Patents by Inventor Yousuke Iizuka

Yousuke Iizuka 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: 20090023392
    Abstract: An increase in the power consumption and deterioration of the reception characteristic which can arise as a result of installing a multi-path interference removing apparatus are suppressed. The multi-path interference removing apparatus is operated only in the following cases: a case where a mobile communication terminal is in a communication active state, a case where communication takes place via a base station to which the adaptive modulation and coding technology is applied, a case where the number of reception paths of the mobile communication terminal is two or more paths, a case where the speed of motion of the mobile communication terminal is 60 km/h or less, and a case where the Signal to Interference power Ratio is 8 dB or more.
    Type: Application
    Filed: January 23, 2006
    Publication date: January 22, 2009
    Applicant: NTT DoCoMo, Inc.
    Inventors: Yousuke Iizuka, Shinsuke Ogawa, Takeshi Nakamori
  • Publication number: 20080318614
    Abstract: To provide a mobile station and a transmission power control method in the mobile station, which are capable of improving the power saving characteristic associated with the transmission power control in the mobile station under a condition in which the transmit diversity is applied. The transmission power of feedback information (11: FBI) is controlled on the basis of control information (TPC) transmitted through a sub-information downlink channel (21) from a base station (210) as a main branch, only when it is determined by a communication method determining section 103 that a cosed loop transmit diversity can be applied (step S201: Yes), and when it is determined by a communication base station determining section 104 that sub-information downlink channels (21, 22) and sub-information uplink channels (11, 12) are connected to a plurality of base stations (step S202: Yes).
    Type: Application
    Filed: June 20, 2008
    Publication date: December 25, 2008
    Applicant: NTT DoCoMo, Inc.
    Inventors: Yousuke IIZUKA, Yukihiko OKUMURA
  • Publication number: 20080311910
    Abstract: A mobile station includes a handover controller. When the mobile station simultaneously communicates with a plurality of radio base stations by using first channels and communicates only with a certain one of the plurality of radio base stations by using a second communication channel, and even when the radio quality of the certain radio base station communicating by using the second communication channel becomes deteriorated, the handover controller maintains communications with the certain radio base station communicating by using the second communication channel.
    Type: Application
    Filed: July 20, 2007
    Publication date: December 18, 2008
    Applicant: NTT DocoMo, Inc.
    Inventors: Hiroyuki Ishii, Yousuke Iizuka
  • Publication number: 20080253310
    Abstract: Properties of a mobile communication terminal car be improved by eliminating interference according to environments of various reception paths. The mobile communication terminal generates a delay profile by a common pilot chapel sent from a base station and measures received electric power and delay amount of the reception path. Next, based on the delay profile, the delay amount of a reception path P4 farthest from a reference path P1 is set as a maximum delay amount D. However the farthest reception path P4 is excluded from the subjects of interference elimination when the electric power of which differs by a amount not less than 10 dB with respect to the electric power of the reference path P1, and the delay amount of a reception path P3 next farthest from the reference path P1 is set as the maximum delay amount D. After that, a chapel matrix s generated based on the number of samples and the maximum delay amount D.
    Type: Application
    Filed: January 17, 2006
    Publication date: October 16, 2008
    Applicant: NTT DOCOMO, INC.
    Inventors: Yousuke Iizuka, Takeshi Nakamori, Shinsuke Ogawa
  • Publication number: 20080096510
    Abstract: When the diversity reception is cut, communications with the base station are continued. When it is judged by the judgment section of the mobile communication terminal that a predetermined disconnection requirement for disconnecting diversity reception is satisfied, the gain control section of the digital baseband circuitry 20 reduces the gain of the AGC14B contained in the RF receiver circuitry 10B constituting the disconnection target by a fixed value at fixed times. Diversity reception is cut after the level of the signal output by the AGC14B has reached zero.
    Type: Application
    Filed: January 17, 2006
    Publication date: April 24, 2008
    Applicant: NTT DoCoMo, Inc.
    Inventors: Yousuke Iizuka, Shinsuke Ogawa, Masahiro Sakai
  • Publication number: 20070036205
    Abstract: There is disclosed a mobile communication terminal equipped with a multipath interference canceller for canceling multipath interference, comprising number-of-samples controlling unit for controlling a number of samples to be sampled from a received signal, channel matrix generating unit for generating a channel matrix on the basis of sample data of samples as many as the number controlled by the number-of-samples controlling means and, interference canceling emit for canceling multipath interference on the basis of the channel matrix generated by the channel matrix generating unit.
    Type: Application
    Filed: August 7, 2006
    Publication date: February 15, 2007
    Applicant: NTT DoCoMo, Inc.
    Inventors: Takeshi Nakamori, Hiroyuki Ishii, Yousuke Iizuka
  • Publication number: 20060218457
    Abstract: The packet reception section of the cellular phone receives a packet transmitted from the base station and the transmission error detection section detects a transmission error of the received packet. When the transmission error is detected, the retransmission request transmission section transmits a retransmission request to request the retransmission of the packet in which the transmission error is detected, to the base station, and the sample timing control section shifts the sample timing of the A/D converter by a half clock.
    Type: Application
    Filed: March 9, 2006
    Publication date: September 28, 2006
    Applicant: NTT DoCoMo, Inc.
    Inventors: Takeshi Nakamori, Shinsuke Ogawa, Yousuke Iizuka
  • Publication number: 20060203854
    Abstract: Improve efficiency of sampling of an A/D converter while suppressing power consumption. A packet receiving section receives six packets included in one frame transmitted from a base station, a sample timing control section shifts sample timing of the A/D converter by a half clock between former three packets and latter three packets out of six packets included in one frame.
    Type: Application
    Filed: March 10, 2006
    Publication date: September 14, 2006
    Applicant: NTT DoCoMo, Inc.
    Inventors: Takeshi Nakamori, Shinsuke Ogawa, Yousuke Iizuka
  • Publication number: 20050190737
    Abstract: A mobile station and a base station are disclosed. The mobile station, when transmitting a reservation request signal and a data packet, controls radio parameters of reservation request signal transmission and data packet transmission so that communication quality required by the data packet transmission is satisfied, and system capacity is maximized. Further, the mobile station transmits the reservation request signal and data packet, the radio parameters of which are controlled, to the base station.
    Type: Application
    Filed: February 7, 2005
    Publication date: September 1, 2005
    Applicant: NTT DoCoMo, Inc.
    Inventors: Motohiro Tanno, Yousuke Iizuka, Mamoru Sawahashi