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).
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Patent number: 8737224Abstract: 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: GrantFiled: July 2, 2010Date of Patent: May 27, 2014Assignee: NTT DoCoMo, Inc.Inventors: Takahiro Hayashi, Masafumi Masuda, Hidehiro Ando, Takaaki Sato, Yoshiyuki Yasuda
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Patent number: 8615245Abstract: 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: GrantFiled: December 13, 2005Date of Patent: December 24, 2013Assignee: NTT DoCoMo, Inc.Inventors: Masafumi Usuda, Takehiro Nakamura, Hidehiro Ando, Takuya Sato, Hiroyuki Ishii
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Patent number: 8295332Abstract: 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: GrantFiled: February 23, 2011Date of Patent: October 23, 2012Assignee: NTT DoCoMo, Inc.Inventors: Yukihiko Okumura, Hidehiro Ando, Masafumi Usuda, Yoshihiro Ishikawa, Seizo Onoe
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Publication number: 20120155392Abstract: 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: ApplicationFiled: July 2, 2010Publication date: June 21, 2012Applicant: NTT DOCOMO, INC.Inventors: Takahiro Hayashi, Masafumi Masuda, Hidehiro Ando, Takaaki Sato, Yoshiyuki Yasuda
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Patent number: 8077794Abstract: 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: GrantFiled: February 23, 2010Date of Patent: December 13, 2011Assignee: NTT DoCoMo, Inc.Inventors: Hiroyuki Ishii, Takuya Sato, Hidehiro Ando
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Patent number: 8041381Abstract: 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: GrantFiled: January 10, 2007Date of Patent: October 18, 2011Assignee: NTT DoCoMo, Inc.Inventors: Masafumi Usuda, Anil Umesh, Hidehiro Ando, Takuya Sato, Shinichi Sasaki, Kouji Makino
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Publication number: 20110142102Abstract: 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: ApplicationFiled: February 23, 2011Publication date: June 16, 2011Applicant: NTT DoCoMo, Inc.Inventors: Yukihiko Okumura, Hidehiro Ando, Masafumi Usuda, Yoshihiro Ishikawa, Seizo Onoe
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Patent number: 7929592Abstract: 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: GrantFiled: March 31, 2000Date of Patent: April 19, 2011Assignee: NTT Docomo, Inc.Inventors: Yukihiko Okumura, Hidehiro Ando, Masafumi Usuda, Yoshihiro Ishikawa, Seizo Onoe
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Patent number: 7920639Abstract: 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: GrantFiled: July 20, 2006Date of Patent: April 5, 2011Assignee: NTT DoCoMo, Inc.Inventors: Hiroyuki Ishii, Takuya Sato, Hidehiro Ando
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Publication number: 20100222094Abstract: 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: ApplicationFiled: January 10, 2007Publication date: September 2, 2010Applicant: NTT DoCoMo Inc.Inventors: Masafumi Usuda, Anil Umesh, Hidehiro Ando, Takuya Sato, Shinichi Sasaki, Kouji Makino
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Publication number: 20100151812Abstract: 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: ApplicationFiled: February 23, 2010Publication date: June 17, 2010Applicant: NTT DoCoMo, Inc.Inventors: Hiroyuki Ishii, Takuya Sato, Hidehiro Ando
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Publication number: 20100048214Abstract: 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: ApplicationFiled: December 13, 2005Publication date: February 25, 2010Applicant: NTT DoCoMo, Inc.Inventors: Masafumi Usuda, Takehiro Nakamura, Hidehiro Ando, Takuya Sato, Hiroyuki Ishii
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Patent number: 7613432Abstract: 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: GrantFiled: July 27, 2006Date of Patent: November 3, 2009Assignee: NTT DoCoMo, Inc.Inventors: Hiroyuki Ishii, Takuya Sato, Hidehiro Ando
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Publication number: 20080165757Abstract: 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: ApplicationFiled: March 7, 2008Publication date: July 10, 2008Applicant: NTT DoCoMo, IncInventors: Yukihiko OKUMURA, Hidehiro Ando
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Patent number: 7366536Abstract: 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: GrantFiled: September 20, 2002Date of Patent: April 29, 2008Assignee: NTT DoCoMo, Inc.Inventors: Takahiro Hayashi, Yoshihiro Ishikawa, Mikio Iwamura, Hidehiro Ando, Takehiro Nakamura
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Patent number: 7342915Abstract: 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: GrantFiled: October 25, 2006Date of Patent: March 11, 2008Assignee: NTT DoCoMo, Inc.Inventors: Yukihiko Okumura, Hidehiro Ando
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Patent number: 7327718Abstract: 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: GrantFiled: March 27, 2007Date of Patent: February 5, 2008Assignee: NTT DoCoMo, Inc.Inventors: Yukihiko Okumura, Hidehiro Ando
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Publication number: 20070286153Abstract: 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: ApplicationFiled: March 27, 2007Publication date: December 13, 2007Applicant: NTT DoCoMo, IncInventors: Yukihiko Okumura, Hidehiro Ando
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Patent number: 7301991Abstract: 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: GrantFiled: August 1, 2005Date of Patent: November 27, 2007Assignee: NTT DoCoMo, Inc.Inventors: Yukihiko Okumura, Hidehiro Ando, Masafumi Usuda, Yoshihiro Ishikawa, Seizo Onoe
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Publication number: 20070036204Abstract: 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: ApplicationFiled: July 20, 2006Publication date: February 15, 2007Applicant: NTT DoCoMo, Inc.Inventors: Hiroyuki Ishii, Takuya Sato, Hidehiro Ando