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: 9491775
    Abstract: To improve the frequency diversity effect and enhance reception quality characteristics in a mobile terminal apparatus even when the system bandwidth is extended, provided are a base station apparatus which maps transmission data to each user to a single or plurality of group bands among group bands configured by dividing a system band into a plurality of bands, and transmits the mapped transmission data on downlink, and a mobile terminal apparatus which receives the transmission data mapped to the group bands and demaps the transmission data.
    Type: Grant
    Filed: January 6, 2010
    Date of Patent: November 8, 2016
    Assignee: NTT DOCOMO, INC.
    Inventors: Satoshi Nagata, Kazuaki Takeda, Nobuhiko Miki, Yoshihisa Kishiyama, Mamoru Sawahashi
  • Patent number: 9479313
    Abstract: A base station apparatus is used in a mobile communication system in which at least a shared data channel is transmitted by an orthogonal modulation scheme using an I-channel and a Q-channel. The base station apparatus includes a providing unit providing Acknowledgement/Non-Acknowledgement information indicating whether retransmission of a signal received in uplink is required; a mapping unit mapping a number of multiplexed users of the Acknowledgement/Non-Acknowledgement information to the I-channel or the Q-channel based on a predetermined mapping table; and a reporting unit reporting the Acknowledgement/Non-Acknowledgement information to the respective users. The mapping table indicates that, when the number of the multiplexed users is equal to or less than a predetermined number, the Acknowledgement/Non-Acknowledgement information is associated with the I-channel or the Q-channel, and otherwise, the Acknowledgement/Non-Acknowledgement information is associated with the I-channel and the Q-channel.
    Type: Grant
    Filed: September 19, 2013
    Date of Patent: October 25, 2016
    Assignee: NTT DOCOMO, INC.
    Inventors: Nobuhiko Miki, Mamoru Sawahashi, Kenichi Higuchi
  • Patent number: 9474079
    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: Grant
    Filed: April 9, 2013
    Date of Patent: October 18, 2016
    Assignee: NEC CORPORATION
    Inventors: Motohiro Tanno, Yoshihisa Kishiyama, Kenichi Higuchi, Mamoru Sawahashi, Toshifumi Sato
  • Patent number: 9391750
    Abstract: A transmission apparatus is provided with radio resource assignment means that assigns radio resources to each physical channel according to a type of the physical channel; and transmission means that transmits information to be transmitted by each physical channel using the assigned radio resources.
    Type: Grant
    Filed: March 20, 2006
    Date of Patent: July 12, 2016
    Assignee: NTT DOCOMO, INC.
    Inventors: Nobuhiko Miki, Motohiro Tanno, Kenichi Higuchi, Mamoru Sawahashi, Hiroyuki Atarashi
  • Patent number: 9370014
    Abstract: In a radio communication system, a downlink frequency band includes a plurality of frequency blocks including one or more carrier frequencies, and one or more frequency blocks are used for data transmission to a single user. A radio communication apparatus for use in the communication system has an evaluation unit evaluating the quality of a received signal for each frequency block and storing plurality of stored quality evaluations of the received signal, a comparison unit comparing the plural quality evaluations of the received signal, and a transmission unit transmitting a predetermined number of the quality evaluations of the received signal over an uplink control channel.
    Type: Grant
    Filed: May 9, 2013
    Date of Patent: June 14, 2016
    Assignee: NTT DOCOMO, INC.
    Inventors: Motohiro Tanno, Hiroyuki Atarashi, Kenichi Higuchi, Mamoru Sawahashi
  • Patent number: 9369996
    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: Grant
    Filed: April 15, 2013
    Date of Patent: June 14, 2016
    Assignee: NTT DOCOMO, INC.
    Inventors: Kenichi Higuchi, Mamoru Sawahashi
  • Patent number: 9313787
    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: Grant
    Filed: July 11, 2013
    Date of Patent: April 12, 2016
    Assignee: NTT DOCOMO, INC.
    Inventors: Nobuhiko Miki, Kenichi Higuchi, Mamoru Sawahashi
  • Patent number: 9281926
    Abstract: To provide a radio base station apparatus and radio communication method capable of performing radio communications using downlink reference signal structures suitable for antenna virtualization, a radio base station apparatus (200) has a plurality of transmission antennas, generates CRSs used in demodulation of at least downlink control information, CQI-RSs generated for each of the transmission antennas used in measurement of channel quality, and DM-RSs generated for each stream used in demodulation of downlink transmission data, and multiplexes the CRSs, CQI-RSs and DM-RSs into a same transmission time unit to transmit from each of the antennas.
    Type: Grant
    Filed: March 16, 2010
    Date of Patent: March 8, 2016
    Assignee: NTT DOCOMO, INC.
    Inventors: Yoshihisa Kishiyama, Hidekazu Taoka, Mamoru Sawahashi
  • Patent number: 9232447
    Abstract: To provide a radio base station apparatus and mobile terminal for enabling cell selection to be performed in a faster cell switching period in handover, the radio base station apparatus of the invention has a plurality of transmission/reception sections capable of being extended to remote sites, an FCS application determining section that determines whether to apply fast cell selection in handover based on information from the mobile terminal, and a multi-cell scheduling control section that controls transmission/non-transmission of the first and second transmission/reception sections when the FCS application determining section determines that FCS is applied.
    Type: Grant
    Filed: September 9, 2014
    Date of Patent: January 5, 2016
    Assignee: NTT DOCOMO, INC.
    Inventors: Yoshihisa Kishiyama, Motohiro Tanno, Mamoru Sawahashi
  • Patent number: 9185687
    Abstract: In a radio communication system defining a plurality of bandwidths, mobile terminals of kinds respectively corresponding to the plurality of bandwidths are accommodated in the system, and a minimum transmission bandwidth of the plurality of bandwidths is set as a transmission bandwidth of a downlink common channel. Or, every mobile terminal accommodated in the radio communication system is provided with a capability for processing a bandwidth equal to or greater than a predetermined value, and equal to or more than two transmission bandwidths that are equal to or less than a predetermined value are set as a transmission bandwidth of a downlink common channel. In the latter case, the mobile terminal identifies a bandwidth of a received downlink common channel.
    Type: Grant
    Filed: October 31, 2013
    Date of Patent: November 10, 2015
    Assignee: NTT DOCOMO, INC.
    Inventors: Kenichi Higuchi, Hiroyuki Atarashi, Mamoru Sawahashi
  • Patent number: 9167533
    Abstract: A base station apparatus for a mobile communication system is disclosed that includes a unit to receive an uplink reference signal transmitted from user equipment, a unit to provide transmission power control data indicating whether a transmission power value of the uplink reference signal to be transmitted later is to be changed, a unit to derive a first offset power value so that the uplink control signal is transmitted at a power value determined by adding the first offset power value to the transmission power value of the uplink reference signal, a unit to derive a second offset power value so that the uplink control signal is transmitted at a power value determined by adding the second offset power value to the transmission power value of the uplink reference signal, and a unit to report the data and values to the user equipment.
    Type: Grant
    Filed: December 26, 2007
    Date of Patent: October 20, 2015
    Assignee: NTT DOCOMO, INC.
    Inventors: Yoshihisa Kishiyama, Kenichi Higuchi, Mamoru Sawahashi
  • Patent number: 9144078
    Abstract: In a radio communication system, a downlink frequency band includes a plurality of frequency blocks including one or more carrier frequencies, and one or more frequency blocks are used for data transmission to a single user. A radio communication apparatus for use in the communication system has an evaluation unit evaluating the quality of a received signal for each frequency block and storing plurality of stored quality evaluations of the received signal, a comparison unit comparing the plural quality evaluations of the received signal, and a transmission unit transmitting a predetermined number of the quality evaluations of the received signal over an uplink control channel.
    Type: Grant
    Filed: March 20, 2006
    Date of Patent: September 22, 2015
    Assignee: NTT DOCOMO, INC.
    Inventors: Motohiro Tanno, Hiroyuki Atarashi, Kenichi Higuchi, Mamoru Sawahashi
  • Patent number: 9136996
    Abstract: A user device for a mobile communication system employing a multicarrier scheme is disclosed. The user device includes a control signal generating unit for generating a control signal. The user device also includes a transmitting unit for transmitting the control signal to a base station. The control signal sent by the user device is mapped to multiple frequency bands throughout a time period of a subframe but separated from each other in a frequency domain. Each of the frequency bands includes subcarriers used in orthogonal frequency division multiplexing.
    Type: Grant
    Filed: June 18, 2009
    Date of Patent: September 15, 2015
    Assignee: NTT DOCOMO, INC.
    Inventors: Teruo Kawamura, Yoshihisa Kishiyama, Nobuhiko Miki, Mamoru Sawahashi
  • Patent number: 9130699
    Abstract: A transmitting device for a mobile communication system employing a multicarrier scheme includes a mapping unit configured to map control information to subcarriers in a subframe; an inverse Fourier transform unit configured to inverse-Fourier-transform a signal of the mapped control information; and a transmitting unit configured to wirelessly transmit a transmission signal including the inverse-Fourier-transformed signal to a receiving device. The control information is mapped to control frequency bands that are discontinuous in the frequency domain and are provided across the subframe separately from frequency bands for a shared data channel. The mapping is performed such that the control information for the receiving device mapped to one of the control frequency bands is transmitted at the same time as the control information or the shared data channel for the receiving device mapped to a different frequency band.
    Type: Grant
    Filed: February 27, 2009
    Date of Patent: September 8, 2015
    Assignee: NTT DOCOMO, INC.
    Inventors: Teruo Kawamura, Yoshihisa Kishiyama, Mamoru Sawahashi
  • Patent number: 9130616
    Abstract: A user apparatus in a multi input multi output (MIMO) mobile communications system using pre-encoding is disclosed. The user apparatus includes a PMI generator which generates a pre-encoding matrix indicator (PMI) which indicates a pre-encoding matrix to be used by a base station; a transmitter which feeds back the PMI to the base station; and a receiver which receives a signal from the base station, wherein the signal received at the receiver includes information on whether it is according to PMI information fed back from the user apparatus after a predetermined elapsed time from a timing at which the PMI information is fed back from the user apparatus.
    Type: Grant
    Filed: December 26, 2008
    Date of Patent: September 8, 2015
    Assignee: NTT DOCOMO, INC.
    Inventors: Hidekazu Taoka, Nobuhiko Miki, Kenichi Higuchi, Mamoru Sawahashi
  • Patent number: 9112696
    Abstract: A radio communication apparatus includes a scheduling unit configured to determine a resource block based on an allocation pattern of resource blocks, where frames in which multiple resource blocks are arranged in a frequency direction are repeatedly formed in a time direction, the allocation pattern using a frame number as a variable. The radio communication apparatus also includes a transmitting unit configured to transmit a packet according to the resource block determined by the scheduling unit.
    Type: Grant
    Filed: September 5, 2012
    Date of Patent: August 18, 2015
    Assignee: NTT DOCOMO, INC.
    Inventors: Nobuhiko Miki, Kenichi Higuchi, Mamoru Sawahashi
  • Patent number: 9094155
    Abstract: A disclosed transmission apparatus includes a multiplexing portion that multiplexes a common pilot channel, a shared control channel, and a shared data channel; a symbol generation portion that performs an inverse Fourier transformation on the multiplexed signal so as to generate a symbol; and a transmission portion that transmits the generated symbol. The multiplexing portion multiplexes the shared control channel including control information necessary for demodulation of the shared data channel including a payload and the common pilot channel to be used by plural users in a frequency direction, and the shared data channel in a time direction with respect to the common pilot channel and the shared control channel. Even when the number of symbols composing a transmission time interval (TTI) is reduced, transmission efficiency of channels excluding the common pilot channel can be maintained by reducing insertion intervals of the common pilot channel accordingly.
    Type: Grant
    Filed: May 22, 2012
    Date of Patent: July 28, 2015
    Assignee: NTT DOCOMO, INC.
    Inventors: Yoshihisa Kishiyama, Kenichi Higuchi, Mamoru Sawahashi
  • Patent number: 9088985
    Abstract: A base station includes a receiving unit configured to receive a UE capability regarding a bandwidth from a mobile station; and a specifying unit configured to specify, among plural basic frequency blocks included in a system band, one or more basic frequency blocks to be used by the mobile station based on the UE capability.
    Type: Grant
    Filed: March 27, 2009
    Date of Patent: July 21, 2015
    Assignee: NTT DOCOMO, INC.
    Inventors: Yoshihisa Kishiyama, Motohiro Tanno, Nobuhiko Miki, Hidekazu Taoka, Kenichi Higuchi, Mamoru Sawahashi
  • Patent number: 9036543
    Abstract: A mobile terminal apparatus and radio base station apparatus supporting each of a plurality of mobile communication systems when the plurality of mobile communication systems coexists is disclosed, wherein the mobile terminal apparatus is a mobile terminal apparatus in a radio communication system for performing transmission and reception in uplink and downlink, each assigned to a relatively wide system band obtained by aggregating a plurality of component carriers, each of which is a relatively narrow system band, and has coding and data modulation sections that perform coding and data modulation on uplink control signals including report information of individual component carriers assigned to downlink, and mapping sections that map the control signals subjected to coding and data modulation to uplink communication channels.
    Type: Grant
    Filed: September 18, 2009
    Date of Patent: May 19, 2015
    Assignee: NTT DOCOMO, INC.
    Inventors: Yoshihisa Kishiyama, Motohiro Tanno, Mamoru Sawahashi
  • Patent number: 9019979
    Abstract: To provide a radio base station apparatus and mobile terminal supporting each of a plurality of mobile communication systems when the plurality of mobile communication systems coexists, the radio base station apparatus assigns a modulated signal of a control signal to at least one frequency band with the system band of the LTE system as a unit on a predetermined data block basis (CCE basis) according to a predetermined rule, and when data blocks are assigned according to the rule as shown in FIG. 4(a), the mobile terminal demodulates CCEs of the same number in respective frequency bands at a time and thereby determines whether or not the signal is the control signal to the mobile terminal. Meanwhile, when data blocks are assigned according to the rules as shown in FIGS. 4(b) and 4(c), the mobile terminal demodulates a specific CCE block range in each frequency band, and thereby determines whether or not the signal is the control signal to the mobile terminal.
    Type: Grant
    Filed: July 7, 2009
    Date of Patent: April 28, 2015
    Assignee: NTT DOCOMO, INC.
    Inventors: Nobuhiko Miki, Yoshihisa Kishiyama, Mamoru Sawahashi