Patents by Inventor Junichiro Hagiwara
Junichiro Hagiwara 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: 8542835Abstract: When a network pages the temporary user mobile identifier of a mobile station, the mobile station sends a response to the network. Next, the network checks the authenticity of the user using a ciphering key, corresponding to the temporary user mobile identifier and a random number. If the temporary user mobile identifier is authenticated, a normal incoming call acceptance procedure is executed. If the mobile station is authenticated although the temporary user mobile identifier is wrong, the network reassigns a new temporary user mobile identifier to the mobile station and stops the current communication. In communication, the network and the mobile station mutually notify encipherment-onset time and negotiate about encipherment manner with each other. In addition, diversity handover is commenced upon a call attempt. Furthermore, if a branch replacement is necessary, the current branch is replaced by new branches capable of executing the diversity handover.Type: GrantFiled: February 5, 2009Date of Patent: September 24, 2013Assignee: NTT DoCoMo, Inc.Inventors: Motoshi Tamura, Mutsumaru Miki, Akiko Okamoto, Kenya Kusunose, Akihiro Uchikoshi, Daisuke Igarashi, Katsuhiko Yamagata, Takaaki Sato, Junichiro Hagiwara, Yasuyuki Watanabe, Takuya Hamajima, Masafumi Hata, Nobutaka Ishikawa, Yoshiyuki Yasuda, Kazufumi Yunoki, Nobuhide Uchiyama
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Publication number: 20130208652Abstract: A relay station for relaying a radio signal between a mobile station and a base station includes a relay station information generating unit configured to generate relay station information used by the base station to select a switching center to be connected to the relay station. The relay station also includes a message generating unit configured to generate a message including the relay station information generated by the relay station information generating unit, and a transmitting unit configured to transmit the message generated by the message generating unit to the base station.Type: ApplicationFiled: September 21, 2011Publication date: August 15, 2013Applicant: NTT DOCOMO, INC.Inventors: Yasufumi Morioka, Akira Yamada, Hideaki Takahashi, Mikio Iwamura, Junichiro Hagiwara
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Publication number: 20130208653Abstract: A relay node of a communication system includes a communication unit that initiates a session by executing an initial connection procedure for retrieving a cell list indicating one or more donor base station candidates from a maintenance node after establishment of an initial communication link among the relay node, a base station, and a switching center, and for establishing a communication link to a donor base station in the cell list and a switching center connected to the donor base station; a storing unit that stores the cell list; and a reconnection control unit that selects, when a radio link with the donor base station is lost, a donor base station satisfying a predetermined criterion in the cell list, and that causes the communication unit to establish a communication link to the selected donor base station and a switching center connected to the selected donor base station.Type: ApplicationFiled: October 31, 2011Publication date: August 15, 2013Applicant: NTT DOCOMO, INC.Inventors: Yasufumi Morioka, Akira Yamada, Hideaki Takahashi, Mikio Iwamura, Junichiro Hagiwara
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Publication number: 20130201897Abstract: A base station generates first setting information commonly used for establishing a logical path for communication with a user apparatus and for establishing a logical path for communication with a relay station, and second setting information used only for establishing the logical path for communication with the relay station, and transmits a second RRC message including the second setting information to the relay station after transmitting a first RRC message including the first setting information to the relay station. The first setting information includes information indicating a priority of a radio bearer in the logical path, information indicating usage of resources in SPS, information indicating resources of SRS, configuration information in a MAC sublayer, and information on change of a security encryption key in handover, and the second setting information includes at least system information and MBSFN information.Type: ApplicationFiled: August 10, 2011Publication date: August 8, 2013Applicant: NTT DOCOMO, INC.Inventors: Yasufumi Morioka, Akira Yamada, Junichiro Hagiwara, Hideaki Takahashi, Mikio Iwamura
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Publication number: 20130203342Abstract: A relay station includes a signal generation unit configured to generate a signal in the relay station and a receiving unit configured to receive a signal from a first communication station. The relay station further includes a signal generating node identifying unit configured to identify whether a signal to be transmitted to a second communication station is a received signal received from the first communication station or a generated signal generated by the signal generation unit. The relay station further includes a signal transmission unit configured to transmit both or one of the received signal and the generated signal associated with a radio bearer to the second communication station.Type: ApplicationFiled: September 27, 2011Publication date: August 8, 2013Applicant: NTT DOCOMO, INC.Inventors: Yasufumi Morioka, Akira Yamada, Hideaki Takahashi, Mikio Iwamura, Junichiro Hagiwara
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Publication number: 20130184006Abstract: An area range estimation device includes a first location information acquisition unit that acquires first location information containing terminal identification information identifying a mobile terminal and area identification information identifying a location area of the mobile terminal, a second location information acquisition unit that acquires second location information containing the terminal identification information and location information indicating a location of the mobile terminal, a correspondence information generation unit that generates correspondence information based on the area identification information and the location information by using the acquired first location information and second location information, and an area range estimation unit that estimates a range of an area identified by the area identification information based on the generated correspondence information.Type: ApplicationFiled: February 10, 2012Publication date: July 18, 2013Applicant: NTT DOCOMO, INC.Inventors: Takayasu Yamaguchi, Masayuki Terada, Junichiro Hagiwara, Ichiro Okajima
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Patent number: 8483038Abstract: The present invention is to provide a communication channel with a low inter-cell interference while suppressing variation in the amount of inter-cell interference. Provided is a base station arranged in a radio communication system configured to implement a frequency division multiple access method by using a frequency division multiplexing method as a modulation method, and configured of cells each divided into an inner region and an outer region. The base station includes an allocation controller configured to perform subchannelization using a perfectly-orthogonal channel in the outer region of the cell, and to perform subchannelization using a quasi-orthogonal channel in the inner region of the cell.Type: GrantFiled: December 4, 2007Date of Patent: July 9, 2013Assignee: NTT DoCoMo, Inc.Inventors: Hiromasa Fujii, Hitoshi Yoshino, Junichiro Hagiwara
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Patent number: 8385861Abstract: A disclosed radio communication apparatus transmits a radio signal to multiple users via multiple transmit antenna groups at appropriate transmit power levels, each of the transmit antenna groups including one or more transmit antennas, the transmit antenna groups having respective transmit power constraints. The apparatus includes a precoding unit configured to perform precoding on signals modulated for individual users and generate transmit weights, an optimum transmit power calculation unit configured to receive the transmit weights from the precoding unit and use components of the transmit weights and respective transmit power limit values for the transmit antenna groups to calculate an initial value for a transmit power optimization problem for calculation of the appropriate transmit power levels for the users, and a transmission unit configured to transmit radio signals at the calculated transmit power levels.Type: GrantFiled: April 29, 2009Date of Patent: February 26, 2013Assignee: NTT DoCoMo, Inc.Inventors: Yusuke Ohwatari, Anass Benjebbour, Tomoyuki Ooya, Junichiro Hagiwara
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Patent number: 8331935Abstract: When a new call occurs to or from the mobile station capable of treating a plurality of calls simultaneously, the mobile station uses the same branch structure and the same communication frequency band for all of calls. Additionally, when a new call occurs to or from the mobile station capable of treating a plurality of calls simultaneously, a branch structure and a communication frequency band, which can continue all of the calls, are selected and used.Type: GrantFiled: February 3, 2009Date of Patent: December 11, 2012Assignee: NTT DoCoMo, Inc.Inventors: Motoshi Tamura, Mutsumaru Miki, Akiko Okamoto, Kenya Kusunose, Akihiro Uchikoshi, Daisuke Igarashi, Katsuhiko Yamagata, Takaaki Sato, Junichiro Hagiwara, Yasuyuki Watanabe, Takuya Hamajima, Masafumi Hata, Nobutaka Ishikawa, Yoshiyuki Yasuda, Kazufumi Yunoki, Nobuhide Uchiyama
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Patent number: 8326245Abstract: A disclosed radio communication apparatus transmits a radio signal to multiple users via multiple transmit antenna groups at appropriate transmit power levels, each of the transmit antenna groups including one or more transmit antennas, the transmit antenna groups having respective transmit power constraints. The apparatus includes a precoding unit configured to perform precoding on signals modulated for individual users and generate transmit weights, an optimum transmit power calculation unit configured to receive the transmit weights from the precoding unit and use components of the transmit weights and respective transmit power limit values for the transmit antenna groups to calculate an initial value for a transmit power optimization problem for calculation of the appropriate transmit power levels for the users, and a transmission unit configured to transmit radio signals at the calculated transmit power levels.Type: GrantFiled: April 29, 2009Date of Patent: December 4, 2012Assignee: NTT DoCoMo, Inc.Inventors: Yusuke Ohwatari, Anass Benjebbour, Tomoyuki Ooya, Junichiro Hagiwara
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Patent number: 8275133Abstract: When a network pages the temporary user mobile identifier of a mobile station, the mobile station sends a response to the network. Next, the network checks the authenticity of the user using a ciphering key, corresponding to the temporary user mobile identifier and a random number. If the temporary user mobile identifier is authenticated, a normal incoming call acceptance procedure is executed. If the mobile station is authenticated although the temporary user mobile identifier is wrong, the network reassigns a new temporary user mobile identifier to the mobile station and stops the current communication. In communication, the network and the mobile station mutually notify encipherment-onset time and negotiate about encipherment manner with each other. In addition, diversity handover is commenced upon a call attempt. Furthermore, if a branch replacement is necessary, the current branch is replaced by new branches capable of executing the diversity handover.Type: GrantFiled: March 30, 2006Date of Patent: September 25, 2012Assignee: NTT Docomo, Inc.Inventors: Motoshi Tamura, Mutsumaru Miki, Akiko Okamoto, Kenya Kusunose, Akihiro Uchikoshi, Daisuke Igarashi, Katsuhiko Yamagata, Takaaki Sato, Junichiro Hagiwara, Yasuyuki Watanabe, Takuya Hamajima, Masafumi Hata, Nobutaka Ishikawa, Yoshiyuki Yasuda, Kazufumi Yunoki, Nobuhide Uchiyama
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Patent number: 8259675Abstract: When a network pages the temporary user mobile identifier of a mobile station, the mobile station sends a response to the network. Next, the network checks the authenticity of the user using a ciphering key, corresponding to the temporary user mobile identifier and a random number. If the temporary user mobile identifier is authenticated, a normal incoming call acceptance procedure is executed. If the mobile station is authenticated although the temporary user mobile identifier is wrong, the network reassigns a new temporary user mobile identifier to the mobile station and stops the current communication. In communication, the network and the mobile station mutually notify encipherment-onset time and negotiate about encipherment manner with each other. In addition, diversity handover is commenced upon a call attempt. Furthermore, if a branch replacement is necessary, the current branch is replaced by new branches capable of executing the diversity handover.Type: GrantFiled: February 4, 2009Date of Patent: September 4, 2012Assignee: NTT DoCoMo, Inc.Inventors: Motoshi Tamura, Mutsumaru Miki, Akiko Okamoto, Kenya Kusunose, Akihiro Uchikoshi, Daisuke Igarashi, Katsuhiko Yamagata, Takaaki Sato, Junichiro Hagiwara, Yasuyuki Watanabe, Takuya Hamajima, Masafumi Hata, Nobutaka Ishikawa, Yoshiyuki Yasuda, Kazufumi Yunoki, Nobuhide Uchiyama
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Patent number: 8224369Abstract: A disclosed radio communication apparatus includes a precoding unit, a optimum transmit power calculation unit and a transmission unit. The optimum transmit power calculation unit receives the transmit weight related information from the precoding unit and calculates a transmit power level to optimize an objective function in accordance with an interior point method. The objective function results from addition of a barrier function adjusted with a barrier parameter to an original objective function associated with a constrained optimization problem. The original objective function includes a function of respective channel capacities for individual users derived from the transmit weight related information. The optimum transmit power calculation unit adaptively updates a logarithm of the barrier parameter and uses a gradient obtained through a high-order derivative with the logarithm of the barrier parameter to calculate the transmit power level to optimize the resulting objective function.Type: GrantFiled: April 29, 2009Date of Patent: July 17, 2012Assignee: NTT DoCoMo, Inc.Inventors: Yusuke Ohwatari, Anass Benjebbour, Tomoyuki Ooya, Junichiro Hagiwara
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Patent number: 8200169Abstract: The present invention has an object of providing a transmitter apparatus, a mobile communication system, a base station and a communication enable signal transmitter unit, which can prioritize communications of a mobile station in a priority communication system over communications of a mobile station in a non-priority communication system, in a network where the priority communication system and the non-priority communication system coexist in the same communication area.Type: GrantFiled: February 27, 2008Date of Patent: June 12, 2012Assignee: NTT DoCoMo, Inc.Inventors: Hiromasa Fujii, Junichiro Hagiwara, Hitoshi Yoshino
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Patent number: 8185158Abstract: When a network pages the temporary user mobile identifier of a mobile station, the mobile station sends a response to the network. Next, the network checks the authenticity of the user using a ciphering key, corresponding to the temporary user mobile identifier and a random number. If the temporary user mobile identifier is authenticated, a normal incoming call acceptance procedure is executed. If the mobile station is authenticated although the temporary user mobile identifier is wrong, the network reassigns a new temporary user mobile identifier to the mobile station and stops the current communication. In communication, the network and the mobile station mutually notify encipherment-onset time and negotiate about encipherment manner with each other. In addition, diversity handover is commenced upon a call attempt. Furthermore, if a branch replacement is necessary, the current branch is replaced by new branches capable of executing the diversity handover.Type: GrantFiled: April 9, 2009Date of Patent: May 22, 2012Assignee: NTT Mobile Communications Network, Inc.Inventors: Motoshi Tamura, Mutsumaru Miki, Akiko Okamoto, Kenya Kusunose, Akihiro Uchikoshi, Daisuke Igarashi, Katsuhiko Yamagata, Takaaki Sato, Junichiro Hagiwara, Yasuyuki Watanabe, Takuya Hamajima, Masafumi Hata, Nobutaka Ishikawa, Yoshiyuki Yasuda, Kazufumi Yunoki, Nobuhide Uchiyama
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Patent number: 8126498Abstract: A disclosed radio communication apparatus includes a precoding unit, a optimum transmit power calculation unit and a transmission unit. The optimum transmit power calculation unit receives the transmit weight related information from the precoding unit and calculates a transmit power level to optimize an objective function in accordance with an interior point method. The objective function results from addition of a barrier function adjusted with a barrier parameter to an original objective function associated with a constrained optimization problem. The original objective function includes a function of respective channel capacities for individual users derived from the transmit weight related information. The optimum transmit power calculation unit adaptively updates a logarithm of the barrier parameter and uses a gradient obtained through a high-order derivative with the logarithm of the barrier parameter to calculate the transmit power level to optimize the resulting objective function.Type: GrantFiled: April 29, 2009Date of Patent: February 28, 2012Assignee: NTT DoCoMo, Inc.Inventors: Yusuke Ohwatari, Anass Benjebbour, Tomoyuki Ooya, Junichiro Hagiwara
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Patent number: 8095169Abstract: A disclosed radio communication apparatus includes a preceding unit configured to precode multiple streams, a splitting unit configured to split the precoded streams into two or more stream sets each including one or more streams, a sub power optimization unit configured to execute an iterative transmit power optimization algorithm on each of the split stream sets to determine respective transmit power levels for the individual stream sets, a power optimization unit configured to execute the iterative transmit power optimization algorithm by using the determined transmit power levels as initial values for the iterative transmit power optimization algorithm to determine respective transmit power levels for the individual streams, and a transmission unit configured to transmit radio signals from individual transmit antennas at the determined transmit power levels.Type: GrantFiled: April 29, 2009Date of Patent: January 10, 2012Assignee: NTT DoCoMo, Inc.Inventors: Yusuke Ohwatari, Anass Benjebbour, Tomoyuki Ooya, Junichiro Hagiwara
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Patent number: 8005120Abstract: A base station including a transmitting and receiving amplifier for amplifying CDMA signals exchanged with a mobile station; a radio stage connected to the transmitting and receiving amplifier for carrying out D/A conversion of a transmitted signal that undergoes baseband spreading, followed by quadrature modulation, and for carrying out quasi-coherent detection of a received signal, followed by A/D conversion; a baseband signal processor connected with the radio stage for carrying out baseband signal processing of the transmitted signal and the received signal; a transmission interface connected with the baseband signal processor for implementing interface with external channels; and a base station controller for carrying out control such as management of radio channels and establishment and release of the radio channels. The base station communicates with the external channels by mapping logical channels into physical channels. The CDMA signals are spread using a short code and a long code.Type: GrantFiled: September 29, 2003Date of Patent: August 23, 2011Assignee: NTT DoCoMo, Inc.Inventors: Takehiro Nakamura, Junichiro Hagiwara, Etsuhiro Nakano, Koji Ohno, Seizo Onoe, Akihiro Higashi, Motoshi Tamura, Masatomo Nakano, Hiroshi Kawakami, Hiroki Morikawa
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Patent number: 7953414Abstract: When a network pages the temporary user mobile identifier of a mobile station, the mobile station sends a response to the network. Next, the network checks the authenticity of the user using a ciphering key, corresponding to the temporary user mobile identifier and a random number. If the temporary user mobile identifier is authenticated, a normal incoming call acceptance procedure is executed. If the mobile station is authenticated although the temporary user mobile identifier is wrong, the network reassigns a new temporary user mobile identifier to the mobile station and stops the current communication. In communication, the network and the mobile station mutually notify encipherment-onset time and negotiate about encipherment manner with each other. In addition, diversity handover is commenced upon a call attempt. Furthermore, if a branch replacement is necessary, the current branch is replaced by new branches capable of executing the diversity handover.Type: GrantFiled: January 28, 2009Date of Patent: May 31, 2011Assignee: NTT DocomoInventors: Motoshi Tamura, Mutsumaru Miki, Akiko Okamoto, Kenya Kusunose, Akihiro Uchikoshi, Daisuke Igarashi, Katsuhiko Yamagata, Takaaki Sato, Junichiro Hagiwara, Yasuyuki Watanabe, Takuya Hamajima, Masafumi Hata, Nobutaka Ishikawa, Yoshiyuki Yasuda, Kazufumi Yunoki, Nobuhide Uchiyama
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Publication number: 20110080884Abstract: A coordinated transmission method of the invention has the steps of selecting a directional pattern corresponding to an area in which a radio terminal locates, from among a plurality of directional patterns determined respectively corresponding to a plurality of resources in frequency domains where the plurality of directional patterns is configured so that a plurality of radio base stations surrounding the area transmits, to the area, directional beams of same frequency domain resources to face one another, while not transmitting the directional beams of the same frequency domain resources using the same frequency domain resources to areas adjacent to the area, and of distributing a signal to transmit to the radio terminal according to the selected directional pattern, determining a frequency domain and directions of directional beams regarding the distributed signal, and delivering the signal to each of the plurality of radio base stations that simultaneously transmits the signal to the radio terminal.Type: ApplicationFiled: October 1, 2010Publication date: April 7, 2011Applicant: NTT DOCOMO, INC.Inventors: Yusuke Ohwatari, Anass Benjebbour, Yukihiko Okumura, Junichiro Hagiwara