Patents by Inventor Teruo Kawamura
Teruo Kawamura 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: 20110007778Abstract: Multiple reference signal transmission bandwidths are defined for system frequency bands and hierarchical reference signal bandwidths are defined for each reference signal transmission bandwidth such that a reference signal bandwidth lower than a highest-order reference signal bandwidth is a division of a higher-order reference signal bandwidth.Type: ApplicationFiled: June 22, 2009Publication date: January 13, 2011Applicant: NTT DOCOMO, INC.Inventors: Yoshihisa Kishiyama, Teruo Kawamura, Mamoru Sawahashi
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Publication number: 20100309857Abstract: A user device transmitting at least an uplink control channel using a single carrier scheme includes a channel quality indicator generating unit configured to generate a channel quality indicator indicating a downlink radio propagation condition; and a transmitting unit configured to transmit the uplink control channel including the channel quality indicator using a dedicated frequency band when no radio resource is allocated for transmission of an uplink data channel. The transmitting unit is configured to transmit a predetermined number of unit blocks in each slot period. If a system bandwidth is greater than a predetermined value, a set of factors used to multiply some of the unit blocks belonging to the same slot and containing the same information represents an orthogonal sequence; and a predetermined number of symbol elements constituting each of the some of the unit blocks represent at least a part of the channel quality indicator.Type: ApplicationFiled: October 27, 2008Publication date: December 9, 2010Applicant: NTT DOCOMO, INC.Inventors: Teruo Kawamura, Yoshihisa Kishiyama, Kenichi Higuchi, Mamoru Sawahashi
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Patent number: 7844299Abstract: A base station configured to communicate with a mobile station includes a controlling-information transmitting unit and a receiving unit. The controlling-information transmitting unit is configured to transmit to the mobile station as a set of controlling information, an information set indicating an environment of a cell which is resided by the mobile station, or an information set indicating power of interference from surrounding cells, or an information set indicating a condition of propagation channel. The receiving unit is configured to receive a signal transmitted from the mobile station, based on said set of controlling information, via a variably-controlling process of a spreading factor and a number of chip repetitions.Type: GrantFiled: May 6, 2008Date of Patent: November 30, 2010Assignee: NTT DoCoMo, Inc.Inventors: Hiroyuki Atarashi, Mamoru Sawahashi, Teruo Kawamura
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Publication number: 20100290544Abstract: A single carrier scheme is used in an uplink in the mobile communication system. A base station used in the mobile communication system includes: means configured to perform communication with a mobile station that uses the whole or a part of a system frequency band; storage means configured to store correspondence relationship between radio parameters including a bandwidth, a modulation scheme and a channel coding rate of the uplink and filter parameters including at least a roll-off factor of a band limitation filter; and determination means configured to determine radio parameters and filter parameters for each mobile station based on the correspondence relationship according to channel state of the uplink. The radio parameters and the filter parameters determined in the determination means are reported to the mobile station.Type: ApplicationFiled: March 19, 2007Publication date: November 18, 2010Applicant: NTT DOCOMO, INC.Inventors: Teruo Kawamura, Yoshihisa Kishiyama, Kenichi Higuchi, Mamoru Sawahashi
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Publication number: 20100246512Abstract: A mobile station includes a channel quality estimation unit configured to estimate downlink channel quality based on a reference signal from a base station and to output the estimated downlink channel quality as channel estimation information; an acknowledgement information determining unit configured to determine whether a downlink data channel from the base station is correctly received and to output the determination result as acknowledgement information; and an acknowledgement information prioritizing unit configured to cause the acknowledgement information to be preferentially transmitted to the base station if transmission timings of the channel estimation information and the acknowledgement information coincide.Type: ApplicationFiled: September 26, 2008Publication date: September 30, 2010Applicant: NTT DOCOMO, INC.Inventors: Teruo Kawamura, Yoshihisa Kishiyama, Kenichi Higuchi, Mamoru Sawahashi
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Publication number: 20100189058Abstract: A base station apparatus is disclosed which communicates with a user apparatus which transmits an uplink signal using a single-carrier scheme. The base station includes a sequence-identifier determining unit which performs scheduling to allocate a frequency based on an uplink channel reception state of the user apparatus, and which determines a second sequence identifier for use by the user apparatus based on a first sequence identifier in a length of a reference signal sequence for transmitting in a maximum bandwidth in which the user apparatus can transmit, and a frequency bandwidth allocated to the user apparatus.Type: ApplicationFiled: June 17, 2008Publication date: July 29, 2010Applicant: NTT DOCOMO, INC.Inventors: Teruo Kawamura, Kenichi Higuchi, Mamoru Sawahashi
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Publication number: 20100118825Abstract: A disclosed radio base station is used in a mobile communication system employing a single carrier scheme for uplink and includes a scheduler configured to allocate radio resources such that a first control channel accompanying an uplink data channel is transmitted using the same frequency band allocated to the uplink data channel and a second control channel, which is to be transmitted regardless of presence or absence of the uplink data channel, is transmitted using a dedicated frequency band reserved for the second control channel if no frequency band is allocated to the uplink data channel; and a reporting unit configured to report scheduling information indicating the allocation results to a user device. The scheduler is configured not to allocate the radio resources to the uplink data channel of the user device in a unit transmission period reserved for transmission of the second control channel of the user device.Type: ApplicationFiled: August 13, 2007Publication date: May 13, 2010Applicant: NTT DOCOMO, INC.Inventors: Teruo Kawamura, Yoshihisa Kishiyama, Kenichi Higuchi, Mamoru Sawahashi
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Publication number: 20100118773Abstract: A disclosed user device generates an uplink control channel including at least one of acknowledgement information and a channel quality indicator regarding downlink and transmits the uplink control channel via a dedicated frequency band when no resource is allocated for transmission of an uplink data channel. The uplink control channel includes multiple unit blocks constituting a subframe and each of the unit blocks includes a sequence generated by multiplying all chips of an orthogonal code sequence assigned to the user device by the same factor.Type: ApplicationFiled: March 13, 2008Publication date: May 13, 2010Applicant: NTT DOCOMO, INC.Inventors: Teruo Kawamura, Yoshihisa Kishiyama, Kenichi Higuchi, Mamoru Sawahashi
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Publication number: 20100111044Abstract: A communication system is provided with a plurality of mobile stations and a base station. A mobile station makes a pilot channel composed of a Cassak code correspond to a signal having a plurality of frequency components in a predetermined band disposed in parallel with each other in a constant distance. A mobile station transmits a transmission signal including such a signal in accordance with a scheduling signal. The mobile station also makes its own transmission signal correspond to transmission signals of other mobile stations using different bands from a band of that own transmission signal in order for the former to be orthogonal with the latter on a frequency axis. A base station calculates a difference between a receiving signal and a replica of the pilot channel to infer a channel. The base station decodes the receiving signal by using a channel inference result.Type: ApplicationFiled: January 10, 2007Publication date: May 6, 2010Applicant: NTT DOCOMO, INC.Inventors: Teruo Kawamura, Yoshihisa Kishiyama, Kenichi Higuchi, Mamoru Sawahashi
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BASE STATION APPARATUS, MOBILE STATION, RADIO COMMUNICATION SYSTEM, AND COMMUNICATION CONTROL METHOD
Publication number: 20100091708Abstract: In a radio communication system including a mobile station and a base station apparatus for communicating with the mobile station according to a SC-FDMA scheme in uplink, the mobile station includes a transmitting unit configured to transmit at least one of a first signal and a second signal; and a Sounding RS transmitting unit configured to determine a transmission band for a Sounding Reference Signal (Sounding RS) based on mapping information of at least one of the first signal and the second signal.Type: ApplicationFiled: February 12, 2008Publication date: April 15, 2010Applicant: NTT DOCOMO, INC.Inventors: Daisuke Nishikawa, Hiroyuki Ishii, Teruo Kawamura, Kenichi Higuchi -
Publication number: 20100046480Abstract: A user apparatus generates an uplink control channel including at least one of acknowledgement information and channel condition information on an downlink, and transmits the uplink control channel in a predefined dedicated band if no resource is assigned to transmit an uplink data channel. The uplink control channel includes multiple unit block sequences resulting from multiplication of the same factor with all chips of a CAZAC code sequence for the user apparatus.Type: ApplicationFiled: October 1, 2007Publication date: February 25, 2010Applicant: NTT DOCOMO, INC.Inventors: Teruo Kawamura, Kenichi Higuchi, Mamoru Sawahashi
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Patent number: 7647060Abstract: A wireless communications system includes a base station and multiple mobile stations performing wireless communication with the base station in a DS-CDMA scheme. Each of the mobile stations has a transmission unit configured to transmit a timing difference detection packet to the base station, prior to transmitting packet data. The base station has a transmission timing control unit configured to detect a difference in signal receive timing from the mobile stations based on the timing difference detection packet, produce transmission timing control information for each of the mobile stations based on the detection result, and supply the transmission timing control information to each of the mobile stations to cause the mobile stations to adjust the transmission timing of the packet data.Type: GrantFiled: October 7, 2004Date of Patent: January 12, 2010Assignee: NTT DoCoMo, Inc.Inventors: Teruo Kawamura, Hiroyuki Atarashi, Mamoru Sawahashi
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Publication number: 20090290627Abstract: The present invention relates to a code evaluation method comprising the steps of computing an auto-correlation function from a generated code; computing an evaluation reference value for determining quality of the generated code based on the auto-correlation function and a weighting factor determined depending on the evaluation reference value; and determining the quality of the generated code based on the evaluation reference value.Type: ApplicationFiled: March 19, 2007Publication date: November 26, 2009Applicant: NTT DoCoMo, Inc.Inventors: Kenichi Higuchi, Teruo Kawamura, Mamoru Sawahashi, Xiaoming Dai, Yong Bai, Lan Chen
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Publication number: 20090220017Abstract: A transmission apparatus used in a mobile communication system adopting a single carrier scheme in an uplink includes: multiplexing means configured to multiplex a pilot channel, a control channel, and a data channel; and transmission means configured to transmit a transmission symbol including at least the pilot channel and the control channel using the uplink. A first pilot channel used for a reception apparatus to measure channel state of the uplink is transmitted using a frequency band over a plurality of resource blocks. A second pilot channel for compensating for a channel transmitted by the uplink is transmitted by a resource block assigned to the transmission apparatus. Control channels of the transmission apparatus and the apparatus other than the transmission apparatus are orthogonalized with each other by a FDM scheme.Type: ApplicationFiled: April 19, 2007Publication date: September 3, 2009Applicant: NTT DOCOMO, INC.Inventors: Teruo Kawamura, Yoshihisa Kishiyama, Kenichi Higuchi, Mamoru Sawahashi
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Publication number: 20090207803Abstract: A disclosed base station in a mobile communications system which uses a single-carrier technique for uplink includes a classifying unit which classifies, for each of multiple user apparatuses according to a path loss between the respective user apparatus and the base station, the multiple user apparatuses into two or more groups; and a scheduler which plans allocating of uplink resources to the user apparatuses. Uplink signals of each user apparatus that have multiple frequency components lined up in equal frequency intervals are multiplexed using a distributed frequency division multiplexing technique such that they are made mutually orthogonal on a frequency axis, the scheduler plans the resource allocating such that the user apparatuses belonging to different groups utilize different group bands or different time slots, and the group bands are specified by dividing a system band into groups.Type: ApplicationFiled: June 13, 2007Publication date: August 20, 2009Applicant: NTT DoCoMo, Inc.Inventors: Teruo Kawamura, Yoshiaki Ofuji, Yoshihisa Kishiyama, Kenichi Higuchi, Mamoru Sawahashi, Seizo Onoe
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Publication number: 20090196249Abstract: A base station used in a mobile communication system employing a single carrier scheme for uplink transmission is disclosed. The base station includes a scheduler configured to allocate one or more uplink resource blocks to a user device according to uplink channel conditions of the user device; and a reporting unit configured to report scheduling information indicating the allocation result to the user device. An uplink control channel of the user device is mapped to a resource block in a transmission frame including multiple resource blocks according to a hopping pattern based on the scheduling information; and the uplink control channel is mapped to a resource block according to the same hopping pattern regardless of whether the uplink control channel is associated with a user data channel.Type: ApplicationFiled: June 13, 2007Publication date: August 6, 2009Applicant: NTT DOCOMO, INC.Inventors: Teruo Kawamura, Yoshihisa Kishiyama, Kenichi Higuchi, Mamoru Sawahashi
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Publication number: 20090185602Abstract: A transmitter includes: spread code multiplying means that multiplies a symbol indicating a reference signal by spread code to generate a chip sequence after spreading; chip pattern generation means that generates a chip pattern by performing chip repetition a predetermined repetition number of times on the chip sequence after spreading; and multiplying means that multiplies a signal having the chip pattern by a phase specific to the transmitter.Type: ApplicationFiled: March 24, 2006Publication date: July 23, 2009Applicant: NTT DOCOMO, INC.Inventors: Hiroyuki Atarashi, Teruo Kawamura, Yoshikazu Goto, Mamoru Sawahashi
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Publication number: 20090135791Abstract: A base station includes: a first reception timing detecting unit configured to detect a reception timing of a packet received from a first mobile station of multiple mobile stations which is situated in a first sector; a second reception timing detecting unit configured to detect a reception timing of a packet received from a second mobile station of the multiple mobile stations which is situated in a second sector; a transmission timing determining unit configured to determine transmission timings of signals transmitted from the first mobile station and the second mobile station based on the reception timings detected by the first reception timing detecting unit and the second reception timing detecting unit; a control information generating unit configured to generate transmission timing control information for the first mobile station and the second mobile station based on the transmission timings; and a radio resource allocating unit configured to allocate orthogonal radio resources to the first mobile stType: ApplicationFiled: August 21, 2006Publication date: May 28, 2009Applicant: NTT DOCOMO, INC.Inventors: Teruo Kawamura, Yoshihisa Kishiyama, Kenichi Higuchi, Mamoru Sawahashi
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Publication number: 20080225820Abstract: A mobile station for wirelessly transmitting to a base station by DS-CDMA a signal which is spread by multiplying a spreading code includes a high-precision transmission timing control unit configured to control transmitting timings of transmitting signals so that a time difference at the base station among timings of receiving from a plurality of mobile stations approaches zero.Type: ApplicationFiled: May 6, 2008Publication date: September 18, 2008Applicant: NTT DoCoMo, Inc.Inventors: Hiroyuki Atarashi, Mamoru Sawahashi, Teruo Kawamura
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Publication number: 20080214222Abstract: A base station configured to communicate with a mobile station includes a controlling-information transmitting unit and a receiving unit. The controlling-information transmitting unit is configured to transmit to the mobile station as a set of controlling information, an information set indicating an environment of a cell which is resided by the mobile station, or an information set indicating power of interference from surrounding cells, or an information set indicating a condition of propagation channel. The receiving unit is configured to receive a signal transmitted from the mobile station, based on said set of controlling information, via a variably-controlling process of a spreading factor and a number of chip repetitions.Type: ApplicationFiled: May 6, 2008Publication date: September 4, 2008Applicant: NTT DoCoMo, Inc.Inventors: Hiroyuki Atarashi, Mamoru Sawahashi, Teruo Kawamura