Patents by Inventor Toshiyuki Futakata

Toshiyuki Futakata 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: 8488585
    Abstract: There is provided a mobile station that minimizes a pause or a silent period during communication at the time of a reconnection process of communication, thereby to improve the user's convenience and achieve the reduction in the load applied onto the communication network or the mobile station. When an out of synchronization detection unit 4 of a mobile station 2 detects out of synchronization, an individual timer value determination unit 53 selects two or more timer value change triggers from timer value change triggers stored in a timer value change trigger memory 51, and then determines the timer values respectively for the timer value change triggers that have been selected, based upon the determination rules stored in an individual timer value determination rule memory 52. A reconnection timer value calculation unit 54 calculates an appropriate reconnection timer value based upon the two or more individual timer values that have been determined by the individual timer value determination unit 53.
    Type: Grant
    Filed: May 7, 2009
    Date of Patent: July 16, 2013
    Assignee: NTT DoCoMo, Inc.
    Inventors: Seiko Shimizu, Masayuki Furusawa, Taro Ishikawa, Toshiyuki Futakata
  • Publication number: 20110065437
    Abstract: There is provided a mobile station that minimizes a pause or a silent period during communication at the time of a reconnection process of communication, thereby to improve the user's convenience and achieve the reduction in the load applied onto the communication network or the mobile station. When an out of synchronization detection unit 4 of a mobile station 2 detects out of synchronization, an individual timer value determination unit 53 selects two or more timer value change triggers from timer value change triggers stored in a timer value change trigger memory 51, and then determines the timer values respectively for the timer value change triggers that have been selected, based upon the determination rules stored in an individual timer value determination rule memory 52. A reconnection timer value calculation unit 54 calculates an appropriate reconnection timer value based upon the two or more individual timer values that have been determined by the individual timer value determination unit 53.
    Type: Application
    Filed: May 7, 2009
    Publication date: March 17, 2011
    Applicant: NTT Docomo, Inc.
    Inventors: Seiko Shimizu, Masayuki Furusawa, Taro Ishikawa, Toshiyuki Futakata
  • Patent number: 7720478
    Abstract: There is provided a control device enabling switching of communication of a mobile terminal with one system to communication with another system while reducing power consumption and workload of the mobile terminal. The control device is used in a communication system including a first mobile communication system, a second mobile communication system, and a mobile terminal being in communication with the first mobile communication system. The control device comprises a position measuring unit for measuring the position of the mobile terminal, a judgment unit for making a determination whether or not to switch the communication of the mobile terminal from the first mobile communication system to the second mobile communication system according to a position measurement result of the position measuring unit, and a switching unit for performing the above switching operation according to the determination of the judgment unit.
    Type: Grant
    Filed: March 25, 2003
    Date of Patent: May 18, 2010
    Assignee: NTT DoCoMo, Inc.
    Inventors: Takayuki Ishiguro, Mayu Yamada, Sung Uk Moon, Hiroyuki Ishii, Toshiyuki Futakata, Tomohiro Dohi
  • Patent number: 7599446
    Abstract: A modulation device comprises a modulation unit (2) that modulates data in a hierarchical manner using multiple types of modulation techniques, and a transmission unit (3) that transmits the hierarchically modulated data. A demodulation device comprises a receiving unit (4) that receives the hierarchical modulation data having been subjected to hierarchical modulation using multiple types of modulation techniques, and a demodulation unit (6) that demodulates the hierarchical modulation data using a demodulation technique corresponding to a specific hierarchy of the hierarchical modulation data.
    Type: Grant
    Filed: September 15, 2003
    Date of Patent: October 6, 2009
    Assignee: NTT DoCoMo, Inc.
    Inventors: Sung Uk Moon, Takahiro Hayashi, Toshiyuki Futakata
  • Patent number: 7519102
    Abstract: The present invention relates to a spreading signal assigning method and a signal transmitting method in a direct sequence CDMA mobile communication system, a mobile wireless communication system using the methods, and a transmitter, a receiver and a transceiver in the mobile wireless communication system in which an assignment method of a second spreading code is devised such that various services can be provided. The invention is configured such that a signal spread with the second spreading code is transmitted between a base station and a mobile station by assigning a code associated with each base station group or a code associated with each network type to which the base station group belongs as the second spreading code.
    Type: Grant
    Filed: May 7, 1999
    Date of Patent: April 14, 2009
    Assignee: NTT Mobile Communications Network, Inc.
    Inventors: Toshiyuki Futakata, Masatoshi Kimoto, Tsutomu Taguchi, Yoshiaki Hiramatsu
  • Patent number: 7502359
    Abstract: The present invention provides a radio base station for preventing degradation of transmission quality characteristics even when there are time differences between the instant of channel estimation of uplink time slots UL#1 to UL#N and the instant of transmission of transmission data via downlink time slots DL#1 to DL#N. The radio base station includes transmit diversity controllers 141 to 14N for controlling transmit diversity to be used for downlink time slots DL#1 to DL#N and a data transmitter 15 for transmitting data via downlink time slots DL#1 to DL#N using the controlled transmit diversity.
    Type: Grant
    Filed: September 6, 2002
    Date of Patent: March 10, 2009
    Assignee: NTT DoCoMo, Inc.
    Inventors: Sung Uk Moon, Toshiyuki Futakata
  • Patent number: 7342943
    Abstract: The present invention provides a radio base station using the conventional downlink transmit diversity which can compensate for the degradation of transmission quality even when a plurality of users (mobile terminals) share a single time slot using a code division multiple system. The radio base station includes a channel estimator 16 for performing channel estimation of an uplink time slot; a transmit diversity controller 141 to 14N for controlling the transmit diversity used for downlink time slots DL#1 to DL#N based on said channel estimation and the number of users sharing the downlink time slot when using a code division multiple system; a data transmitter 15 for transmitting data via downlink time slots DL#1 to DL#N using the controlled transmit diversity.
    Type: Grant
    Filed: October 24, 2002
    Date of Patent: March 11, 2008
    Assignee: NTT DoCoMo, Inc.
    Inventors: Sung Uk Moon, Toshiyuki Futakata
  • Patent number: 7313400
    Abstract: There is provided a radio communication device able to adaptively adjust a pilot symbol insertion rate and improve efficiency of channel estimation and data transmission. It comprises a channel estimation unit that performs the channel estimation using the pilot symbols, a storage unit that stores a plurality of estimated values obtained by the channel estimation unit, a determination unit that compares the estimated values stored in the storage unit and determines an amount of change of the estimated values, and a notification unit that notifies the pilot symbol insertion unit of the amount of change of the estimated values.
    Type: Grant
    Filed: May 5, 2003
    Date of Patent: December 25, 2007
    Assignee: NTT DoCoMo, Inc.
    Inventors: Sung Uk Moon, Toshiyuki Futakata, Tomohiro Dohi
  • Patent number: 7224676
    Abstract: A mobile station receives a signal based on a TDD method by receiving a signal based on a FDD method to acquire information of the signal based on the TDD method in a mobile communication system. For instance, the mobile station receives a signal based on a CDMA-FDD method. Then, the mobile station acquires information (e.g. information relating to a code, a frequency and a timing) of a signal based on a CDMA-TDD method from the signal based on the CDMA-FDD method. Then, the mobile station receives the signal based on the CDMA-TDD method on the basis of the acquired information.
    Type: Grant
    Filed: November 16, 2001
    Date of Patent: May 29, 2007
    Assignee: NTT DoCoMo Inc.
    Inventors: Shinji Uebayashi, Takanori Utano, Toshiyuki Futakata
  • Patent number: 7184448
    Abstract: The adaptive modulation method for use in a mobile communication system employing a TDMA scheme associates a modulation scheme with each time slot within a frame, and modulates transmission data of a communication channel using the modulation scheme associated with the time slot into which the communication channel is assigned.
    Type: Grant
    Filed: March 25, 2002
    Date of Patent: February 27, 2007
    Assignee: NTT DoCoMo, Inc.
    Inventors: Sung Uk Moon, Toshiyuki Futakata
  • Patent number: 7116647
    Abstract: A channel assigning method and a communication apparatus for executing appropriate channel assignment in a mobile communication system when both a channel for a service area based on a FDD method and a channel for a service area based on a TDD method can be assigned are provided. For example, if both a channel for a service area based on a CDMA-FDD method and channels for service areas based on a CDMA-TDD method can be assigned to a request for channel assignment, and a handover frequency of the mobile station related to the request is high, the channel for the service area based on the CDMA-FDD method is assigned.
    Type: Grant
    Filed: June 22, 2001
    Date of Patent: October 3, 2006
    Assignee: NTT DoCoMo, Inc.
    Inventors: Shinji Uebayashi, Toshiyuki Futakata
  • Patent number: 7092434
    Abstract: When a mobile station communicates with a base station by way of one or a plurality of other mobile stations, the mobile station acting as a relay station determines whether the data demodulated after being received is reception data for the mobile station or transfer data to be transmitted to the other mobile station or the base station, decides a modulation mode suitable for transmitting sum data of the transfer data and transmission data if the transmission data is generated in the mobile station, and transmits the sum data while modulating the sum data according to the modulation mode decided. The base station demodulates a reception signal relayed by the mobile stations according to the modulation mode of the mobile station having directly communicated with the base station, and identifies each user data multiplexed.
    Type: Grant
    Filed: June 25, 2002
    Date of Patent: August 15, 2006
    Assignee: NTT DoCoMo, Inc.
    Inventors: Sung Uk Moon, Toshiyuki Futakata
  • Patent number: 7035660
    Abstract: In a mobile communication system, interference power from adjacent cells is effectively reduced and transmission power is limited. A transmission loss estimation unit 202 and a transmission power estimation unit 204 estimate transmission power necessary for transmission of a downstream signal. According to an upstream signal from each of plurality of mobile terminal devices to a base station, a grouping unit 206 divides a plurality of mobile terminal devices into groups sharing a plurality of wireless resources according to the estimated transmission powers. Downstream signals to be transmitted to mobile terminal devices belonging to each of the groups formed by the grouping means are transmitted simultaneously with each other. Also, priorities are set for the plurality of wireless resources and the mobile terminal devices belonging to the groups divided by the grouping unit 206 are assigned according to the set priorities.
    Type: Grant
    Filed: July 24, 2002
    Date of Patent: April 25, 2006
    Assignee: NTT DoCoMo, Inc.
    Inventors: Toshiyuki Futakata, Sung Uk Moon
  • Patent number: 7035590
    Abstract: A mobile phone 1 receives a home cell signal sent from a base station B1 and a foreign cell signal sent from a base station B2 or from a mobile phone 21 in a foreign cell A2. The mobile phone 1 receives spreading codes C2–C4 sent from the base station B1, as home cell codes. The mobile phone 1 detects the interference between the home cell signal and the foreign cell signal. When the interference is detected, the mobile phone 1 receives a spreading code C1 sent from the base station B2 or from the mobile phone 21, as a foreign cell code. The mobile phone 1 cancels an interference signal by joint detection, using the home cell codes and the foreign cell code.
    Type: Grant
    Filed: December 6, 2002
    Date of Patent: April 25, 2006
    Assignee: NTT DoCoMo, Inc.
    Inventors: Takayuki Ishiguro, Toshiyuki Futakata, Makoto Ito, Sung Uk Moon
  • Publication number: 20040203786
    Abstract: There is provided a control device enabling switching of communication of a mobile terminal with one system to communication with another system while reducing power consumption and workload of the mobile terminal. The control device is used in a communication system including a first mobile communication system, a second mobile communication system, and a mobile terminal being in communication with the first mobile communication system. The control device comprises a position measuring unit for measuring the position of the mobile terminal, a judgment unit for making a determination whether or not to switch the communication of the mobile terminal from the first mobile communication system to the second mobile communication system according to a position measurement result of the position measuring unit, and a switching unit for performing the above switching operation according to the determination of the judgment unit.
    Type: Application
    Filed: March 25, 2003
    Publication date: October 14, 2004
    Applicant: NTT DoCoMo, Inc.
    Inventors: Takayuki Ishiguro, Mayu Yamada, Sung Uk Moon, Hiroyuki Ishii, Toshiyuki Futakata, Tomohiro Dohi
  • Publication number: 20040066844
    Abstract: A modulation device comprises a modulation unit (2) that modulates data in a hierarchical manner using multiple types of modulation techniques, and a transmission unit (3) that transmits the hierarchically modulated data. A demodulation device comprises a receiving unit (4) that receives the hierarchical modulation data having been subjected to hierarchical modulation using multiple types of modulation techniques, and a demodulation unit (6) that demodulates the hierarchical modulation data using a demodulation technique corresponding to a specific hierarchy of the hierarchical modulation data.
    Type: Application
    Filed: September 15, 2003
    Publication date: April 8, 2004
    Applicant: NTT DoCoMo, Inc
    Inventors: Sung Uk Moon, Takahiro Hayashi, Toshiyuki Futakata
  • Publication number: 20030218993
    Abstract: A base station 1 according to the present invention is provided with a transmission power manager 2, a channel determiner 4, and a transmission power calculator 5. The transmission power manager 2 determines whether a total transmission power in a time slot N exceeds a maximum transmission power. When the transmission power manager 2 determines that the total transmission power in the time slot N exceeds the maximum transmission power, the channel determiner 4 determines whether there is a channel in which a transmission power can be decreased in the time slot N. When the channel determiner 4 determines that there is such a channel, the transmission power calculator 5 calculates a transmission power to be decreased in the time slot N in the channel.
    Type: Application
    Filed: May 20, 2003
    Publication date: November 27, 2003
    Applicant: NTT DoCoMo, Inc.
    Inventors: Sung Uk Moon, Masafumi Usuda, Toshiyuki Futakata, Tomohiro Dohi
  • Publication number: 20030211851
    Abstract: There is provided a radio communication device able to adaptively adjust a pilot symbol insertion rate and improve efficiency of channel estimation and data transmission. It comprises a channel estimation unit that performs the channel estimation using the pilot symbols, a storage unit that stores a plurality of estimated values obtained by the channel estimation unit, a determination unit that compares the estimated values stored in the storage unit and determines an amount of change of the estimated values, and a notification unit that notifies the pilot symbol insertion unit of the amount of change of the estimated values.
    Type: Application
    Filed: May 5, 2003
    Publication date: November 13, 2003
    Applicant: NTT DoCoMo, Inc.
    Inventors: Sung Uk Moon, Toshiyuki Futakata, Tomohiro Dohi
  • Publication number: 20030128679
    Abstract: A mobile phone 1 receives a home cell signal sent from a base station B1 and a foreign cell signal sent from a base station B2 or from a mobile phone 21 in a foreign cell A2. The mobile phone 1 receives spreading codes C2-C4 sent from the base station B1, as home cell codes. The mobile phone 1 detects the interference between the home cell signal and the foreign cell signal. When the interference is detected, the mobile phone 1 receives a spreading code C1 sent from the base station B2 or from the mobile phone 21, as a foreign cell code. The mobile phone 1 cancels an interference signal by joint detection, using the home cell codes and the foreign cell code.
    Type: Application
    Filed: December 6, 2002
    Publication date: July 10, 2003
    Applicant: NTT DoCoMo, Inc.
    Inventors: Takayuki Ishiguro, Toshiyuki Futakata, Makoto Ito, Sung Uk Moon
  • Publication number: 20030081574
    Abstract: The present invention provides a radio base station using the conventional downlink transmit diversity which can compensate for the degradation of transmission quality even when a plurality of users (mobile terminals) share a single time slot using a code division multiple system. The radio base station includes a channel estimator 16 for performing channel estimation of an uplink time slot; a transmit diversity controller 141 to 14N for controlling the transmit diversity used for downlink time slots DL#1 to DL#N based on said channel estimation and the number of users sharing the downlink time slot when using a code division multiple system; a data transmitter 15 for transmitting data via downlink time slots DL#1 to DL#N using the controlled transmit diversity.
    Type: Application
    Filed: October 24, 2002
    Publication date: May 1, 2003
    Applicant: NTT DoCoMo, Inc.
    Inventors: Sung Uk Moon, Toshiyuki Futakata