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).

  • Publication number: 20090137242
    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: Application
    Filed: November 25, 2008
    Publication date: May 28, 2009
    Applicant: NTT DoCoMo, Inc.
    Inventors: Yoshikazu Goto, Akihito Hanaki, Takahiro Hayashi, Junichiro Kawamoto, Yukiko Takagi
  • Publication number: 20090103479
    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: Application
    Filed: October 21, 2008
    Publication date: April 23, 2009
    Applicant: NTT DoCoMo, Inc.
    Inventors: Yoshikazu Goto, Akihito Hanaki, Takahiro Hayashi, Junichiro Kawamoto, Yukiko Takagi
  • Publication number: 20090104914
    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: Application
    Filed: October 21, 2008
    Publication date: April 23, 2009
    Applicant: NTT DoCoMo, Inc.
    Inventors: Yoshikazu GOTO, Akihito Hanaki, Takahiro Hayashi, Junichiro Kawamoto, Yukiko Takagi
  • Publication number: 20090092104
    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: Application
    Filed: October 2, 2008
    Publication date: April 9, 2009
    Applicant: NTT DOCOMO, INC.
    Inventors: Junichiro KAWAMOTO, Akihito HANAKI, Takahiro HAYASHI, Yoshikazu GOTO, Yukiko TAKAGI
  • Publication number: 20090093256
    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: Application
    Filed: October 2, 2008
    Publication date: April 9, 2009
    Applicant: NTT DoCoMo, Inc.
    Inventors: Junichiro KAWAMOTO, Akihito Hanaki, Takahiro Hayashi, Yoshikazu Goto, Yukiko Takagi
  • Publication number: 20090093254
    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: Application
    Filed: October 7, 2008
    Publication date: April 9, 2009
    Applicant: NTT DoCoMo, Inc.
    Inventors: Yoshikazu Goto, Akihito Hanaki, Takahiro Hayashi, Junichiro Kawamoto, Yukiko Takagi
  • Publication number: 20090092120
    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 relative grant to the radio terminal 10 without transmitting the absolute grant. The non-serving cell includes an RG controlling unit 133 configured to control a transmission interval of an RG for instructing a decrease of the uplink user data transmission rate.
    Type: Application
    Filed: October 7, 2008
    Publication date: April 9, 2009
    Applicant: NTT DoCoMo, Inc.
    Inventors: Yoshikazu GOTO, Akihito Hanaki, Takahiro Hayashi, Junichiro Kawamoto, Yukiko Takagi
  • Publication number: 20090059883
    Abstract: Provided are a radio base station and a method of receiving a physical control channel which are capable of achieving enhanced data-transmission efficiency of an uplink physical channel when a code division multiple access scheme is used. The radio base station includes: a correlation unit configured to determine a degree of correlation between a code word transmitted from the mobile device through a physical control channel and each replica of the code word, and to then select the replica having a higher degree of correlation than a predetermined degree; an identification unit configured to identify a control information piece contained in the selected replica; and a code-word replica generator configured to reduce the number of the replicas when the control information piece is identified.
    Type: Application
    Filed: September 5, 2008
    Publication date: March 5, 2009
    Applicant: NTT DoCoMo, Inc.
    Inventors: Junichiro Kawamoto, Akihito Hanaki, Takahiro Hayashi, Yoshikazu Goto, Yukiko Takagi
  • Publication number: 20090046588
    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: Application
    Filed: February 24, 2006
    Publication date: February 19, 2009
    Applicant: NEC CORPORATION
    Inventors: Mariko Matsumoto, Shousei Yoshida, Noriyuki Maeda, Junichiro Kawamoto
  • Publication number: 20080253432
    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: Application
    Filed: May 8, 2008
    Publication date: October 16, 2008
    Applicant: NTT DoCoMo, Inc.
    Inventors: Junichiro KAWAMOTO, Noriyuki Maeda, Kenichi Higuchi, Mamoru Sawahashi
  • Patent number: 7421009
    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 13, 2005
    Date of Patent: September 2, 2008
    Assignee: NTT DoCoMo, Inc.
    Inventors: Junichiro Kawamoto, Noriyuki Maeda, Kenichi Higuchi, Mamoru Sawahashi
  • Publication number: 20080207186
    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: Application
    Filed: August 22, 2007
    Publication date: August 28, 2008
    Applicant: NTT DoCoMo, Inc.
    Inventors: Junichiro Kawamoto, Takahiro Hayashi, Hiroyuki Ishii, Akihito Hanaki, Yoshikazu Goto, Koji Furutani
  • Patent number: 7379745
    Abstract: A path searcher used in a receiver includes a power delay profile generating unit configured to generate a power delay profile based on a signal received by the receiver, a sidelobe generating unit configured to identify a sidelobe component of a path contained in the power delay profile based on a response characteristic of a band-limiting filter of the receiver, a sidelobe removing unit configured to remove the sidelobe component from the power delay profile to produce a corrected power delay profile, and a path timing detection unit configured to detect a path timing based on the corrected power delay profile.
    Type: Grant
    Filed: May 5, 2005
    Date of Patent: May 27, 2008
    Assignee: NTT DoCoMo, Inc.
    Inventors: Junichiro Kawamoto, Noriyuki Maeda, Kenichi Higuchi, Mamoru Sawahashi
  • Publication number: 20080081637
    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: Application
    Filed: September 28, 2007
    Publication date: April 3, 2008
    Applicant: NTT DoCoMo, Inc.
    Inventors: Hiroyuki Ishii, Takahiro Hayashi, Akihito Hanaki, Junichiro Kawamoto, Yoshikazu Goto, Koji Furutani
  • Publication number: 20080076442
    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: Application
    Filed: September 21, 2007
    Publication date: March 27, 2008
    Applicant: NTT DoCoMo, Inc.
    Inventors: Hiroyuki Ishii, Takahiro Hayashi, Akihito Hanaki, Junichiro Kawamoto, Yoshikazu Goto, Koji Furutani
  • Publication number: 20080045223
    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: Application
    Filed: August 16, 2007
    Publication date: February 21, 2008
    Applicant: NTT DoCoMo, Inc.
    Inventors: Yoshikazu Goto, Hiroyuki Ishii, Takahiro Hayashi, Akihito Hanaki, Junichiro Kawamoto, Koji Furutani
  • Publication number: 20070197166
    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: Application
    Filed: March 4, 2005
    Publication date: August 23, 2007
    Applicants: NTT DoCoMo, Inc, NEC Corporation
    Inventors: Junichiro Kawamoto, Noriyuki Maeda, Kenichi Higuchi, Mamoru Sawahashi, Shousei Yoshida, Masayuki Kimata
  • Publication number: 20070162819
    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: September 7, 2004
    Publication date: July 12, 2007
    Applicant: NTT DoMo , Inc.
    Inventors: Junichiro Kawamoto, Takahiro Asai, Kenichi Higuchi, Mamoru Sawahashi
  • Publication number: 20050259721
    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: Application
    Filed: May 13, 2005
    Publication date: November 24, 2005
    Applicant: NTT DoCoMo, Inc.
    Inventors: Junichiro Kawamoto, Noriyuki Maeda, Kenichi Higuchi, Mamoru Sawahashi
  • Publication number: 20050255819
    Abstract: A path searcher (304) used in a receiver includes a power delay profile generating unit (402) configured to generate a power delay profile based on a signal received by the receiver, a sidelobe generating unit (406) configured to identify a sidelobe component of a path contained in the power delay profile based on a response characteristic of a band-limiting filter of the receiver, a sidelobe removing unit (407) configured to remove the sidelobe component from the power delay profile to produce a corrected power delay profile, and a path timing detection unit (408) configured to detect a path timing based on the corrected power delay profile.
    Type: Application
    Filed: May 5, 2005
    Publication date: November 17, 2005
    Applicant: NTT DoCoMo, Inc.
    Inventors: Junichiro Kawamoto, Noriyuki Maeda, Kenichi Higuchi, Mamoru Sawahashi