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: 8665713
    Abstract: In a radio communication system in which a radio terminal 10 transmits, to a base station 100, uplink user data via an enhanced dedicated physical data channel, the base station 100 includes a base station side transmitter unit (scheduling unit 120a) configured to transmit, to the radio terminal 10, transmission rate decrease data for instructing a decrease of the transmission rate assigned to the radio terminal 10, when the uplink user data is not transmitted from the radio terminal 10 to the base station 100 by using the transmission rate assigned to the radio terminal 10.
    Type: Grant
    Filed: October 2, 2008
    Date of Patent: March 4, 2014
    Assignee: NTT DoCoMo, Inc.
    Inventors: Junichiro Kawamoto, Akihito Hanaki, Takahiro Hayashi, Yoshikazu Goto, Yukiko Takagi
  • Patent number: 8600397
    Abstract: The present invention relates to a mobile communication system which includes a base station, a mobile station for performing a communication with the base station, and a radio network controller for controlling the communication between the base station and the mobile station. The mobile communication system comprises a controller configured to control a communication state of the communication between the base station and the mobile station according to a congestion state of an uplink.
    Type: Grant
    Filed: September 21, 2007
    Date of Patent: December 3, 2013
    Assignee: NTT DoCoMo, Inc.
    Inventors: Hiroyuki Ishii, Takahiro Hayashi, Akihito Hanaki, Junichiro Kawamoto, Yoshikazu Goto, Koji Furutani
  • Patent number: 8432795
    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: Grant
    Filed: February 23, 2009
    Date of Patent: April 30, 2013
    Assignee: NTT DoCoMo, Inc.
    Inventors: Yukiko Takagi, Akihito Hanaki, Takahiro Hayashi, Junichiro Kawamoto, Yoshikazu Goto
  • Patent number: 8379580
    Abstract: A radio terminal 10 transmits, to a base station 100, uplink scheduling information including at least a transmission power ratio (UPH) indicating a ratio of a maximum transmission power to a transmission power of a DPCCH. The base station 100 transmits, to the radio terminal 10, transmission rate decrease data that instructs a decrease of a transmission rate assigned to the radio terminal 10, when the transmission power ratio included in the uplink scheduling information is below a first threshold.
    Type: Grant
    Filed: October 21, 2008
    Date of Patent: February 19, 2013
    Assignee: NTT DoCoMo, Inc.
    Inventors: Yoshikazu Goto, Akihito Hanaki, Takahiro Hayashi, Junichiro Kawamoto, Yukiko Takagi
  • Patent number: 8375270
    Abstract: A signal transmission method in a radio multiplex transmission system that includes serial-to-parallel converting of serial data to be transmitted into N parallel data series and independently performing an error-correcting encoding process on the parallel signals of the N data series. The method further includes parallel-to-serial converting of the parallel signals encoded with error-correcting codes, performing an interleaving process on the parallel-to-serial converted signals and serial-to-parallel converting the interleaved signals into L parallel data series and transmitting each of the L data series. The transmitted signals are then received and separated into M data series and are parallel-to-serial converted and a deinterleaving process is performed.
    Type: Grant
    Filed: May 24, 2010
    Date of Patent: February 12, 2013
    Assignee: NTT DoCoMo, Inc.
    Inventors: Junichiro Kawamoto, Takahiro Asai, Kenichi Higuchi, Mamoru Sawahashi
  • Patent number: 8340019
    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: Grant
    Filed: February 19, 2009
    Date of Patent: December 25, 2012
    Assignee: NTT DoCoMo, Inc.
    Inventors: Yukiko Takagi, Akihito Hanaki, Takahiro Hayashi, Junichiro Kawamoto, Yoshikazu Goto
  • Patent number: 8260309
    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: Grant
    Filed: January 22, 2009
    Date of Patent: September 4, 2012
    Assignee: NTT DoCoMo, Inc.
    Inventors: Yoshikazu Goto, Akihito Hanaki, Takahiro Hayashi, Junichiro Kawamoto, Yukiko Takagi
  • Patent number: 8249633
    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 TTI 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: Grant
    Filed: December 2, 2008
    Date of Patent: August 21, 2012
    Assignee: NTT DoCoMo, Inc.
    Inventors: Junichiro Kawamoto, Akihito Hanaki, Takahiro Hayashi, Yoshikazu Goto, Yukiko Takagi
  • Patent number: 8185126
    Abstract: A communication control method includes the step of restricting the number of communication channels used dedicatedly by each of mobile stations or a resource of communication channels used dedicatedly by each of the mobile stations when both communication channel shared by the mobile stations and communication channels used dedicatedly by each of the mobile stations are simultaneously used in a mobile communication system.
    Type: Grant
    Filed: August 16, 2007
    Date of Patent: May 22, 2012
    Assignee: NTT DoCoMo, Inc.
    Inventors: Yoshikazu Goto, Hiroyuki Ishii, Takahiro Hayashi, Akihito Hanaki, Junichiro Kawamoto, Koji Furutani
  • Patent number: 8185125
    Abstract: A transmission rate control method according to the present invention includes: selecting, at the radio base station NodeB, increase-allowed mobile stations whose uplink user data transmission rate can be increased at a predetermined TTI; equally dividing, at the radio base station NodeB, an available radio resource at the predetermined TTI, based on the number of increase-allowed mobile stations or the number of E-AGCHs that can be transmitted in the cell; and adding, at the radio base station NodeB, the radio resource equally divided by a radio resource allocating unit 13A, to each radio resources allocated to each mobile stations to which a transmission rate control channel (E-AGCH) can be transmitted and is one of the increase-allowed mobile stations.
    Type: Grant
    Filed: October 21, 2008
    Date of Patent: May 22, 2012
    Assignee: NTT DoCoMo, Inc.
    Inventors: Yoshikazu Goto, Akihito Hanaki, Takahiro Hayashi, Junichiro Kawamoto, Yukiko Takagi
  • Patent number: 8179850
    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: Grant
    Filed: February 19, 2009
    Date of Patent: May 15, 2012
    Assignee: NTT DoCoMo, Inc.
    Inventors: Junichiro Kawamoto, Akihito Hanaki, Takahiro Hayashi, Yoshikazu Goto, Yukiko Takagi
  • Patent number: 8169929
    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: Grant
    Filed: February 17, 2009
    Date of Patent: May 1, 2012
    Assignee: NTT DoCoMo, Inc.
    Inventors: Yoshikazu Goto, Akihito Hanaki, Takahiro Hayashi, Junichiro Kawamoto, Yukiko Takagi
  • Patent number: 8155654
    Abstract: A transmission rate control method including: notifying, from the mobile station UE to the radio base station NodeB, a data amount in a transmission buffer of the mobile station UE; determining, at the radio base station NodeB, a maximum allowable value that can be notified to the mobile station UE, in accordance with the data amount in the transmission buffer; calculating, at the radio base station NodeB, as a granted value to be notified to the mobile station UE, a value that does not exceed the maximum allowable value, notifying, from the radio base station Node B to the mobile station UE, the granted value calculated at the radio base station UE, by using a transmission rate control channel; and transmitting, at 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: Grant
    Filed: November 25, 2008
    Date of Patent: April 10, 2012
    Assignee: NTT DoCoMo, Inc.
    Inventors: Yoshikazu Goto, Akihito Hanaki, Takahiro Hayashi, Junichiro Kawamoto, Yukiko Takagi
  • Patent number: 8150444
    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: Grant
    Filed: February 3, 2009
    Date of Patent: April 3, 2012
    Assignee: NTT DoCoMo, Inc.
    Inventors: Junichiro Kawamoto, Akihito Hanaki, Takahiro Hayashi, Yoshikazu Goto, Yukiko Takagi
  • Patent number: 8144656
    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: Grant
    Filed: February 10, 2009
    Date of Patent: March 27, 2012
    Assignee: NTT DoCoMo, Inc.
    Inventors: Takahiro Hayashi, Akihito Hanaki, Junichiro Kawamoto, Yoshikazu Goto, Yukiko Takagi
  • Patent number: 8144822
    Abstract: A noise power estimation apparatus is disclosed. The noise power estimation apparatus includes: a part for calculating correlation between a received signal and a pilot signal so as to obtain a received power of the pilot signal for each path; a part for removing a multipath interference component from the received power of the pilot signal by using a predetermined power ratio between the pilot signal and a data signal so as to obtain a corrected received power of the pilot signal; a part for estimating an estimated total power of the pilot signal and the data signal included in the received signal based on the corrected received power and the predetermined power ratio; and a part for subtracting the estimated total power from a total power of the received signal so as to obtain a noise power.
    Type: Grant
    Filed: May 8, 2008
    Date of Patent: March 27, 2012
    Assignee: NTT DoCoMo, Inc.
    Inventors: Junichiro Kawamoto, Noriyuki Maeda, Kenichi Higuchi, Mamoru Sawahashi
  • Patent number: 8139534
    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: Grant
    Filed: February 5, 2009
    Date of Patent: March 20, 2012
    Assignee: NTT DoCoMo, Inc.
    Inventors: Yoshikazu Goto, Akihito Hanaki, Takahiro Hayashi, Junichiro Kawamoto, Yukiko Takagi
  • Patent number: 8102898
    Abstract: A corrected channel estimating apparatus is disclosed, which is capable of removing side-lobe components mutually leaking into transmission paths from channel estimates to increase the accuracy. A channel estimation unit calculates channel estimates for a plurality of transmission paths due to a signal that arrives through multipath. A channel estimate correction unit removes side-lobe components mutually leaking into the transmission paths from the channel estimates calculated by the channel estimation unit to correct the channel estimates. In this way, the corrected channel estimating apparatus estimates transmission paths of a multipath.
    Type: Grant
    Filed: February 24, 2006
    Date of Patent: January 24, 2012
    Assignees: NEC Corporation, NTT DoCoMo, Inc.
    Inventors: Mariko Matsumoto, Shousei Yoshida, Noriyuki Maeda, Junichiro Kawamoto
  • Patent number: 8078186
    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: Grant
    Filed: January 21, 2009
    Date of Patent: December 13, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Yoshikazu Goto, Akihito Hanaki, Takahiro Hayashi, Junichiro Kawamoto, Yukiko Takagi
  • Patent number: 8050703
    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: Grant
    Filed: January 28, 2009
    Date of Patent: November 1, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Yoshikazu Goto, Akihito Hanaki, Takahiro Hayashi, Junichiro Kawamoto, Yukiko Takagi