Patents by Inventor Yoshiaki Ofuji
Yoshiaki Ofuji 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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Publication number: 20130286995Abstract: A base station of a communication system includes a quality information retrieval unit that retrieves quality information indicating a radio channel state of user equipment, a threshold value determination unit that determines, for each of the user equipment, a threshold value for at least one of a data retention amount and a data retention time period, depending on the quality information, a scheduler that calculates a scheduling coefficient for the user equipment for which at least the one of the data retention amount and the data retention time period exceeds the threshold value, and that allocates a radio resource to the user equipment at least in accordance with a magnitude of the scheduling coefficient, and a notification unit that reports to the user equipment that the radio resource is allocated.Type: ApplicationFiled: March 12, 2012Publication date: October 31, 2013Applicant: NTT DOCOMO, INC.Inventors: Tooru Uchino, Mikio Iwamura, Yoshiaki Ofuji, Hiroyuki Ishii, Anil Umesh, Naoto Ookubo, Kohei Kiyoshima
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Patent number: 8520608Abstract: A mobile communication system in which a finite number of reference signal sequences used for uplink channel estimation or the like are reused among multiple cells includes a determining unit configured to determine a frequency band used by user terminals to which a reference signal sequence with a predetermined sequence length is assigned in each of the cells within an interference area, wherein the frequency band is determined to be different from frequency bands used in the other cells.Type: GrantFiled: June 14, 2007Date of Patent: August 27, 2013Assignee: NTT DoCoMo, Inc.Inventors: Yoshiaki Ofuji, Kenichi Higuchi, Mamoru Sawahashi
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Patent number: 8442546Abstract: A radio base station (eNB) according to the present invention includes: a calculation unit (12) configured to calculate an adjusted value of a reception quality, based on the reception quality in a specific mobile station in at least one first resource block assigned to the specific mobile station in a PUSCH, and the number of resource elements assigned to transmission of dedicated control information in the first resource blocks; and a selection unit (13) configured to select, based on the adjusted value of the reception quality, the number of bits which can be transmitted and a modulation scheme that should be used in the first resource blocks.Type: GrantFiled: December 18, 2009Date of Patent: May 14, 2013Assignee: NTT DoCoMo, Inc.Inventors: Yoshiaki Ofuji, Hiroyuki Ishii, Naoto Okubo
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Patent number: 8400909Abstract: A disclosed transmission apparatus comprises a switching portion that switches radio access methods; a frequency domain signal generation portion that allocates a radio resource to a spread chip sequence on which one of a fast Fourier transformation and a series/parallel conversion is performed in accordance with the switched radio accessed method, so as to generate a signal in a frequency domain; and a transmission signal generation portion that performs a fast inverse Fourier transformation on the signal in the frequency domain so as to generate a transmission signal.Type: GrantFiled: November 17, 2010Date of Patent: March 19, 2013Assignee: NTT DoCoMo, Inc.Inventors: Yoshiaki Ofuji, Hiroyuki Atarashi, Kenichi Higuchi, Mamoru Sawahashi
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Publication number: 20130059595Abstract: A base station allocates a radio resource to a scheduling-target user based on a scheduling metric which is calculated for each of scheduling-target users and calculates the amount of available data for each user. When the radio resource is allocated to the scheduling-target user, the amount of data (Dassign) to be communicated using the allocated radio resource is subtracted from the amount of available data (Davailable) for the user. The amount of available data (Davailable) for each user within a cell is updated (min((Davailable+Dref), Dref)) to be less than or equal to a reference data amount in each control period (TAMBR). The scheduling-target user is selected based on the amount of available data for each user.Type: ApplicationFiled: April 7, 2011Publication date: March 7, 2013Applicant: NTT DOCOMO, INC.Inventors: Naoto Okubo, Yoshiaki Ofuji, Hiroyuki Ishii, Anil Umeshi, Kohei Kiyoshima, Tadashi Uchiyama
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Patent number: 8374162Abstract: A disclosed transmission device includes a frequency scheduling unit configured to allocate, to each user, either frequency blocks that are consecutive frequency subcarrier blocks obtained by dividing a system bandwidth or distributed frequency blocks that are frequency subcarrier blocks discretely distributed in the system bandwidth; and a mapping unit configured to assign transmission data to the frequency blocks or the distributed frequency blocks according to the allocation result. The frequency scheduling unit is configured to allocate the distributed frequency blocks using the frequency blocks as units and to allocate sub-blocks obtained by dividing the respective distributed frequency blocks.Type: GrantFiled: February 5, 2007Date of Patent: February 12, 2013Assignee: NTT DoCoMo, Inc.Inventors: Kenichi Higuchi, Yoshihisa Kishiyama, Yoshiaki Ofuji, Satoshi Nagata, Mamoru Sawahashi
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Patent number: 8345636Abstract: A base station includes a transmission method determining portion that determines whether to allow a mobile station to transmit a propagation path measuring signal by one of a multi-carrier method and a single carrier method; and a transmission method sending portion that sends information indicating the determined transmission method with the mobile station. A mobile station includes a data mapping portion that maps a signal sequence of a propagation path state measuring signal in accordance with transmission information that a base station sends in order to indicate the propagation path state measuring signal is transmitted by either one of a single carrier method and a multi-carrier method.Type: GrantFiled: March 19, 2007Date of Patent: January 1, 2013Assignee: NTT DoCoMo, Inc.Inventors: Yoshiaki Ofuji, Kenichi Higuchi, Mamoru Sawahashi
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Patent number: 8248990Abstract: A disclosed transmission device includes a frequency scheduling unit configured to allocate a resource block divided from a system bandwidth into blocks of consecutive frequency subcarriers or distributed-type resource blocks including discretely-distributed frequency subcarriers in a system bandwidth and divided from the resource block, assign locations and identification numbers of the distributed-type resource blocks divided by a predetermined division number with respect to each resource block, and determine the distributed-type resource blocks to be allocated to a user based on the assigned locations of the distributed-type resource blocks; a mapping unit configured to allocate transmission data to either the resource block or distributed-type resource blocks in accordance with the allocation; and a control information generating unit configured to generate control information with respect to a mobile station to which either the resource block or the distributed-type resource blocks are allocated based oType: GrantFiled: August 17, 2007Date of Patent: August 21, 2012Assignee: NTT DoCoMo, Inc.Inventors: Yoshiaki Ofuji, Kenichi Higuchi, Mamoru Sawahashi
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Patent number: 8195238Abstract: A disclosed paging method includes a random access channel generating step of, when a group including an own station is being paged based on a paging indicator channel (PICH) transmitted from a base station apparatus, generating a random access channel (RACH) including information indicating a response to the paging indicator channel (PICH) by a mobile station apparatus; a transmitting step of transmitting the random access channel (RACH) by the mobile station apparatus; a random access channel detecting step of detecting the random access channel (RACH) as the response to the paging indicator channel (PICH) by the base station apparatus; a paging information generation determining step of determining whether paging information is to be generated based on a detection result of the random access channel (RACH); and a paging information generating step of generating paging information based on the determination result.Type: GrantFiled: June 14, 2007Date of Patent: June 5, 2012Assignee: NTT DoCoMo, Inc.Inventors: Yoshiaki Ofuji, Yoshihisa Kishiyama, Kenichi Higuchi, Mamoru Sawahashi
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Patent number: 8169928Abstract: A channel quality information reporting method includes a setting step, wherein the number N of blocks for which the mobile station reports channel quality information among the M blocks is set in accordance with an amount of traffic; a reporting step, wherein the base station reports the number N of blocks to the mobile station; a receiving step, wherein the mobile station receives the number N of blocks from the base station; a selecting step, wherein the mobile station selects N pieces of channel quality information from M pieces of channel quality information corresponding to the M blocks; an averaging step, wherein the mobile station averages pieces of channel quality information excluding the selected N pieces of the channel quality information; and a reporting step, wherein the mobile station reports the N pieces of channel quality information and the averaged channel quality information to the base station.Type: GrantFiled: June 15, 2007Date of Patent: May 1, 2012Assignee: NTT DoCoMo, Inc.Inventors: Mikio Iwamura, Yoshiaki Ofuji, Minami Ishii
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Patent number: 8134966Abstract: A transmission device is disclosed that includes a frequency scheduling unit configured to allocate resource blocks as a unit to each user, the resource blocks being blocks of consecutive frequency subcarriers divided from a system bandwidth, constitute a first group including consecutive plural resource blocks, constitute plural second groups, each including one or more resource blocks of the plural resource blocks constituting each first group, and allocate the resource blocks of either the first group or one or more the second groups; a mapping unit configured to allocate transmission data to the resource blocks in accordance with the allocation; and a control information generating unit configured to generate control information with respect to a mobile station to which either the first group or one or more the second groups are allocated.Type: GrantFiled: August 13, 2007Date of Patent: March 13, 2012Assignee: NTT DoCoMo, Inc.Inventors: Satoshi Nagata, Yoshiaki Ofuji, Kenichi Higuchi, Mamoru Sawahashi
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Patent number: 8111766Abstract: An apparatus for generating sets of radio parameters includes a first deriving unit deriving a set of radio parameters for specifying a symbol including an effective symbol part with the same period as the effective symbol part specified by another set of radio parameters and a guard interval part with a different period from the guard interval part specified by the other set of radio parameters. The apparatus further includes a second deriving unit deriving a set of radio parameters so that an occupancy proportion of the guard interval part in a single symbol specified by another set of radio parameters is equal to an occupancy proportion of the guard interval part in a single symbol specified by the other set of radio parameters.Type: GrantFiled: June 20, 2011Date of Patent: February 7, 2012Assignee: NTT DoCoMo, Inc.Inventors: Mamoru Sawahashi, Kenichi Higuchi, Hiroyuki Atarashi, Motohiro Tanno, Yoshihisa Kishiyama, Yoshiaki Ofuji
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Publication number: 20110305152Abstract: A radio base station (eNB) includes: a calculation unit (12) configured to calculate an adjusted value of reception quality information, based on an average value of the reception quality information in the at least one first resource block assigned to a mobile station (UE) in a PDSCH, and the number of resource elements assigned within the first resource blocks as one of a radio resource for a downlink common channel and a radio resource for a PDCCH; and a selection unit (13) configured to select, based on the adjusted value of the reception quality information, a modulation scheme that should be used in the PDSCH and the number of bits that can be transmitted in each of the first resource block.Type: ApplicationFiled: December 18, 2009Publication date: December 15, 2011Applicant: NTT DOCOMO, INC.Inventors: Yoshiaki Ofuji, Hiroyuki Ishii, Naoto Okubo
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Publication number: 20110299466Abstract: A radio base station (eNB) according to the present invention includes: an RI acquisition unit (11) configured to acquire, from a mobile station (UE), an “RI” indicating number of streams determined by the mobile station (UE); an adjustment unit (12) configured to adjust the “RI” acquired by the RI acquisition unit (11), by using an offset value “RI offset” unique to the mobile station (UE); and a stream-number determination unit (13) configured to determine the number of streams to be simultaneously transmitted to the mobile station (UE), based on the “RI” adjusted by the adjustment unit (12).Type: ApplicationFiled: December 15, 2009Publication date: December 8, 2011Applicant: NTT DOCOMO, INC.Inventors: Yoshiaki Ofuji, Naoto Okubo
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Publication number: 20110292916Abstract: Provided are a radio packet type determining section that determines at least whether a radio packet is a first transmission packet that is allocated persistently at predetermined time intervals or a retransmission packet among radio packets transmitted to a radio communication terminal, a first transmission interval control section that controls a transmission interval of each first transmission packet so as to disperse the first transmission packet and a retransmission packet of a radio packet index different from that of the first transmission packet, a retransmission interval control section that controls a transmission interval of each retransmission packet, and a radio resource allocation section that performs allocation of radio resources based on the transmission interval of each first transmission packet and the transmission interval of each retransmission packet.Type: ApplicationFiled: May 25, 2011Publication date: December 1, 2011Applicant: NTT DOCOMO, INC.Inventors: Masashige Shirakabe, Kei Kikuiri, Akihito Hanaki, Yoshiaki Ofuji
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Publication number: 20110294439Abstract: A radio base station (eNB) according to the present invention includes: a calculation unit (12) configured to calculate an adjusted value of a reception quality, based on the reception quality in a specific mobile station in at least one first resource block assigned to the specific mobile station in a PUSCH, and the number of resource elements assigned to transmission of dedicated control information in the first resource blocks; and a selection unit (13) configured to select, based on the adjusted value of the reception quality, the number of bits which can be transmitted and a modulation scheme that should be used in the first resource blocks.Type: ApplicationFiled: December 18, 2009Publication date: December 1, 2011Applicant: NTT DOCOMO, INC.Inventors: Yoshiaki Ofuji, Hiroyuki Ishii, Naoto Okubo
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Publication number: 20110249764Abstract: An apparatus for generating sets of radio parameters includes a first deriving unit deriving a set of radio parameters for specifying a symbol including an effective symbol part with the same period as the effective symbol part specified by another set of radio parameters and a guard interval part with a different period from the guard interval part specified by the other set of radio parameters. The apparatus further includes a second deriving unit deriving a set of radio parameters so that an occupancy proportion of the guard interval part in a single symbol specified by another set of radio parameters is equal to an occupancy proportion of the guard interval part in a single symbol specified by the other set of radio parameters.Type: ApplicationFiled: June 20, 2011Publication date: October 13, 2011Applicant: NTT DOCOMO, INC.Inventors: Mamoru Sawahashi, Kenichi Higuchi, Hiroyuki Atarashi, Motohiro Tanno, Yoshihisa Kishiyama, Yoshiaki Ofuji
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Patent number: 8018898Abstract: One aspect of the present invention relates to a base station wherein either resource blocks resulting from division of a system bandwidth into blocks of consecutive frequency subcarriers or distributed type resource blocks consisting of frequency subcarriers discretely distributed within the system bandwidth and resulting from segmentation of the resource blocks into multiple resource blocks are assigned to mobile stations, the base station including: a scheduling unit configured to assign either the resource blocks or the distributed type resource blocks to the mobile stations at a predefined assignment cycle based on respective downlink reception channel states transmitted from the mobile stations.Type: GrantFiled: August 17, 2007Date of Patent: September 13, 2011Assignee: NTT DoCoMo, Inc.Inventors: Yoshiaki Ofuji, Kenichi Higuchi, Mamoru Sawahashi
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Patent number: 8000296Abstract: One aspect of the present invention relates to a base station wherein either resource blocks resulting from division of a system bandwidth into blocks of consecutive frequency subcarriers or distributed type resource blocks consisting of frequency subcarriers discretely distributed within the system bandwidth and resulting from segmentation of the resource blocks into multiple resource blocks are assigned to mobile stations, the base station including: a scheduling unit configured to assign either the resource blocks or the distributed type resource blocks to the mobile stations at a predefined assignment cycle based on respective downlink reception channel states transmitted from the mobile stations.Type: GrantFiled: March 4, 2011Date of Patent: August 16, 2011Assignee: NTT Docomo, Inc.Inventors: Yoshiaki Ofuji, Kenichi Higuchi, Mamoru Sawahashi
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Patent number: 7991064Abstract: An apparatus for generating sets of radio parameters includes a first deriving unit deriving a set of radio parameters for specifying a symbol including an effective symbol part with the same period as the effective symbol part specified by another set of radio parameters and a guard interval part with a different period from the guard interval part specified by the other set of radio parameters. The apparatus further includes a second deriving unit deriving a set of radio parameters so that an occupancy proportion of the guard interval part in a single symbol specified by another set of radio parameters is equal to an occupancy proportion of the guard interval part in a single symbol specified by the other set of radio parameters.Type: GrantFiled: October 27, 2010Date of Patent: August 2, 2011Assignee: NTT Docomo, Inc.Inventors: Mamoru Sawahashi, Kenichi Higuchi, Hiroyuki Atarashi, Motohiro Tanno, Yoshihisa Kishiyama, Yoshiaki Ofuji