Patents by Inventor Hidehiro Ando

Hidehiro Ando 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: 8737224
    Abstract: Disclosed is a communication method for switching between a first connection state, in which a data unit is transmitted in a first size, and a second connection state, in which a data unit is transmitted in a second size which is larger than the first size. The communication method comprises a step of maintaining the size of a data unit at the first size in a case where there is a transition from the first connection state to the second connection state after there had been a transition from the second connection state to the first connection state.
    Type: Grant
    Filed: July 2, 2010
    Date of Patent: May 27, 2014
    Assignee: NTT DoCoMo, Inc.
    Inventors: Takahiro Hayashi, Masafumi Masuda, Hidehiro Ando, Takaaki Sato, Yoshiyuki Yasuda
  • Patent number: 8615245
    Abstract: A radio network controller includes: a determination unit configured to determine a transmit diversity method to be used to transmit a signal from a base station to a mobile station, in accordance with a soft handover status of the mobile station; and an instruction/notification unit configured to instruct the transmit diversity method to the base station, in accordance with the determination result by the determination unit.
    Type: Grant
    Filed: December 13, 2005
    Date of Patent: December 24, 2013
    Assignee: NTT DoCoMo, Inc.
    Inventors: Masafumi Usuda, Takehiro Nakamura, Hidehiro Ando, Takuya Sato, Hiroyuki Ishii
  • Patent number: 8295332
    Abstract: In this invention, a channel estimation value of data symbols of a data channel is calculated by weighting and averaging pilot symbols in a parallel time multiplexing method. Also, a channel estimation value of data symbols during each data symbol interval is calculated by dividing data symbols in a slot into a plurality of data symbol intervals, selecting pilot symbols suitable for calculation of a channel estimation value of data symbols during each data symbol interval and weighting and averaging that pilot symbols. Also, a fading frequency is detected based on an inner product value of pilot symbols. Weighting factors are changed based on the detected fading frequency. Also, a channel estimation value is calculated by weighting and averaging pilot signals using a plurality of weighting sequences. The calculated channel estimation value is used to demodulate received data. The output data with the highest quality is selected by judging reliability of these plurality of demodulated data.
    Type: Grant
    Filed: February 23, 2011
    Date of Patent: October 23, 2012
    Assignee: NTT DoCoMo, Inc.
    Inventors: Yukihiko Okumura, Hidehiro Ando, Masafumi Usuda, Yoshihiro Ishikawa, Seizo Onoe
  • Publication number: 20120155392
    Abstract: Disclosed is a communication method for switching between a first connection state, in which a data unit is transmitted in a first size, and a second connection state, in which a data unit is transmitted in a second size which is larger than the first size. The communication method comprises a step of maintaining the size of a data unit at the first size in a case where there is a transition from the first connection state to the second connection state after there had been a transition from the second connection state to the first connection state.
    Type: Application
    Filed: July 2, 2010
    Publication date: June 21, 2012
    Applicant: NTT DOCOMO, INC.
    Inventors: Takahiro Hayashi, Masafumi Masuda, Hidehiro Ando, Takaaki Sato, Yoshiyuki Yasuda
  • Patent number: 8077794
    Abstract: A reception device for use in a mobile communication system having a mobile station and a radio base station to which transmission diversity for transmitting transmission signals using a plurality of antennas is applied in a downlink to the mobile station, is disclosed. The reception device includes a presumed probability control unit that sets a presumed probability for use in an antenna verification process of estimating a phase of the transmission signals from the plurality of antennas according to information about a channel of signals transmitted in an uplink from the mobile station to the radio base station when a closed loop transmission diversity control is performed by controlling the phase of the transmission signals from the plurality of antennas according to feedback information noticed by the mobile station to transmit the transmission signals.
    Type: Grant
    Filed: February 23, 2010
    Date of Patent: December 13, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Hiroyuki Ishii, Takuya Sato, Hidehiro Ando
  • Patent number: 8041381
    Abstract: A radio network controller includes a block error detection unit configured to receive a data block from the base station and to detect a block error, and a target SIR calculation unit configured to calculate a target SIR based on the detected block error rate. The target calculation unit sets a first time section, which indicates a time section from a detection of the block error to the notification of the target SIR is to the base station when the block error is detected, shorter than a second time section, which indicates a time section from the detection of the block error to the notification of the target SIR to the base station when the block error is not detected.
    Type: Grant
    Filed: January 10, 2007
    Date of Patent: October 18, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Masafumi Usuda, Anil Umesh, Hidehiro Ando, Takuya Sato, Shinichi Sasaki, Kouji Makino
  • Publication number: 20110142102
    Abstract: In this invention, a channel estimation value of data symbols of a data channel is calculated by weighting and averaging pilot symbols in a parallel time multiplexing method. Also, a channel estimation value of data symbols during each data symbol interval is calculated by dividing data symbols in a slot into a plurality of data symbol intervals, selecting pilot symbols suitable for calculation of a channel estimation value of data symbols during each data symbol interval and weighting and averaging that pilot symbols. Also, a fading frequency is detected based on an inner product value of pilot symbols. Weighting factors are changed based on the detected fading frequency. Also, a channel estimation value is calculated by weighting and averaging pilot signals using a plurality of weighting sequences. The calculated channel estimation value is used to demodulate received data. The output data with the highest quality is selected by judging reliability of these plurality of demodulated data.
    Type: Application
    Filed: February 23, 2011
    Publication date: June 16, 2011
    Applicant: NTT DoCoMo, Inc.
    Inventors: Yukihiko Okumura, Hidehiro Ando, Masafumi Usuda, Yoshihiro Ishikawa, Seizo Onoe
  • Patent number: 7929592
    Abstract: A channel estimation value of data symbols of a data channel is calculated by weighting and averaging pilot symbols in a parallel time multiplexing method. Also, a channel estimation value of data symbols during each data symbol interval is calculated by dividing data symbols in a slot into a plurality of data symbol intervals, selecting pilot symbols suitable for calculation of a channel estimation value of data symbols during each data symbol interval and weighting and averaging that pilot symbols. Also, a fading frequency is detected based on an inner product value of pilot symbols. Weighting factors are changed based on the detected fading frequency. Also, a channel estimation value is calculated by weighting and averaging pilot signals using a plurality of weighting sequences. The calculated channel estimation value is used to demodulate received data.
    Type: Grant
    Filed: March 31, 2000
    Date of Patent: April 19, 2011
    Assignee: NTT Docomo, Inc.
    Inventors: Yukihiko Okumura, Hidehiro Ando, Masafumi Usuda, Yoshihiro Ishikawa, Seizo Onoe
  • Patent number: 7920639
    Abstract: When a closed loop transmission diversity control is performed by controlling the phase of the transmission signals from the plurality of antennas according to feedback information noticed by the mobile station to transmit the signals, an antenna verification on-off control unit 370 controls the on-off of an antenna verification process of estimating the phase of the transmission signals from the plurality of antennas according to the information about the channel of the signals transmitted in the uplink from the mobile station to a radio base station. Thus, depending on the channel type (for example, a packet channel, a voice channel, etc.), the on-off control is performed on the antenna verification process, thereby performing easier and more appropriate control and improving the quality of a channel.
    Type: Grant
    Filed: July 20, 2006
    Date of Patent: April 5, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Hiroyuki Ishii, Takuya Sato, Hidehiro Ando
  • Publication number: 20100222094
    Abstract: The radio network controller 30 includes a block error detection unit 31 configured to receive a data block from the base station 20 and to detect a block error, and a target SIR calculation unit 32 configured to calculate a target SIR based on the detected block error rate. The target calculation unit 32 sets the first time section, which indicates a time section from a detection of the block error to the notification of the target SIR is to the base station 20 when the block error is detected, shorter than a second time section, which indicates a time section from the detection of the block error to the notification of the target SIR to the base station 20 when the block error is not detected.
    Type: Application
    Filed: January 10, 2007
    Publication date: September 2, 2010
    Applicant: NTT DoCoMo Inc.
    Inventors: Masafumi Usuda, Anil Umesh, Hidehiro Ando, Takuya Sato, Shinichi Sasaki, Kouji Makino
  • Publication number: 20100151812
    Abstract: When a closed loop transmission diversity control is performed by controlling the phase of the transmission signals from the plurality of antennas according to feedback information noticed by the mobile station to transmit the signals, an antenna verification on-off control unit 370 controls the on-off of an antenna verification process of estimating the phase of the transmission signals from the plurality of antennas according to the information about the channel of the signals transmitted in the uplink from the mobile station to a radio base station. Thus, depending on the channel type (for example, a packet channel, a voice channel, etc.), the on-off control is performed on the antenna verification process, thereby performing easier and more appropriate control and improving the quality of a channel.
    Type: Application
    Filed: February 23, 2010
    Publication date: June 17, 2010
    Applicant: NTT DoCoMo, Inc.
    Inventors: Hiroyuki Ishii, Takuya Sato, Hidehiro Ando
  • Publication number: 20100048214
    Abstract: A radio network controller includes: a determination unit configured to determine a transmit diversity method to be used to transmit a signal from a base station to a mobile station, in accordance with a soft handover status of the mobile station; and an instruction/notification unit configured to instruct the transmit diversity method to the base station, in accordance with the determination result by the determination unit.
    Type: Application
    Filed: December 13, 2005
    Publication date: February 25, 2010
    Applicant: NTT DoCoMo, Inc.
    Inventors: Masafumi Usuda, Takehiro Nakamura, Hidehiro Ando, Takuya Sato, Hiroyuki Ishii
  • Patent number: 7613432
    Abstract: A mobile communication system controls switching a transmission diversity system for each channel, and improves the quality of the channel. When the channel type in an uplink is a channel for transmitting voice, open loop transmission diversity is used (steps S1?S3). When the channel type in an uplink is a channel for transmitting a packet, closed loop transmission diversity is used (steps S1?S2). Since the open loop transmission diversity or the closed loop transmission diversity which ever is more appropriate can be used, a transmission diversity system can be appropriately switched for each channel, thereby improving the quality of the channel.
    Type: Grant
    Filed: July 27, 2006
    Date of Patent: November 3, 2009
    Assignee: NTT DoCoMo, Inc.
    Inventors: Hiroyuki Ishii, Takuya Sato, Hidehiro Ando
  • Publication number: 20080165757
    Abstract: An effective data multiplexing method wherein an error correction ability is exerted at the maximum so that data transmission quality is improved and a data transmitting method in which an interleaving process applicable to data transmission using interpolation pilot signal is performed are provided. The data multiplexing method includes the steps of: coding input data for each input channel; multiplexing said data which is coded; performing an interleaving process on said data which is multiplexed; and outputting said data. In the data transmitting method, when an interleaving process is performed, an interleaver is used in which the number of columns of the interleaver is twice as many as the number of slots of a frame.
    Type: Application
    Filed: March 7, 2008
    Publication date: July 10, 2008
    Applicant: NTT DoCoMo, Inc
    Inventors: Yukihiko OKUMURA, Hidehiro Ando
  • Patent number: 7366536
    Abstract: A downlink user data signal destined for a specific mobile station (4-1) is always transmitted from a single base station while a plurality of base stations (3-1, 3-2, 3-3, . . . ) being switched from one to another. A first downlink signal destined for the mobile station (4-1) is transmitted from one or a plurality of base stations through a first downlink radio channel (downlink A-DPCR). The transmission power of a second downlink radio channel (PDSCH, HS-SCCH) for transmitting a second downlink signal from the base station (3-1) to the mobile station (4-1) is provided with an offset relative to the transmission power of the first downlink radio channel from the base station (3-1) to the mobile station (4-1), thereby linking the transmission power of the second downlink radio channel with the transmission power of the first downlink radio channel. If the number of diversity branches, i.e.
    Type: Grant
    Filed: September 20, 2002
    Date of Patent: April 29, 2008
    Assignee: NTT DoCoMo, Inc.
    Inventors: Takahiro Hayashi, Yoshihiro Ishikawa, Mikio Iwamura, Hidehiro Ando, Takehiro Nakamura
  • Patent number: 7342915
    Abstract: An effective data multiplexing method wherein an error correction ability is exerted at the maximum so that data transmission quality is improved and a data transmitting method in which an interleaving process applicable to data transmission using interpolation pilot signal is performed are provided. The data multiplexing method includes the steps of: coding input data for each input channel; multiplexing said data which is coded; performing an interleaving process on said data which is multiplexed; and outputting said data. In the data transmitting method, when an interleaving process is performed, an interleaver is used in which the number of columns of the interleaver is twice as many as the number of slots of a frame.
    Type: Grant
    Filed: October 25, 2006
    Date of Patent: March 11, 2008
    Assignee: NTT DoCoMo, Inc.
    Inventors: Yukihiko Okumura, Hidehiro Ando
  • Patent number: 7327718
    Abstract: An effective data multiplexing method wherein an error correction ability is exerted at the maximum so that data transmission quality is improved and a data transmitting method in which an interleaving process applicable to data transmission using interpolation pilot signal is performed are provided. The data multiplexing method includes the steps of: coding input data for each input channel; multiplexing said data which is coded; performing an interleaving process on said data which is multiplexed; and outputting said data. In the data transmitting method, when an interleaving process is performed, an interleaver is used in which the number of columns of the interleaver is twice as many as the number of slots of a frame.
    Type: Grant
    Filed: March 27, 2007
    Date of Patent: February 5, 2008
    Assignee: NTT DoCoMo, Inc.
    Inventors: Yukihiko Okumura, Hidehiro Ando
  • Publication number: 20070286153
    Abstract: An effective data multiplexing method wherein an error correction ability is exerted at the maximum so that data transmission quality is improved and a data transmitting method in which an interleaving process applicable to data transmission using interpolation pilot signal is performed are provided. The data multiplexing method includes the steps of: coding input data for each input channel; multiplexing said data which is coded; performing an interleaving process on said data which is multiplexed; and outputting said data. In the data transmitting method, when an interleaving process is performed, an interleaver is used in which the number of columns of the interleaver is twice as many as the number of slots of a frame.
    Type: Application
    Filed: March 27, 2007
    Publication date: December 13, 2007
    Applicant: NTT DoCoMo, Inc
    Inventors: Yukihiko Okumura, Hidehiro Ando
  • Patent number: 7301991
    Abstract: Fading frequency decision device and method are provided. An inner product value of pilot symbols which are time multiplexed in a control channel which is parallel multiplexed with a data channel, an inner product value of pilot symbols in a channel in which data symbols and pilot symbols are time multiplexed, or an inner product value of pilot symbols of a pilot channel which is parallel multiplexed with a data channel is calculated. A fading frequency is decided based on the calculated inner product value.
    Type: Grant
    Filed: August 1, 2005
    Date of Patent: November 27, 2007
    Assignee: NTT DoCoMo, Inc.
    Inventors: Yukihiko Okumura, Hidehiro Ando, Masafumi Usuda, Yoshihiro Ishikawa, Seizo Onoe
  • Publication number: 20070036204
    Abstract: When a closed loop transmission diversity control is performed by controlling the phase of the transmission signals from the plurality of antennas according to feedback information noticed by the mobile station to transmit the signals, an antenna verification on-off control unit 370 controls the on-off of an antenna verification process of estimating the phase of the transmission signals from the plurality of antennas according to the information about the channel of the signals transmitted in the uplink from the mobile station to a radio base station. Thus, depending on the channel type (for example, a packet channel, a voice channel, etc.), the on-off control is performed on the antenna verification process, thereby performing easier and more appropriate control and improving the quality of a channel.
    Type: Application
    Filed: July 20, 2006
    Publication date: February 15, 2007
    Applicant: NTT DoCoMo, Inc.
    Inventors: Hiroyuki Ishii, Takuya Sato, Hidehiro Ando