTT DOCOMO, INC.
    Inventors: Daisuke Nishikawa, Satoshi Nagata, Tetsushi Abe
  • Patent number: 9716578
    Abstract: The present invention is designed to minimize the increase of user terminal power consumption even when downlink control channels are extended.
    Type: Grant
    Filed: July 13, 2012
    Date of Patent: July 25, 2017
    Assignee: NTT DOCOMO, INC.
    Inventors: Kazuaki Takeda, Tetsushi Abe, Yoshihisa Kishiyama, Satoshi Nagata, Daisuke Nishikawa
  • Publication number: 20170171843
    Abstract: A base station apparatus capable of transmitting a downlink transmission frame at transmission timing different from another base station apparatus is provided. The base station apparatus includes a blank resource setting section that sets, as a blank resource, a resource corresponding to a downlink control channel included in a downlink transmission frame transmitted from the other base station apparatus, a user data assigning section that assigns user data to the downlink transmission frame while avoiding the blank resource, and a transmission section that transmits the downlink transmission frame assigned the user data to a mobile terminal apparatus.
    Type: Application
    Filed: February 14, 2017
    Publication date: June 15, 2017
    Applicant: NTT DOCOMO, INC.
    Inventors: Tetsushi Abe, Satoshi Nagata, Nobuhiko Miki, Sangiamwong Jaturong
  • Patent number: 9680537
    Abstract: The present invention is designed to reduce the increase in the amount of the calculation process in a mobile station and the amount of CSI feedback data, and also prevent the amount of overall system capacity from decreasing. This radio communication system (1) has a radio base station (200) which can form a plurality of beams that are vertically sectorized. The radio base station (200), using an array antenna (10), forms at least the first beam that is directed to the cell edge side and a second beam that is directed to the cell center side, in parallel. A mobile station (100) measures channel quality by extracting reference signals from each of the first beam and the second beam, generates a communication quality feedback signal including channel quality measured from at least one of the beams, and feeds this back to the radio base station (200) via the uplink.
    Type: Grant
    Filed: August 14, 2012
    Date of Patent: June 13, 2017
    Assignee: NTT DOCOMO , INC.
    Inventors: Yuki Inoue, Tetsushi Abe
  • Patent number: 9681443
    Abstract: A radio base station apparatus that reports SRS (Sounding Reference Signal) transmission control information to a mobile terminal apparatus and controls transmission of an SRS by the mobile terminal apparatus is described. The radio base station includes an SRS setting section configured to select bit information to report to the mobile terminal apparatus, from a table having bit information to indicate not to trigger the SRS and bit information to indicate to trigger the SRS using a default SRS parameter and a reporting section configured to report the bit information for the mobile terminal apparatus using a downlink control channel.
    Type: Grant
    Filed: December 2, 2014
    Date of Patent: June 13, 2017
    Assignee: NTT DOCOMO, INC.
    Inventors: Daisuke Nishikawa, Kazuaki Takeda, Tetsushi Abe, Yoshihisa Kishiyama
  • Patent number: 9655098
    Abstract: The present invention is designed to reduce interference from a macro base station to a small transmission power node. The present invention is characterized in providing a micro base station which forms, in a macro cell where a macro base station transmits a signal to a macro terminal, a micro cell where the micro base station transmits a signal to a micro terminal under control with low power, and this micro base station generates a PDCCH which includes downlink or uplink resource allocation information, and, in a non-transmission period in which the macro base station stops transmitting signals while leaving minimal quality measurement signals, shifts the transmission starting symbol of the PDCCH to a position where the PDCCH does not overlap the quality measurement signals.
    Type: Grant
    Filed: March 16, 2016
    Date of Patent: May 16, 2017
    Assignee: NTT DOCOMO, INC.
    Inventors: Tetsushi Abe, Satoshi Nagata, Kazuaki Takeda
  • Publication number: 20170127389
    Abstract: A radio communication method for a radio base station, apparatus that controls transmission of an aperiodic SRS (Sounding Reference Signal) by a mobile terminal apparatus is described. The radio communication method includes selecting a specific bit information piece to report to the mobile terminal apparatus, from a table having four bit in formation pieces including one bit information piece to indicate not to trigger the aperiodic SRS and three bit information pieces to indicate to transmit the aperiodic SRS using first to third default SRS parameters respectively, the four bit information pieces all being defined in a 2-bit bit field in downlink control information to be transmitted in one subframe, and transmitting, to the mobile terminal apparatus; the first to third default SRS parameters by higher layers and the specific bit information piece by a downlink control channel.
    Type: Application
    Filed: January 6, 2017
    Publication date: May 4, 2017
    Applicant: NTT DOCOMO, INC.
    Inventors: Daisuke Nishikawa, Kazuaki Takeda, Tetsushi Abe, Yoshihisa Kishiyama
  • Patent number: 9629149
    Abstract: It is an object of the present invention to adequately report the SRS transmission timing and SRS parameters to a mobile terminal apparatus, when an aperiodic SRS is adopted, and efficiently use radio resources to be used for SRS transmission. A radio base station apparatus that reports SRS transmission control information to a mobile terminal apparatus and controls transmission of an SRS by the mobile terminal apparatus, and the radio base station apparatus has an SRS setting section that selects bit information to report to the mobile terminal apparatus, from a table having bit information to indicate not to trigger the SRS and bit information to indicate to trigger the SRS using a default SRS parameter, and a reporting section that reports the bit information for the mobile terminal apparatus using a downlink control channel.
    Type: Grant
    Filed: October 3, 2011
    Date of Patent: April 18, 2017
    Assignee: NTT DOCOMO, INC.
    Inventors: Daisuke Nishikawa, Kazuaki Takeda, Tetsushi Abe, Yoshihisa Kishiyama
  • Patent number: 9591628
    Abstract: In order to reduce radio resources allocated to PDCCHs and improve the data rate even when a plurality of component carriers are aggregated into a wide band, the present invention provides a base station apparatus having: a downlink control information generation section (306) configured to generate downlink control information (DCI) to demodulate PDSCHs that are sent independently in respective component carriers (CCs) allocated to a user terminal; and a transmitting section configured to transmit a PDCCH containing the downlink control information (DCI). The downlink control information (DCI) generated by the downlink control information generation section (306) is added with identification information (CIF) that is used to demodulate the PDSCHs assigned to the component carriers and is capable of identifying each of the component carriers.
    Type: Grant
    Filed: June 14, 2011
    Date of Patent: March 7, 2017
    Assignee: NTT DOCOMO, INC.
    Inventors: Nobuhiko Miki, Tetsushi Abe, Kazuaki Takeda
  • Patent number: 9521604
    Abstract: In order to transmit a paging to a user terminal with high quality, transmit a CSI-RS effectively and perform UL HARQ efficiently in HetNet, the present invention provides a radio communication method having the steps of: a micro base station which is arranged in a macro cell and forms a smaller micro cell than the macro cell, transmitting, to a user terminal, a signal having a CSI-RS subframe including a CSI-RS and a paging subframe including modification notification information indicating modification in system information and a control signal indicating not to measure a CSI-RS when the CSI-RS subframe and the paging subframe collide with each other; and the user terminal determining a CSI-RS subframe to measure the CSI-RS based on the control signal when the CSI-RS subframe and the paging subframe collide with each other.
    Type: Grant
    Filed: November 8, 2011
    Date of Patent: December 13, 2016
    Assignee: NTT DOCOMO, INC.
    Inventors: Tetsushi Abe, Satoshi Nagata, Nobuhiko Miki, Naoto Ookubo
  • Patent number: 9497676
    Abstract: A user equipment 10 according to the present invention is provided with a RSSI measuring unit 107 that, with regard to a predetermined sub-frame, is configured to measure a radio quality of a serving cell and a neighboring cell for all OFDM symbols within the predetermined sub-frame and that, with regard to sub-frames other than the predetermined sub-frame, is configured to measure the radio quality of the serving cell and the neighboring cell for OFDM symbols containing a reference signal within the sub-frames.
    Type: Grant
    Filed: January 11, 2012
    Date of Patent: November 15, 2016
    Assignee: NTT DOCOMO, INC.
    Inventors: Hiroyuki Ishii, Daisuke Nishikawa, Tetsushi Abe
  • Patent number: 9485775
    Abstract: The present invention is designed to execute adequate signaling even when individual user terminals perform communication to support separate types of communication, in MIMO transmission to use antennas having varying antenna configurations depending on the type of communication. A radio base station (200) has an antenna that has varying antenna configurations between at least two types of communication and that can transmit signals to all areas which the radio base station covers, in an antenna configuration to support at least one communication type 1, allocates radio resources to a downlink signal including capacities of a user terminal and a signal type to match a communication type, multiplexes a plurality of reference signals to be used in each communication type on the same resource block, generates precoding weights which allow the antenna to form a number of beams to match the communication type, and multiplies a downlink signal to supply to the antenna by the generated precoding weights.
    Type: Grant
    Filed: August 15, 2012
    Date of Patent: November 1, 2016
    Assignee: NTT DOCOMO, INC.
    Inventors: Yuki Inoue, Tetsushi Abe
  • Patent number: 9473996
    Abstract: A communication control device includes a parameter acquisition unit which acquires a first parameter determined on the basis of the number of mobile stations connected to the first cell or the number of mobile stations connected to the second cell, a parameter determination unit which changes the number of mobile stations connectable to the first cell or the number of mobile stations connectable to the second cell on the basis of the first parameter, and a parameter notification unit which notifies at least any one of the first base station and the second base station of the determined second parameter.
    Type: Grant
    Filed: May 21, 2012
    Date of Patent: October 18, 2016
    Assignee: NTT DOCOMO, INC.
    Inventors: Satoshi Nagata, Tetsushi Abe, Hideaki Takahashi, Mikio Iwamura, Takehiro Nakamura
  • Patent number: 9467271
    Abstract: Provided are a radio base station apparatus, a mobile terminal apparatus and a radio communication method capable of taking other-cell interference mitigation measures even in consideration of inter-cell coordination like CoMP. The radio communication method according to the present invention is characterized by, in a radio base station apparatus, generating notification information including subframe information of a serving cell and subframe information of another cell; and transmitting the notification information to a mobile terminal apparatus connected to the serving cell as a connected cell; and in the mobile terminal apparatus, receiving the notification information including the subframe information of the connected cell and the subframe information of another cell; and measuring channel quality of the connected cell with use of the subframe information of the connected cell and measuring channel quality of another cell with use of the subframe information of another cell.
    Type: Grant
    Filed: November 6, 2015
    Date of Patent: October 11, 2016
    Assignee: NTT DOCOMO, INC.
    Inventors: Satoshi Nagata, Tetsushi Abe