Patents by Inventor Naoto Ookubo

Naoto Ookubo 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: 9232507
    Abstract: To efficiently detect feedback control information on downlink shared data channel signals transmitted with a plurality of base frequency blocks also in the case of performing radio communications with a system band comprised of a plurality of base frequency blocks, it is a feature to have detecting sections (208, 210) configured to detect a correlation value between an ACK/NACK signal received in uplink and each of ACK/NACK candidate replicas associated with ACK and NACK in response to a downlink shared data channel signal of a particular base frequency block assigned to the mobile terminal apparatus among a plurality of base frequency blocks or of each of a plurality of base frequency blocks, and an A/N·DTX determining section (211) configured to determine feedback control information on the downlink shared data channel signal of the particular base frequency block or of each of the plurality of base frequency blocks, based on the detected correlation value and a DTX determination threshold value.
    Type: Grant
    Filed: October 3, 2011
    Date of Patent: January 5, 2016
    Assignee: NTT DOCOMO, INC.
    Inventors: Kazuaki Takeda, Naoto Ookubo, Tetsushi Abe, Yoshihisa Kishiyama
  • Patent number: 9220021
    Abstract: A user apparatus transmits an uplink control signal to a base station apparatus using a single carrier scheme. The user apparatus includes: a unit configured to prepare acknowledgement information indicating positive acknowledgement or negative acknowledgement for a downlink data signal based on a result of demodulation of the downlink data signal; a unit configured to prepare channel state information indicating reception quality of a downlink reference signal; a unit configured to channel-code multiplexed control information in which the acknowledgement information and the channel state information are multiplexed to prepare the uplink control signal; and a unit configured to transmit the uplink control signal using dedicated resources different from resources for an uplink data signal.
    Type: Grant
    Filed: March 5, 2013
    Date of Patent: December 22, 2015
    Assignee: NTT DOCOMO, INC.
    Inventors: Naoto Ookubo, Hiroyuki Ishii, Nobuhiko Miki, Kenichi Higuchi, Yoshihisa Kishiyama
  • Patent number: 9107111
    Abstract: In order to assure reception of broadcast information by a user terminal handed over to a micro base station by CRE (Cell Range Expansion) and to reduce the number of transmission stopped subframes in a macro base station, the present invention provides a notification method for a user terminal to receive modification notification information for notifying modification in system information from the micro base station, the notification method including: the macro base station notifying the micro base station of a subframe pattern including a protection subframe to protect the modification notification information every a plurality of radio frames; and the micro base station notifying the user terminal of identification information of the protection subframe in the subframe pattern.
    Type: Grant
    Filed: November 8, 2011
    Date of Patent: August 11, 2015
    Assignee: NTT DOCOMO, INC.
    Inventors: Tetsushi Abe, Mikio Iwamura, Hideaki Takahashi, Hiroyuki Ishii, Satoshi Nagata, Naoto Ookubo, Nobuhiko Miki, Anil Umesh
  • Patent number: 9066313
    Abstract: A base station includes a connection processing unit that performs connection processes between user terminals registered in a user terminal registration unit and the base station, and between user terminals other than the user terminals registered in the user terminal registration unit and the base station; a resource amount measurement unit that measures an amount of resources utilized by the base station; and a call disconnection user terminal selecting unit that selects, when the resource amount measurement unit measures that the amount of the resources is greater than or equal to a predetermined threshold value, the user terminal for which a call is to be disconnected, among the user terminals other than the user terminals registered in the user terminal registration unit. The connection processing unit disconnects a connection with the user terminal for which the call is to be disconnected.
    Type: Grant
    Filed: December 21, 2011
    Date of Patent: June 23, 2015
    Assignee: NTT DOCOMO, INC.
    Inventors: Kosuke Fujino, Kazunori Obata, Seigo Harano, Tadashi Uchiyama, Hiroyuki Ishii, Naoto Ookubo
  • Patent number: 9055480
    Abstract: A mobile communication method according to the present invention includes a step A of notifying, by a radio base station eNB, a mobile station UE during communication in a subordinate cell #1 of “CSI-RS/Muting configuration information” indicating a transmission method of CSI-RS; and a step B of performing, by the mobile station UE, a reception process on the basis of the “CSI-RS/Muting configuration information”.
    Type: Grant
    Filed: November 18, 2011
    Date of Patent: June 9, 2015
    Assignee: NTT DOCOMO, INC.
    Inventors: Satoshi Nagata, Tetsushi Abe, Naoto Ookubo, Mikio Iwamura
  • Patent number: 8995349
    Abstract: The present invention is designated to reduce the deterioration of transmission characteristics upon data transmission, even when soft buffer memory for retransmission control is not sufficiently secured in a mobile terminal apparatus. The present invention provides the steps of, in a base station apparatus (eNB), performing channel coding of information bits (ST 802), performing a rate matching process for the coded bits after interleaving (ST 804), and transmitting transmission data to match the coded bit length after rate matching, to a mobile terminal apparatus (UE) (ST 806), and, in the mobile terminal apparatus (UE), receiving the transmission data (ST 807), performing channel decoding of the received data (ST 810), and discarding part of the received data in accordance with the size of the soft buffer memory in the mobile terminal apparatus (UE) and storing this in the soft buffer memory (ST 812 and ST 813).
    Type: Grant
    Filed: January 5, 2012
    Date of Patent: March 31, 2015
    Assignee: NTT DOCOMO, INC.
    Inventors: Tetsushi Abe, Kazuaki Takeda, Naoto Ookubo, Hiroyuki Ishii, Yuta Sagae
  • Publication number: 20150004976
    Abstract: An eNB 110 includes an HO activation metric acquisition unit 111 which acquires a metric indicating a state of a voice call to be processed through the eNB 110, a mobile station state acquisition unit 112 which acquires a state of a mobile station processing the voice call, and an HO processing unit 113 which transmits a handover instruction, instructing a handover of the mobile station to a 3G system, to the mobile station when a value of the metric acquired by the HO activation metric acquisition unit 111 exceeds a predetermined threshold and when the state of the mobile station acquired by the mobile station state acquisition unit 112 satisfies a predetermined condition.
    Type: Application
    Filed: September 6, 2012
    Publication date: January 1, 2015
    Applicant: NTT DOCOMO, INC.
    Inventor: Naoto Ookubo
  • Publication number: 20140328239
    Abstract: A radio base station apparatus includes an information retrieval unit configured to retrieve information of the radio base station apparatus or information of a device that is connected to the radio base station apparatus, a timer value determination unit configured to determine, based on the retrieved information, a timer value representing a time period from termination of data communication with a mobile station until causing the mobile station to transition to an idle state; and an idle transition controller configured to cause the mobile station to transition to the idle state, based on the determined timer value.
    Type: Application
    Filed: November 12, 2012
    Publication date: November 6, 2014
    Applicant: NTT DOCOMO, INC.
    Inventors: Takahiro Takiguchi, Kohei Kiyoshima, Naoto Ookubo, Kenichiro Aoyagi, Anil Umesh, Tooru Uchino
  • Publication number: 20140226603
    Abstract: A base station 100 includes a scheduling processing unit 109 configured to schedule multiple mobile stations to the PDCCH, and a UE-type judgment unit 107 configured to judge whether each of the mobile stations is an OLD UE supporting only CFI=1 to 3 or a NEW UE supporting CFI=1 to 4. For a first subframe, the scheduling processing unit 109 schedules the OLD UE to the PDCCH by use of any one of CFI=1 to 3. For a second subframe different from the first subframe, the scheduling processing unit 109 schedules the NEW UE to the PDCCH by use of any one of CFI=1 to 4.
    Type: Application
    Filed: September 6, 2012
    Publication date: August 14, 2014
    Applicant: NTT DOCOMO, INC.
    Inventors: Naoto Ookubo, Yoshiaki Ofuji
  • Publication number: 20140226604
    Abstract: A base station 100 includes a scheduling processing unit 109 configured to schedule each of multiple mobile stations to the PDCCH, and a UE-type judgment unit 107 configured to judge whether each of the mobile stations is an OLD UE supporting only CFI=1 to 3 or a NEW UE supporting CFI=1 to 4. The scheduling processing unit 109 schedules each of the multiple UEs to the PDCCH by use of any one of CFI=1 to 3 when UEs targeted to be scheduled to the PDCCH include an OLD UE.
    Type: Application
    Filed: September 6, 2012
    Publication date: August 14, 2014
    Applicant: NTT DOCOMO, INC.
    Inventors: Naoto Ookubo, Yoshiaki Ofuji
  • Publication number: 20140220989
    Abstract: A base station 100 includes: an external interface 101 configured to acquire the number of transmissions of the system information to the mobile station; a table holding unit 107 configured to hold a table in which a payload size of the system information, the number of transmissions, and the number of radio resource blocks corresponding to a combination of the payload size and the number of transmissions are associated with one another; a system information transmission control unit 105 configured to determine radio resource blocks required for the transmission of the system information, on the basis of the table held in the table holding unit 107; and a transmission data generation unit 111 configured to map the system information to predetermined regions of the shared channel by using the radio resource blocks determined by the system information transmission control unit 105.
    Type: Application
    Filed: August 3, 2012
    Publication date: August 7, 2014
    Applicant: NTT DOCOMO, INC.
    Inventors: Yoshiaki Ofuji, Naoto Ookubo
  • Publication number: 20140219180
    Abstract: A base station 100 maps the system information formed of multiple blocks (SIB) to predetermined regions of a downlink shared channel and transmits the mapped system information to the mobile station. The base station 100 includes: a system information transmission control unit 105 configured to divide each of the predetermined regions into a first half and a second half in a time direction; and a transmission data generation unit 111 configured to map the system information to at least one of the first half and the second half. The system information transmission control unit 105 switches positions of the first half and the second half in rotation every transmission timing of the predetermined regions on the shared channel.
    Type: Application
    Filed: August 3, 2012
    Publication date: August 7, 2014
    Applicant: NTT DOCOMO, INC.
    Inventors: Yoshiaki Ofuji, Naoto Ookubo
  • Publication number: 20140204741
    Abstract: A base station 100 includes: a parameter control unit 103 configured to select either a normal control parameter used during normal time or an emergency control parameter used during an emergency where the number of voice calls to be handled increases from the number during normal time; and a scheduling unit 105 configured to schedule a PDSCH for a mobile station 200A based on either the normal control parameter or the emergency control parameter selected by the parameter control unit 103. The normal and emergency control parameters allow the number of voice calls processable by the base station 100 to change, and the emergency control parameter increases the number of processable voice calls to a number larger than that of the normal control parameter.
    Type: Application
    Filed: August 21, 2012
    Publication date: July 24, 2014
    Applicant: NTT DOCOMO, INC.
    Inventors: Naoto Ookubo, Yoshiaki Ofuji, Sadayuki Abeta
  • Publication number: 20130343270
    Abstract: In order to assure reception of broadcast information by a user terminal handed over to a micro base station by CRE (Cell Range Expansion) and to reduce the number of transmission stopped subframes in a macro base station, the present invention provides a notification method for a user terminal to receive modification notification information for notifying modification in system information from the micro base station, the notification method including: the macro base station notifying the micro base station of a subframe pattern including a protection subframe to protect the modification notification information every a plurality of radio frames; and the micro base station notifying the user terminal of identification information of the protection subframe in the subframe pattern.
    Type: Application
    Filed: November 8, 2011
    Publication date: December 26, 2013
    Applicant: NTT DOCOMO, INC.
    Inventors: Tetsushi Abe, Mikio Iwamura, Hideaki Takahashi, Hiroyuki Ishii, Satoshi Nagata, Naoto Ookubo, Nobuhiko Miki, Anil Umesh
  • Publication number: 20130315182
    Abstract: A base station of a mobile communication system includes a scheduler that generates uplink grant information indicating that uplink radio resources are allocated to less than or equal to a first multiplexing number of units of user equipment, a transmitter that transmits a control signal including the uplink grant information to the user equipment, and a receiver that receives an uplink signal which is transmitted by the user equipment. When a second multiplexing number being less than the first multiplexing number or more units of the user equipment exist which transmit periodically generated periodic data, and when the user equipment exists which transmits non-periodic data generated at non-periodic timing, the scheduler generates the uplink grant information indicating that the uplink radio resources are allocated to the second multiplexing number of the units of the user equipment that transmit periodic data and to the user equipment that transmits non-periodic data.
    Type: Application
    Filed: April 4, 2012
    Publication date: November 28, 2013
    Applicant: NTT DOCOMO, INC.
    Inventors: Rika Kitou, Kohei Kiyoshima, Naoto Ookubo, Hiroyuki Ishii, Yoshiaki Ofuji, Mikio Iwamura, Anil Umesh
  • Publication number: 20130308607
    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: Application
    Filed: November 8, 2011
    Publication date: November 21, 2013
    Applicant: NTT DOCOMO, INC.
    Inventors: Tetsushi Abe, Satoshi Nagata, Nobuhiko Miki, Naoto Ookubo
  • Publication number: 20130308592
    Abstract: A base station in a mobile communication system includes: a quality information obtaining unit configured to obtain quality information indicating a radio channel state of a user apparatus; an assignment period selection unit configured to select an assignment period corresponding to the quality information of the user apparatus from a predetermined correspondence relationship between each of a plurality of choices of assignment periods for assigning radio resources to periodic data that occurs periodically and a value of quality information indicating a radio channel state; a scheduling unit configured to determine radio resources to be assigned to the user apparatus in the assignment period that is selected; and a radio communication unit configured to communicate, by radio, user data including periodic data of the user apparatus by using the radio resources determined by the scheduling unit.
    Type: Application
    Filed: April 24, 2012
    Publication date: November 21, 2013
    Applicant: NTT DOCOMO, INC.
    Inventors: Rika Kitou, Kohei Kiyoshima, Naoto Ookubo, Hiroyuki Ishii, Yoshiaki Ofuji, Mikio Iwamura, Anil Umesh
  • Publication number: 20130308540
    Abstract: The present invention is designated to reduce the deterioration of transmission characteristics upon data transmission, even when soft buffer memory for retransmission control is not sufficiently secured in a mobile terminal apparatus. The present invention provides the steps of, in a base station apparatus (eNB), performing channel coding of information bits (ST 802), performing a rate matching process for the coded bits after interleaving (ST 804), and transmitting transmission data to match the coded bit length after rate matching, to a mobile terminal apparatus (UE) (ST 806), and, in the mobile terminal apparatus (UE), receiving the transmission data (ST 807), performing channel decoding of the received data (ST 810), and discarding part of the received data in accordance with the size of the soft buffer memory in the mobile terminal apparatus (UE) and storing this in the soft buffer memory (ST 812 and ST 813).
    Type: Application
    Filed: January 5, 2012
    Publication date: November 21, 2013
    Applicant: NTT DOCOMO, INC.
    Inventors: Tetsushi Abe, Kazuaki Takeda, Naoto Ookubo, Hiroyuki Ishii, Yuta Sagae
  • Publication number: 20130301602
    Abstract: A base station in a mobile communication system includes a scheduling unit generating downlink grant information indicating that downlink radio resources should be allocated to not more than a first multiplex number of user devices; and a transmission unit transmitting control signals containing the downlink grant information and data signals mapped to the radio resources specified by the downlink grant information, wherein, when less than the first multiplex number and not less than a second multiplex number being less than the first multiplex number, of user devices that receive periodically generated periodic data as data signals exist, and user devices that receive non-periodically generated non-periodic data as data signals exist, the scheduling unit generates downlink grant information indicating that the downlink radio resources should be allocated to the second multiplex number of user devices receiving the periodic data and the user devices receiving the non-periodic data.
    Type: Application
    Filed: April 6, 2012
    Publication date: November 14, 2013
    Applicant: NTT DOCOMO, INC.
    Inventors: Tooru Uchino, Mikio Iwamura, Yoshiaki Ofuji, Hiroyuki Ishii, Anil Umesh, Naoto Ookubo, Kohei Kiyoshima
  • Publication number: 20130286995
    Abstract: A base station of a communication system includes a quality information retrieval unit that retrieves quality information indicating a radio channel state of user equipment, a threshold value determination unit that determines, for each of the user equipment, a threshold value for at least one of a data retention amount and a data retention time period, depending on the quality information, a scheduler that calculates a scheduling coefficient for the user equipment for which at least the one of the data retention amount and the data retention time period exceeds the threshold value, and that allocates a radio resource to the user equipment at least in accordance with a magnitude of the scheduling coefficient, and a notification unit that reports to the user equipment that the radio resource is allocated.
    Type: Application
    Filed: March 12, 2012
    Publication date: October 31, 2013
    Applicant: NTT DOCOMO, INC.
    Inventors: Tooru Uchino, Mikio Iwamura, Yoshiaki Ofuji, Hiroyuki Ishii, Anil Umesh, Naoto Ookubo, Kohei Kiyoshima