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).

  • Patent number: 8797946
    Abstract: 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: Grant
    Filed: March 13, 2008
    Date of Patent: August 5, 2014
    Assignee: NTT DoCoMo, Inc.
    Inventors: Teruo Kawamura, Yoshihisa Kishiyama, Kenichi Higuchi, Mamoru Sawahashi
  • Patent number: 8797990
    Abstract: To efficiently use radio resources used in transmission of SRS, a base station apparatus (eNode B) transmits a scheduling grant including an instruction for transmission of a Sounding Reference Signal (SRS), and a mobile station apparatus (UE) transmits the SRS in response to the scheduling grant. The SRS is transmitted in the same subframe, another subframe or a previous subframe by the predetermined number of subframes as, immediately before, or before a subframe of a PUSCH (Physical Uplink Shared Channel) that the scheduling grant instructs to transmit.
    Type: Grant
    Filed: February 15, 2011
    Date of Patent: August 5, 2014
    Assignee: NTT DoCoMo, Inc.
    Inventors: Yoshihisa Kishiyama, Teruo Kawamura, Daisuke Nishikawa
  • Patent number: 8780851
    Abstract: 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: Grant
    Filed: January 23, 2013
    Date of Patent: July 15, 2014
    Assignee: NTT DoCoMo, Inc.
    Inventors: Daisuke Nishikawa, Hiroyuki Ishii, Teruo Kawamura, Kenichi Higuchi
  • Patent number: 8767664
    Abstract: Provided are a mobile terminal apparatus, a radio base station apparatus and a radio communication method, capable of saving PHICH resources enough and realizing effective retransmission control of uplink SU-MIMO. The radio communication method of the present invention is characterized in that a radio base station apparatus receives signals of plural codewords, when there is an error in each of the codewords, generates a one-bit negative response physical HARQ indicator channel signal and transmits the physical HARQ indicator channel signal, and a mobile terminal apparatus receives the physical HARQ indicator channel signal and transmits retransmission signals of all the codewords to the radio base station apparatus based on the negative response physical HARQ indicator channel signal.
    Type: Grant
    Filed: February 9, 2011
    Date of Patent: July 1, 2014
    Assignee: NTT DoCoMo, Inc.
    Inventors: Hidekazu Taoka, Nobuhiko Miki, Teruo Kawamura, Yuichi Kakishima
  • Patent number: 8711815
    Abstract: To provide a mobile terminal apparatus, radio base station apparatus and radio communication method capable of supporting user multiplexing methods for enabling more users to be efficiently multiplexed on an uplink shared channel, the mobile terminal apparatus performs spreading processing for multiplying a data signal by a code varying for each user, and transmits the spreading-processed data signal to the radio base station apparatus on the uplink shared channel, and the radio base station apparatus receives the data signal, and user-separates a reception signal in which is mixed a plurality of users multiplied by spreading codes varying for each user into desired user signals to be data signals for each user.
    Type: Grant
    Filed: August 2, 2010
    Date of Patent: April 29, 2014
    Assignee: NTT DoCoMo, Inc.
    Inventors: Teruo Kawamura, Mamoru Sawahashi
  • Patent number: 8665926
    Abstract: In a closed-loop TPC for a channel using a wireless resource, to which frequency hopping is applied, a high quality reception is achieved for all RBs without applying another technique to each RB. This transmission power control method, in a mobile communications system that transmits signals by frequency hopping in a plurality of resource blocks, includes a transmission power control method that transmission-power controls a channel in a closed loop using a wireless resource to which frequency hopping is applied, measures a reception channel quality of received signals for each resource block (RB1 and RB2), and transmits a TPC command-bit via a downlink so that the reception quality that is independently measured at each resource block among the resource blocks is made equal to a target reception quality.
    Type: Grant
    Filed: June 26, 2009
    Date of Patent: March 4, 2014
    Assignee: NTT Docomo, Inc.
    Inventors: Teruo Kawamura, Yoshihisa Kishiyama, Kenichi Higuchi, Mamoru Sawahashi
  • Publication number: 20140016599
    Abstract: A base station apparatus includes a communication unit configured to communicate with base stations of a plurality of adjacent cells; a management unit configured to manage frequency bands for use in the adjacent cells; and a determination unit configured to determine instruction contents according to status of use of the frequency bands. The instruction contents are reported to all or a part of the adjacent cells via the communication unit. The instruction contents specify: a type of a pilot channel transmitted by a user residing in an adjacent cell; whether pilot channels of each user are code-division multiplexed or not; and whether pilot channels of each user are frequency-division multiplexed or not, and the like.
    Type: Application
    Filed: September 4, 2013
    Publication date: January 16, 2014
    Applicant: NTT DOCOMO, INC.
    Inventors: Teruo Kawamura, Yoshihisa Kishiyama, Mamoru Sawahashi
  • Patent number: 8630226
    Abstract: A disclosed communication system includes multiple mobile stations and a base station. The mobile station maps a pilot channel comprising a CAZAC code to a signal including multiple frequency components arranged at regular intervals in a given frequency band, and transmits a transmission signal including the signal according to scheduling information. The mobile station performs the mapping such that its transmission signal and transmission signals of other mobile stations using different frequency bands become orthogonal to each other on a frequency axis. The base station calculates the correlation between a received signal and a pilot channel replica, performs channel estimation, and demodulates the received signal based on the result of channel estimation. The base station generates the pilot channel replica by mapping a pilot channel comprising a CAZAC code to a signal including multiple frequency components arranged at regular intervals in a given frequency band.
    Type: Grant
    Filed: January 10, 2007
    Date of Patent: January 14, 2014
    Assignee: NTT DoCoMo, Inc.
    Inventors: Teruo Kawamura, Yoshihisa Kishiyama, Kenichi Higuchi, Mamoru Sawahashi
  • Publication number: 20140003398
    Abstract: 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: Application
    Filed: August 30, 2013
    Publication date: January 2, 2014
    Applicant: NTT DOCOMO, INC.
    Inventors: Teruo Kawamura, Kenichi Higuchi, Mamoru Sawahashi
  • Patent number: 8615046
    Abstract: A transmission apparatus for transmitting an uplink control signal by using a predetermined number of basic frequency blocks in a plurality of basic frequency blocks, wherein a system band is divided into a plurality of bands by a basic frequency block having a predetermined bandwidth, includes: a mapping unit configured to map control information to subcarriers in a basic frequency block in a given subframe; an inverse Fourier transform unit configured to perform inverse Fourier transform on a signal to which the control information is mapped; and a radio transmission unit configured to transmit a transmission signal, to a receiving apparatus by radio, including a signal on which inverse Fourier transform has been performed. In a subframe subsequent to the given subframe, the mapping unit maps the control information to subcarriers in a basic frequency block of a band different from a band of the basic frequency block in the given subframe.
    Type: Grant
    Filed: August 3, 2009
    Date of Patent: December 24, 2013
    Assignee: NTT DoCoMo, Inc.
    Inventors: Nobuhiko Miki, Teruo Kawamura, Kenichi Higuchi, Mamoru Sawahashi
  • Patent number: 8594117
    Abstract: A 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: Grant
    Filed: June 13, 2007
    Date of Patent: November 26, 2013
    Assignee: NTT DoCoMo, Inc.
    Inventors: Teruo Kawamura, Yoshiaki Ofuji, Yoshihisa Kishiyama, Kenichi Higuchi, Mamoru Sawahashi, Seizo Onoe
  • Patent number: 8565166
    Abstract: 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: Grant
    Filed: October 1, 2007
    Date of Patent: October 22, 2013
    Assignee: NTT DoCoMo, Inc.
    Inventors: Teruo Kawamura, Kenichi Higuchi, Mamoru Sawahashi
  • Patent number: 8559297
    Abstract: A user apparatus to which radio access schemes of a single-carrier scheme and a multicarrier scheme are applied includes: a radio access scheme setting unit configured to set a radio access scheme; a discrete Fourier transform unit configured to perform discrete Fourier transform on a modulated symbol sequence when the radio access scheme is the single-carrier scheme; a serial parallel conversion unit configured to perform serial parallel conversion on the modulated symbol sequence when the radio access scheme is the multicarrier scheme; a frequency domain signal generation unit configured to assign radio resources to the modulated symbol sequence on which discrete Fourier transform has been performed or to the demodulated symbol sequence on which serial parallel conversion has been performed so as to generate a signal in the frequency domain; a waveform shaping filter configured to perform waveform shaping on the signal in the frequency domain; a transmission signal generation unit configured to perform inve
    Type: Grant
    Filed: March 25, 2009
    Date of Patent: October 15, 2013
    Assignee: NTT DoCoMo, Inc.
    Inventors: Teruo Kawamura, Yoshihisa Kishiyama, Kenichi Higuchi, Mamoru Sawahashi
  • Patent number: 8526511
    Abstract: 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: Grant
    Filed: March 19, 2007
    Date of Patent: September 3, 2013
    Assignee: NTT DoCoMo, Inc.
    Inventors: Teruo Kawamura, Yoshihisa Kishiyama, Kenichi Higuchi, Mamoru Sawahashi
  • Patent number: 8520757
    Abstract: A communications apparatus includes a receiving unit which receives a data channel for each predetermined transmission period; a determining unit which determines, for each data channel, acknowledgement information which indicates an acknowledgement or a non-acknowledgement; a generating unit which generates a control channel including the acknowledgement information; and a transmitting unit which transmits the control channel. For first and second data channels received during at least successive first and second transmission periods, the first and second acknowledgement information is provided. The second control channel which includes both the first and the second acknowledgement information which includes both the first and the second acknowledgement information is transmitted after a first control channel which includes the first acknowledgement information.
    Type: Grant
    Filed: June 22, 2009
    Date of Patent: August 27, 2013
    Assignee: NTT DoCoMo, Inc.
    Inventors: Yoshihisa Kishiyama, Teruo Kawamura, Nobuhiko Miki, Mamoru Sawahashi
  • Patent number: 8498347
    Abstract: 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: Grant
    Filed: April 19, 2007
    Date of Patent: July 30, 2013
    Assignee: NTT DoCoMo, Inc.
    Inventors: Teruo Kawamura, Yoshihisa Kishiyama, Kenichi Higuchi, Mamoru Sawahashi
  • Patent number: 8498351
    Abstract: 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: Grant
    Filed: October 12, 2011
    Date of Patent: July 30, 2013
    Assignee: NTT DoCoMo, Inc.
    Inventors: Teruo Kawamura, Yoshihisa Kishiyama, Kenichi Higuchi, Mamoru Sawahashi
  • Publication number: 20130176987
    Abstract: The present invention aims to provide a transmitter, a receiver and a radio communication method capable of preventing any increase in overhead due to insertion of reference signals without deteriorating the channel estimation accuracy. The radio communication method is provided for mapping reference signals to radio resources of a plurality of layers and transmitting the reference signals, having the steps of: generating the reference signals; oversampling the reference signals; and mapping the oversampled reference signals to resource elements of the layers respectively. Reference signals to be mapped to different layers are subjected to frequency division multiplexing in resource elements of same time and frequency domains.
    Type: Application
    Filed: August 10, 2011
    Publication date: July 11, 2013
    Applicant: NTT DOCOMO, INC.
    Inventor: Teruo Kawamura
  • Publication number: 20130148599
    Abstract: 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: Application
    Filed: January 23, 2013
    Publication date: June 13, 2013
    Inventors: Daisuke Nishikawa, Hiroyuki Ishii, Teruo Kawamura, Kenichi Higuchi
  • Patent number: 8457055
    Abstract: 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: Grant
    Filed: August 13, 2007
    Date of Patent: June 4, 2013
    Assignee: NTT DoCoMo, Inc.
    Inventors: Teruo Kawamura, Yoshihisa Kishiyama, Kenichi Higuchi, Mamoru Sawahashi