Patents by Inventor Takayuki Ishiguro

Takayuki Ishiguro 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: 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
  • Patent number: 6961577
    Abstract: A communication channel allocation method allocates a communication channel to communications between a mobile terminal device and a second radio base station using a second frequency band which is close to a first frequency band used by a first radio base station, by detecting a first distance between the second radio base station and the first radio base station, detecting a second distance between the second radio base station and the mobile terminal device when the first distance is less than a first threshold, and allocating a communication channel of a frequency far from the first frequency band in the second frequency band to the communications between the second radio base station and the mobile terminal device when the second distance is less than a second threshold.
    Type: Grant
    Filed: May 24, 2002
    Date of Patent: November 1, 2005
    Assignee: NTT DoCoMo, Inc.
    Inventors: Rie Nagato, Shinji Uebayashi, Takayuki Ishiguro, Osamu Nakamura
  • Publication number: 20050148336
    Abstract: A communication channel allocation method allocates a communication channel to communications between a mobile terminal device and a second radio base station using a second frequency band which is close to a first frequency band used by a first radio base station, by detecting a first distance between the second radio base station and the first radio base station, detecting a second distance between the second radio base station and the mobile terminal device when the first distance is less than a first threshold, and allocating a communication channel of a frequency far from the first frequency band in the second frequency band to the communications between the second radio base station and the mobile terminal device when the second distance is less than a second threshold.
    Type: Application
    Filed: February 16, 2005
    Publication date: July 7, 2005
    Applicant: NTT DoCoMo, Inc
    Inventors: Rie Nagato, Shinji Uebayashi, Takayuki Ishiguro, Osamu Nakamura
  • Patent number: 6859647
    Abstract: A simplified interference elimination system is provided for eliminating from a first radio signal transmitted from a first radio terminal to a first radio base station, the effect of interference due to a second radio signal transmitted from a second radio terminal to a second radio base station. The second radio base station has an extractor for extracting the second radio signal from radio signals received in the second radio base station, and a transmitter for transmitting the extracted second radio signal to the first radio base station. The first radio base station has an interference eliminator for eliminating the second radio signal transmitted from the second radio base station from radio signals received in the first radio base station.
    Type: Grant
    Filed: May 23, 2002
    Date of Patent: February 22, 2005
    Assignee: NTT DoCoMo, Inc.
    Inventors: Takayuki Ishiguro, Osamu Nakamura, Shinji Uebayashi
  • 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: 20040196454
    Abstract: Defect in a edge portion of a disk is detected by irradiating a inspected region of an outer peripheral surface with light beam spot through an inside portion of the disk and receiving scattered light from the inspected region by means of a first light receiving system provided externally of the disk in a vicinity of the inspected region. Therefore, there is substantially no scattered light from alien attached externally of the disk.
    Type: Application
    Filed: April 2, 2004
    Publication date: October 7, 2004
    Inventor: Takayuki Ishiguro
  • Publication number: 20040038680
    Abstract: In radio communication, the throughput reduction of a whole radio communication system caused by discarding retransmission data at the time of handover is prevented. The system includes a radio terminal for conducting data transmission and reception with a radio base station by executing one or more processes, a process executer in the radio base station for executing processes depending upon a number of processes executed in the radio terminal, and transmitting/receiving data to/from the radio terminal, a handover monitor in the radio base station for monitoring for the occurrence of handover or for the possibility of occurrence of handover in the radio terminal, and a process number controller in the radio base station for controlling the number of processes executed by the process executer according to a result of monitoring conducted by the handover monitor.
    Type: Application
    Filed: August 20, 2003
    Publication date: February 26, 2004
    Applicant: NTT DoCoMo, Inc
    Inventors: Takayuki Ishiguro, Hiroyuki Ishii
  • Publication number: 20040018850
    Abstract: This invention provides a transmit power level deciding method that is carried out in a base station or in respective wireless terminals, those of which are constituents of a mobile communications system, for adequately controlling the transmit power level of uplink control signals to be sent from respective wireless terminals to the base station. For this purpose, respective wireless terminals measures a multiplex number of downlink control signals from the base station and decides the adequate transmit power level of the uplink control signal, which is containing NACK information, to be sent to the base station according to the measured multiplex number thereof, and respective wireless terminals controls the transmit power level of the uplink control signal.
    Type: Application
    Filed: July 22, 2003
    Publication date: January 29, 2004
    Applicant: NTT DoCoMo, Inc.
    Inventors: Takayuki Ishiguro, Hiroyuki Ishii
  • Publication number: 20040014477
    Abstract: A radio communication system comprises a radio terminal and a plurality of base stations. The base stations communicate with the radio terminal by connecting radio links with mutually different frequencies. The base stations comprise a control signal transmitter configured to transmit control signals in a plurality of control signal time slots included in one frame. The radio terminal comprises a reception time slot determining unit configured to determine reception time slots for receiving the control signals transmitted from the plurality of base stations, from among the plurality of control signal time slots, a control signal receiver configured to receive the control signals in the reception time slots determined by the reception time slot determining unit, and a communication signal transmitter configured to transmit communication signal to the base station in an uplink communication signal time slot other than the control signal time slots.
    Type: Application
    Filed: May 23, 2003
    Publication date: January 22, 2004
    Applicant: NTT DoCoMo, Inc.
    Inventors: Takayuki Ishiguro, Hiroyuki Ishii
  • Publication number: 20030236074
    Abstract: A receiver of a mobile station or a base station in radio communications is formed by a correlation unit for generating a delay profile for specifying paths by taking correlations by using replica signals for a received pilot signal, and a path selection unit for comparing a power level of each path in the delay profile with a threshold determined according to an index value regarding a communication state, selecting paths for which a comparison result satisfies a prescribed condition as valid paths, and outputting a selected delay profile formed by the valid paths as a channel estimation value.
    Type: Application
    Filed: June 20, 2003
    Publication date: December 25, 2003
    Applicant: NTT DoCoMo, Inc
    Inventors: Hiroyuki Ishii, Takayuki Ishiguro, Sung Uk Moon, Mayu Yamada
  • Publication number: 20030228870
    Abstract: A control device for carrying out control of first and second radio base stations at a time of handover from a first radio base station to a second radio base station in radio communications between a radio terminal and a radio base station is provided to prevent the use of signals other than the control signals currently used in the areas before and after the moving, in the same channel as the control signals currently used in the moving target area, during the handover, such that it is possible to improve the receiving quality of the control signals at the radio terminal.
    Type: Application
    Filed: June 4, 2003
    Publication date: December 11, 2003
    Applicant: NTT DoCoMo, Inc.
    Inventor: Takayuki Ishiguro
  • Publication number: 20030224829
    Abstract: At a time of the handover, the communications with respect to the radio terminal related to the handover are carried out by using the same antenna as the antenna with respect to the other radio terminal that is already located in the moving target area, so that interferences due to the difference in the propagation paths can be suppressed to the minimum, and the receiving quality can be improved.
    Type: Application
    Filed: June 2, 2003
    Publication date: December 4, 2003
    Applicant: NTT DoCoMo, Inc.
    Inventors: Takayuki Ishiguro, Hiroyuki Ishii
  • Patent number: 6617603
    Abstract: An image of a scanning position on a faceplate on a light receiving region defined by an arrangement of n light receiving elements such that an amount of light received by the light receiving region becomes a peak at a center of the light receiving region in an arranging direction of the light receiving elements and is gradually reduced substantially symmetrically toward both ends thereof in the same direction. Therefore, if there is no defect in the surface of the faceplate, levels of light receiving signals of the light receiving elements arranged substantially symmetrically in position on both sides of the light receiving region with respect to the center thereof as a reference are substantially equal and there is no substantial difference therebetween.
    Type: Grant
    Filed: March 1, 2002
    Date of Patent: September 9, 2003
    Assignee: Hitachi Electronics Engineering Co., Ltd.
    Inventors: Takayuki Ishiguro, Hiroshi Nakajima
  • 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: 20030072274
    Abstract: The mobile communication system for communications between a base station and a mobile station, employing a TDD method, sets up transmission power of the base station for each of downlink time slots that are to be transmitted next, based on receiving quality of downlink time slots that have been received by the mobile station immediately prior to transmitting the next time slots, and based on receiving power level of uplink time slots that are received by the base station.
    Type: Application
    Filed: October 16, 2002
    Publication date: April 17, 2003
    Applicant: NTT DoCoMo, Inc
    Inventors: Toshiyuki Futakata, Takayuki Ishiguro, Sung Uk Moon, Mayu Yamada
  • Patent number: 6509966
    Abstract: A defect detection optical system includes a light receiving system including n light receiving elements arranged in a direction perpendicular to a main scan direction, for focusing an image thereon such that the image becomes in the arranging direction of the light receiving elements, in which, when a width of the image focused thereon in the main scan direction is equal to or smaller than the width of the light receiving elements, light reflected from a recessed or protruded defect is swung in the width direction of the light receiving elements and a light receiving area of the light receiving elements is reduced. When the reflection light from the recessed or protruded defect is; swung in sloped portions of the defect, an amount of light received by the light receiving elements is at least reduced, so that two detection signals having levels lower than those when there is no defect are obtained.
    Type: Grant
    Filed: July 19, 2001
    Date of Patent: January 21, 2003
    Assignee: Hitachi Electronics Engineering Co., Ltd.
    Inventor: Takayuki Ishiguro
  • Publication number: 20020196804
    Abstract: A radio terminal (10) and a radio relay (20, 30, 40) perform radio communications therebetween by a radio communications system else than a TDMA system, ian interference measurer (13a) measures a degree of interference of each of radio slots constituting a radio channel employed in the radio communications system, a decision maker (13b, 13c) makes a decision, depending on a measurement result of the degree of interference, whether or not the radio communications by the radio communications system is able to be continued, and a switcher (42) switches, as the decision is made of the radio communications by the radio communications system to be unable to be continued, the radio communications system to a radio communications system of the TDMA system.
    Type: Application
    Filed: June 24, 2002
    Publication date: December 26, 2002
    Applicant: NTT DoCoMo, Inc.
    Inventors: Takayuki Ishiguro, Osamu Nakamura, Shinji Uebayashi
  • Publication number: 20020180959
    Abstract: A defect detecting optical system includes a light receiving optical system including an objective lens provided above the surface of the disk in parallel to the surface for receiving the scattered light and focusing an image of a test region of the disk on the light sensor through the objective lens and a plurality (n) of light illuminating systems provided around the objective lens equiangularly in a plane parallel to the disk with an angular interval of substantially 360°/n and emitting light beams to the test region with elevation angles in a range from 55° to 60° measured from the surface of the disk, where n is an integer equal to or larger than 3.
    Type: Application
    Filed: May 23, 2002
    Publication date: December 5, 2002
    Inventors: Hiroshi Nakajima, Takayuki Ishiguro
  • Publication number: 20020177444
    Abstract: A communication channel allocation method allocates a communication channel to communications between a mobile terminal device and a second radio base station using a second frequency band which is close to a first frequency band used by a first radio base station, by detecting a first distance between the second radio base station and the first radio base station, detecting a second distance between the second radio base station and the mobile terminal device when the first distance is less than a first threshold, and allocating a communication channel of a frequency far from the first frequency band in the second frequency band to the communications between the second radio base station and the mobile terminal device when the second distance is less than a second threshold.
    Type: Application
    Filed: May 24, 2002
    Publication date: November 28, 2002
    Applicant: NTT DoCoMo, Inc.
    Inventors: Rie Nagato, Shinji Uebayashi, Takayuki Ishiguro, Osamu Nakamura
  • Publication number: 20020177426
    Abstract: A simplified interference elimination system is provided for eliminating from a first radio signal transmitted from a first radio terminal to a first radio base station, the effect of interference due to a second radio signal transmitted from a second radio terminal to a second radio base station. The second radio base station has an extractor for extracting the second radio signal from radio signals received in the second radio base station, and a transmitter for transmitting the extracted second radio signal to the first radio base station. The first radio base station has an interference eliminator for eliminating the second radio signal transmitted from the second radio base station from radio signals received in the first radio base station.
    Type: Application
    Filed: May 23, 2002
    Publication date: November 28, 2002
    Applicant: NTT DoCoMo, Inc.
    Inventors: Takayuki Ishiguro, Osamu Nakamura, Shinji Uebayashi