Patents by Inventor Mamoru Sawahashi

Mamoru Sawahashi 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: 8605663
    Abstract: A base station for transmitting a radio frame where an L1/L2 control channel is multiplexed into a portion of a subframe to transmit data on a shared data channel includes a broadcast channel generating unit configured to generate a broadcast channel; an L1/L2 control channel generating unit configured to generate the L1/L2 control channel corresponding to the broadcast channel, which includes at least one broadcast channel control information from the group consisting of: an update flag indicating whether information on the broadcast channel is modified, broadcast channel allocation information, and L3 control information for the broadcast channel; and a multiplexing unit configured to multiplex the broadcast channel, the shared data channel, and the L1/L2 control channel into the subframe.
    Type: Grant
    Filed: June 13, 2007
    Date of Patent: December 10, 2013
    Assignee: NTT DoCoMo, Inc.
    Inventors: Motohiro Tanno, Kenichi Higuchi, Mamoru Sawahashi, Minami Ishii
  • Patent number: 8599766
    Abstract: A transmission device according to an embodiment of the present invention includes a random access channel generation portion that generates a random access channel; an assignment portion that performs one of a continuous frequency assignment and a discontinuous comb-shaped frequency assignment for each user; and a transmission portion that transmits the random access channel with variable multi-bandwidth in accordance with the assignment, in a frequency band assigned to a contention-based channel.
    Type: Grant
    Filed: January 10, 2007
    Date of Patent: December 3, 2013
    Assignee: NTT DoCoMo, Inc.
    Inventors: Yoshihisa Kishiyama, 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
  • Publication number: 20130301576
    Abstract: A communication terminal in a multi-carrier system using a frequency bandwidth including a plurality of resource blocks, each of the resource blocks including one or more sub-carriers. The communication terminal includes a receiving unit configured to receive a signal in which a control channel is multiplexed into a single radio frame based on a number of control channels allocated into the single radio frame to use a lower coding rate by repeating transmitting without changing encoding method in which a channel other than the control channel is multiplexed in accordance with scheduling information for allocating one or more of the plurality of resource blocks to the communication terminal and a processing unit configured to perform a process on the signal received by the receiving unit.
    Type: Application
    Filed: July 11, 2013
    Publication date: November 14, 2013
    Inventors: Nobuhiko Miki, Kenichi Higuchi, Mamoru Sawahashi
  • Patent number: 8570961
    Abstract: A disclosed communication control method includes determining a number of bits for transmitting downlink shared data channel information based on one or both of a number of users and a traffic amount and generating a signal for the downlink shared data channel information to be transmitted with the determined number of bits.
    Type: Grant
    Filed: August 13, 2008
    Date of Patent: October 29, 2013
    Assignee: NTT DoCoMo, Inc.
    Inventors: Nobuhiko Miki, Yoshihisa Kishiyama, Kenichi Higuchi, Mamoru Sawahashi
  • Patent number: 8570966
    Abstract: Provided is a base station comprising a multiplexer so constituted as to frequency-divide/multiplex a first channel for transmitting first data to be transmitted to a plurality of mobile stations, and a second channel for transmitting second data to be transmitted to one mobile station.
    Type: Grant
    Filed: April 16, 2009
    Date of Patent: October 29, 2013
    Assignee: NTT DoCoMo, Inc.
    Inventors: Akihito Morimoto, Yoshihisa Kishiyama, Nobuhiko Miki, Motohiro Tanno, Kenichi Higuchi, Mamoru Sawahashi
  • 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: 8560001
    Abstract: A base station apparatus includes a transmit diversity setting unit configured to set a transmit diversity mode to be applied to a user equipment terminal; a reception quality calculating unit configured to determine reception quality corresponding to the transmit diversity mode based on the transmit diversity mode set by the transmit diversity setting unit; a scheduling unit configured to determine a user equipment terminal to which a radio resource is to be allocated based on the reception quality determined by the reception quality calculating unit; and a notifying unit configured to notify the user equipment terminal to which the radio resource is allocated as determined by the scheduling unit of the transmit diversity mode to be applied.
    Type: Grant
    Filed: April 23, 2009
    Date of Patent: October 15, 2013
    Assignee: NTT DoCoMo, Inc.
    Inventors: Hiroyuki Kawai, Akihito Morimoto, Hidekazu Taoka, 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: 8553632
    Abstract: A base station apparatus is used in a region in which a first system and a second system co-exist. In the first system, mobile communication is conducted using a variable system bandwidth not more than a basic bandwidth. In the second system, mobile communication is conducted using a variable system bandwidth which is not more than a bandwidth of an advanced system band which is at least as wide as multiple of the basic bandwidths. The base station apparatus generates a control signal for the first system and a control signal for the second system, orthogonally multiplexes them, and includes the same in a downlink signal to transmit the downlink signal. The advanced system band is divided such that it includes multiple of areas (P, Q, R, S) of the basic bandwidth. The control signal for the first system is included in one of the areas (Q). The control signal for the second system is included in at least one of the areas (P, Q, R, S).
    Type: Grant
    Filed: March 17, 2009
    Date of Patent: October 8, 2013
    Assignee: NTT DoCoMo, Inc.
    Inventors: Nobuhiko Miki, Motohiro Tanno, Mamoru Sawahashi, Kenichi Higuchi, Yoshihisa Kishiyama
  • Patent number: 8548512
    Abstract: A base station for a mobile communication system includes a speed detecting unit configured to detect the moving speed of a user device based on a signal received from the user device and indicating the moving speed; and a determining unit configured to select, based on the moving speed detected by the speed detecting unit, a wideband channel quality indicator indicating reception quality of an entire system frequency band allocated to the mobile communication system, or a combination of the wideband channel quality indicator and one or more channel quality indicators of subbands in the system frequency band as channel quality information that needs to be reported from the user device to the base station.
    Type: Grant
    Filed: December 26, 2008
    Date of Patent: October 1, 2013
    Assignee: NTT DoCoMo, Inc.
    Inventors: Satoshi Nagata, Hidekazu Taoka, Yoshihisa Kishiyama, Kenichi Higuchi, Mamoru Sawahashi
  • Patent number: 8532049
    Abstract: A radio base station used in a mobile communication system is disclosed. The radio base station includes a scheduler configured to allocate one or more resource blocks, which are defined by a predetermined bandwidth and a predetermined transmission time interval, to a user device; and a reporting unit configured to report scheduling information indicating radio resource allocation to the user device. The scheduler is configured to generate the scheduling information such that downlink data channels and downlink control channels are transmitted using the transmission time interval as a transmission unit and uplink control channels are transmitted using an integral multiple of the transmission time interval as a transmission unit.
    Type: Grant
    Filed: August 17, 2007
    Date of Patent: September 10, 2013
    Assignee: NTT DoCoMo, Inc.
    Inventors: Kenichi Higuchi, Yoshihisa Kishiyama, 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
  • Publication number: 20130223260
    Abstract: The object is achieved by providing a base station apparatus for performing time and frequency scheduling in uplink packet access with: an interference amount measurement part configured to measure an uplink interference amount for each interference amount measurement unit which comprises a predetermined period and a predetermined number of frequency blocks; an interference amount determination part configured to determine whether the uplink interference amount satisfies a predetermined condition; and an overload indicator reporting part configured to report an overload indicator to a neighboring cell when the predetermined condition is satisfied.
    Type: Application
    Filed: April 9, 2013
    Publication date: August 29, 2013
    Applicant: NEC CORPORATION
    Inventors: Motohiro Tanno, Yoshihisa Kishiyama, Kenichi Higuchi, Mamoru Sawahashi, Toshifumi Sato
  • Publication number: 20130223415
    Abstract: A base station apparatus in a radio communication system where transmit diversity is applied in uplinks includes a reference signal measurement unit configured to measure a receive level of the reference signal, a switch pitch determination unit configured to determine the antenna switch pitch of transmitting the reference signal based on the receive level measured by the reference signal measurement unit, and a transmitting unit configured to transmit the antenna switch pitch determined by the switch pitch determination unit.
    Type: Application
    Filed: April 15, 2013
    Publication date: August 29, 2013
    Applicant: NTT DOCOMO, INC.
    Inventors: 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: 8520608
    Abstract: 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: Grant
    Filed: June 14, 2007
    Date of Patent: August 27, 2013
    Assignee: NTT DoCoMo, Inc.
    Inventors: Yoshiaki Ofuji, Kenichi Higuchi, Mamoru Sawahashi
  • Patent number: 8522100
    Abstract: A radio communication apparatus having a retransmission function includes a pattern storing unit configured to store a correspondence between resource blocks used for a transmission packet and resource blocks used for a retransmission packet; and a packet scheduling unit configured to arrange the retransmission packet based on the correspondence.
    Type: Grant
    Filed: January 15, 2007
    Date of Patent: August 27, 2013
    Assignee: NTT DoCoMo, Inc.
    Inventors: Nobuhiko Miki, Kenichi Higuchi, Mamoru Sawahashi
  • Patent number: 8503378
    Abstract: A disclosed base station in a multi-carrier system performs frequency scheduling in a frequency bandwidth including plural resource blocks each including one or more sub-carriers. The base station includes a frequency scheduler determining scheduling information for allocating one or more resource blocks to a communication terminal having good channel quality based on a channel quality indicator reported from plural of the communication terminals; a unit encoding and modulating a control channel transmitting the scheduling information; a multiplexing unit frequency-division multiplexing the control channel with a channel other than the control channel in accordance with the scheduling information; and a unit transmitting an output signal from the multiplexing unit in the multi-carrier system.
    Type: Grant
    Filed: June 14, 2007
    Date of Patent: August 6, 2013
    Assignee: NTT DoCoMo, Inc.
    Inventors: Nobuhiko Miki, 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