Patents by Inventor Junichiro Kawamoto

Junichiro Kawamoto 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: 8023933
    Abstract: A radio control method is arranged to use a mobile station 10, an active set 20 to perform radio communication with the mobile station 10, and a radio control apparatus 30 for controlling the radio communication between the mobile station 10 and the active set 20, and the radio control method has a determination step wherein in a situation where the mobile station 10, while performing radio communication through A-DPCH with the active set 20, performs radio communication through HS-PDSCH with one radio base station included in the active set 20, the radio control apparatus 30 makes a determination of maintenance to perform a process of maintaining the radio communication through the HS-PDSCH, on the occasion when the mobile station 10 gives a change command to change a configuration of the active set 20 so as to result in failure in maintenance of the radio communication through the HS-PDSCH.
    Type: Grant
    Filed: August 22, 2007
    Date of Patent: September 20, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Junichiro Kawamoto, Takahiro Hayashi, Hiroyuki Ishii, Akihito Hanaki, Yoshikazu Goto, Koji Furutani
  • Patent number: 8009621
    Abstract: The radio terminal 10 includes a communication unit 11 configured to transmit a happy bit to the base station. The base station 100 includes: a comparison unit 126 configured to compare a priority class assigned to a control target terminal with a priority class assigned to a comparison target terminal; a first determination unit 127 configured to determine whether a happy bit rate is lower than a predetermined threshold; and a scheduling unit 120a configured to transmit, to the control target terminal, transmission rate decrease data for decreasing the transmission rate, when the priority class assigned to the control target terminal is lower than the priority class assigned to the comparison target terminal and when the happy bit rate is lower than the predetermined threshold.
    Type: Grant
    Filed: October 2, 2008
    Date of Patent: August 30, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Junichiro Kawamoto, Akihito Hanaki, Takahiro Hayashi, Yoshikazu Goto, Yukiko Takagi
  • Patent number: 8005037
    Abstract: A communication control method for a mobile communication system having a plurality of mobile stations, a radio base station, and a radio control station comprises a measurement step, an evaluation step, and a control step. In the measurement step, a plurality of congestion parameters related to factors generating congestion is measured in a mobile communication system. In the evaluation step, the radio control station evaluates a congestion degree corresponding to each of the plurality of congestion parameters. In the control step, a communication setting between the radio base station and at least one of the plurality of mobile stations is controlled in accordance with a control instruction transmitted from the radio control station to the radio base station when at least one of the plurality of congestion degrees is a prescribed level or more.
    Type: Grant
    Filed: September 28, 2007
    Date of Patent: August 23, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Hiroyuki Ishii, Takahiro Hayashi, Akihito Hanaki, Junichiro Kawamoto, Yoshikazu Goto, Koji Furutani
  • Patent number: 7991360
    Abstract: A receiving apparatus, a receiving method, and a radio communications system are disclosed. The receiving apparatus is for receiving CDMA signals transmitted by M antennas and received by N antennas, where M and N are positive integers. The receiving apparatus includes a multipath receiving signal demodulating unit for primary demodulation of the CDMA signals received by the receiving antennas to obtain estimated transmission signals, and for obtaining signals in a multipath environment of each path of the receiving antennas based on the estimated results. Further, the receiving apparatus includes a multipath interference canceling unit for deducting signals of the paths other than a target path from the signals received by the receiving antennas to obtain multipath interference cancelled signals. Further, the receiving apparatus includes a demodulator for secondary demodulation of the multipath interference cancelled signals.
    Type: Grant
    Filed: March 4, 2005
    Date of Patent: August 2, 2011
    Assignees: NTT DoCoMo, Inc., NEC Corporation
    Inventors: Junichiro Kawamoto, Noriyuki Maeda, Kenichi Higuchi, Mamoru Sawahashi, Shousei Yoshida, Masayuki Kimata
  • Patent number: 7937087
    Abstract: A radio communication system includes: a serving cell (for example, cell A functional unit 120) configured to transmit, to a radio terminal 10, an AG for directly specifying an uplink user data transmission rate and an RG for relatively specifying the uplink user data transmission rate; and a non-serving cell (for example, cell B functional unit 130) configured to transmit the RG to the radio terminal without transmitting the AG. The non-serving cell includes an instruction unit 132 configured to instruct the serving cell to decrease the uplink user data transmission rate, when a reception power of uplink user data received from the radio terminal 10 exceeds a predetermined interference threshold.
    Type: Grant
    Filed: October 7, 2008
    Date of Patent: May 3, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Yoshikazu Goto, Akihito Hanaki, Takahiro Hayashi, Junichiro Kawamoto, Yukiko Takagi
  • Patent number: 7801550
    Abstract: A base station includes a first selecting unit that selects a reduction target terminal, a first calculating unit that calculates a reduction amount of assigned transmission rate assigned to the reduction target terminal, a second selecting unit that selects an increase target terminal, a second calculating unit that calculates an increase amount of the assigned transmission rate assigned to the increase target terminal, and a transmitting unit that transmits transmission rate control date to a radio terminal. The second selecting unit selects the increase target terminal and the second calculating unit calculates the increase amount when the reduction target terminal is not selected by the first selecting unit.
    Type: Grant
    Filed: February 4, 2009
    Date of Patent: September 21, 2010
    Assignee: NTT DoCoMo, Inc.
    Inventors: Takahiro Hayashi, Akihito Hanaki, Junichiro Kawamoto, Yoshikazu Goto, Yukiko Takagi
  • Publication number: 20100235710
    Abstract: A disclosed signal transmission method in a radio multiplex transmission system comprises the steps of: serial-to-parallel converting serial data to be transmitted into N (N: two or more) parallel data series; independently performing an error-correcting encoding process on the parallel signals of the N data series serial-to-parallel converted; parallel-to-serial converting the parallel signals encoded with error-correcting codes; performing an interleaving process on the parallel-to-serial converted signals; serial-to-parallel converting the interleaved signals into L (L: two or more) parallel data series and transmitting each of the L data series using L antennas; receiving the transmitted signals; separating the received signals into M (M: two or more) data series and parallel-to-serial converting the M data series; performing a deinterleaving process on the parallel-to-serial converted signals; serial-to-parallel converting the deinterleaved signals into N data series; independently performing an error-co
    Type: Application
    Filed: May 24, 2010
    Publication date: September 16, 2010
    Applicant: NTT DoCoMo, Inc.
    Inventors: Junichiro KAWAMOTO, Takahiro Asai, Kenichi Higuchi, Mamoru Sawahashi
  • Publication number: 20090225656
    Abstract: A base station according to the present invention includes: a detecting unit configured to detect a discard of the uplink user data received from a radio terminal; and a scheduling unit configured to transmit an AG or an RG instructing a decrease of an SG assigned to the radio terminal, when the discard of the uplink user data is detected by the detecting unit.
    Type: Application
    Filed: February 23, 2009
    Publication date: September 10, 2009
    Applicant: NTT DoCoMo, Inc.
    Inventors: Yukiko TAKAGI, Akihito Hanaki, Takahiro Hayashi, Junichiro Kawamoto, Yoshikazu Goto
  • Publication number: 20090225715
    Abstract: A mobile communication system is configured as a mobile station in a first communication state shifts to a second communication state when at least one high speed uplink packet communication compliant radio link is established by the mobile station.
    Type: Application
    Filed: February 19, 2009
    Publication date: September 10, 2009
    Applicant: NTT DoCoMo, Inc.
    Inventors: Junichiro KAWAMOTO, Akihito HANAKI, Takahiro HAYASHI, Yoshikazu GOTO, Yukiko TAKAGI
  • Publication number: 20090227256
    Abstract: A mobile communication method includes: causing a cell under control of a radio base station to determine an initial granted value when an uplink user data transmission channel is set up between a mobile station and the cell under the control of the radio base station; causing a radio network controller to notify the mobile station of the initial granted value determined by the cell under the control of the radio base station; and causing the mobile station to transmit uplink user data via the uplink user data transmission channel at a transmission rate corresponding to the initial granted value after the uplink user data transmission channel is set up, and the cell under the control of the radio base station sets the initial granted value to be equal to the granted value used in transmitting only a single data unit on the uplink user data transmission channel.
    Type: Application
    Filed: February 17, 2009
    Publication date: September 10, 2009
    Applicant: NTT DoCoMo, Inc.
    Inventors: Yoshikazu GOTO, Akihito Hanaki, Takahiro Hayashi, Junichiro Kawamoto, Yukiko Takagi
  • Publication number: 20090225726
    Abstract: A radio base station includes an assignment unit that selects a transmission rate control channel channelization code assigned to a fewest mobile stations, upon receipt of a communication start request from a mobile station, from among a plurality of transmission rate control channel channelization codes specified by a radio network controller and then assigns a selected transmission rate control channel channelization code to the mobile station.
    Type: Application
    Filed: February 23, 2009
    Publication date: September 10, 2009
    Applicant: NTT DoCoMo, Inc.
    Inventors: Akihito HANAKI, Akihiro FUJIWARA, Takahiro HAYASHI, Yoshikazu GOTO, Yukiko TAKAGI, Junichiro KAWAMOTO
  • Publication number: 20090225699
    Abstract: A base station includes: a determination unit that determines whether or not a total of an initial transmission rate and assigned transmission rates exceeds a maximum receiving transmission rate when the base station receives a communication start request from a radio terminal; a selecting unit that selects a decrease target terminal when the total of the initial transmission rate and the assigned transmission rates exceeds the maximum receiving transmission rate; and a transmitting unit that transmits transmission rate decrease data to the decrease target terminal, and the base station causes the total of the initial transmission rate and the assigned transmission rates to be equal to or less than the maximum receiving transmission rate by transmitting the transmission rate decrease data.
    Type: Application
    Filed: February 19, 2009
    Publication date: September 10, 2009
    Inventors: Yukiko Takagi, Akihito Hanaki, Takahiro Hayashi, Junichiro Kawamoto, Yoshikazu Goto
  • Publication number: 20090225713
    Abstract: The radio base station includes: a step of making a comparison between transmission format identification information received from the mobile station and transmission format identification information based on a data amount calculated in a step of calculating the data amount of uplink user data; and a step of retransmitting a calculated scheduling grant if the radio base station determines, based on the comparison result in the step of the comparison, that a data amount indicated by the transmission format identification information received from the mobile station is larger than the data amount calculated in the aforementioned step.
    Type: Application
    Filed: February 10, 2009
    Publication date: September 10, 2009
    Applicant: NTT DoCoMo, Inc.
    Inventors: Takahiro Hayashi, Akihito Hanaki, Junichiro Kawamoto, Yoshikazu Goto, Yukiko Takagi
  • Publication number: 20090201856
    Abstract: A base station includes a first selecting unit that selects a reduction target terminal, a first calculating unit that calculates a reduction amount of assigned transmission rate assigned to the reduction target terminal, a second selecting unit that selects an increase target terminal, a second calculating unit that calculates an increase amount of the assigned transmission rate assigned to the increase target terminal, and a transmitting unit that transmits transmission rate control date to a radio terminal. The second selecting unit selects the increase target terminal and the second calculating unit calculates the increase amount when the reduction target terminal is not selected by the first selecting unit.
    Type: Application
    Filed: February 4, 2009
    Publication date: August 13, 2009
    Applicant: NTT DoCoMo, Inc.
    Inventors: Takahiro HAYASHI, Akihito HANAKI, Junichiro KAWAMOTO, Yoshikazu GOTO, Yukiko TAKAGI
  • Publication number: 20090201870
    Abstract: A mobile communication method according to the present invention includes: controlling, at the radio base station NodeB, the transmission power in the DPCCH by use of an inner loop transmission power control based on a target SIR; transmitting, at the mobile station UE, the uplink packet, at the transmission power in the E-DPDCH, the transmission power being determined based on the SG and the transmission power in the DPCCH; and determining, at the radio base station NodeB, the target SIR, by use of an outer loop transmission power control based on a HARQ transmission number and a reception result of an uplink packet transmission of the HARQ transmission number, the HARQ transmission number indicating what number transmission in the HARQ retransmission control is the uplink packet transmission.
    Type: Application
    Filed: February 5, 2009
    Publication date: August 13, 2009
    Applicant: NTT DoCoMo, Inc.
    Inventors: Yoshikazu Goto, Akihito Hanaki, Takahiro Hayashi, Junichiro Kawamoto, Yukiko Takagi
  • Publication number: 20090197633
    Abstract: A mobile communication method includes: (A) assigning, at a radio network controller, a channelization code and a transmission timing for the mobile station on the basis of a status of use of a channelization code and a transmission timing in a sector other than a specific sector when the mobile station sets a radio link with the radio base station in the specific sector; and (B) notifying, from the radio base station, the mobile station of the transmission power control information via the transmission power control channel using the channelization code and the transmission timing assigned at the radio network controller.
    Type: Application
    Filed: February 3, 2009
    Publication date: August 6, 2009
    Applicant: NTT DoCoMo, Inc.
    Inventors: Junichiro KAWAMOTO, Akihito HANAKI, Takahiro HAYASHI, Yoshikazu GOTO, Yukiko TAKAGI
  • Publication number: 20090196246
    Abstract: A mobile communication method according to the present invention includes: notifying, from a MAC-e functional unit 10, to a first mobile station UE through a first E-AGCH, a transmission rate for the EUL in the first mobile station UE, in a 2 ms interval; notifying, from the MAC-e functional unit 10, to a second mobile station UE through a second E-AGCH, a transmission rate for the EUL in the second mobile station UE, in a 10 ms interval; notifying, from the MAC-e functional unit 10 to a MAC-hs functional unit 20, the number of the first E-AGCH and the number of the second E-AGCH, in each sub-frames; and determining, at the MAC-hs functional unit 20, a transmission power for a HS-PDSCH, based on the respective numbers of the first E-AGCH and the second E-AGCH.
    Type: Application
    Filed: January 28, 2009
    Publication date: August 6, 2009
    Applicant: NTT DoCoMo, Inc.
    Inventors: Yoshikazu GOTO, Akihito HANAKI, Takahiro HAYASHI, Junichiro KAWAMOTO, Yukiko TAKAGI
  • Publication number: 20090191886
    Abstract: A transmission rate control method according to the present invention includes: determining, at the radio base station NodeB, a maximum granted value that can be notified to the mobile station UE, in accordance with the happy bit notified from the mobile station UE; calculating, at the radio base station NodeB, as an allowable value to be notified to the mobile station UE, a granted value not more than the maximum granted value; notifying, from the radio base station NodeB to the mobile station UE, the granted value calculated at the radio base station NodeB, by using a transmission rate control channel; and transmitting, from the mobile station UE, the uplink user data, at a transmission rate corresponding to the granted value notified from the radio base station NodeB.
    Type: Application
    Filed: January 21, 2009
    Publication date: July 30, 2009
    Applicant: NTT DoCoMo, Inc.
    Inventors: Yoshikazu GOTO, Akihito Hanaki, Takahiro Hayashi, Junichiro Kawamoto, Yukiko Takagi
  • Publication number: 20090191887
    Abstract: A transmission rate control method according to the present invention includes: determining, at the radio base station NodeB, a maximum granted value that can be notified to the mobile station UE, in accordance with a throughput at which the uplink user data transmitted from the mobile station UE to the radio base station NodeB is successfully received at a point of time; calculating, at the radio base station NodeB, as an allowable value to be notified to the mobile station UE, a granted value not more than the maximum granted value; notifying, from the radio base station NodeB to the mobile station UE, the granted value calculated at the radio base station NodeB, by using a transmission rate control channel; and transmitting, from the mobile station UE, the uplink user data, at the transmission rate corresponding to the granted value notified from the radio base station NodeB.
    Type: Application
    Filed: January 22, 2009
    Publication date: July 30, 2009
    Applicant: NTT DoCoMo, Inc.
    Inventors: Yoshikazu Goto, Akihito Hanaki, Takahiro Hayashi, Junichiro Kawamoto, Yukiko Takagi
  • Publication number: 20090147745
    Abstract: A base station 100 includes: a specifying unit 125 configured to specify a decrease target TTI that indicates the TTI in which a sum of already assigned transmission rates is larger than an allowable receiving transmission rate; a selecting unit 126 configured to select, as a decrease target radio terminal, the radio terminal to which the TTI in the decrease UTI is assigned; and a scheduling unit 120a configured to transmit, to the decrease target radio terminal, transmission rate decrease data that is the transmission rate control data (AG or RG) for instructing a decrease of the transmission rate.
    Type: Application
    Filed: December 2, 2008
    Publication date: June 11, 2009
    Applicant: NTT DoCoMo, Inc.
    Inventors: Junichiro KAWAMOTO, Akihito Hanaki, Takahiro Hayashi, Yoshikazu Goto, Yukiko Takagi