Patents by Inventor Masafumi Usuda

Masafumi Usuda 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: 8073404
    Abstract: An object of the present invention is to specify how a transmission diversity station that implements an EUL should apply a transmission antenna diversity to an E-HICH, an E-RGCH and an E-AGCH. The present invention relates to a mobile communication method for transmitting a signal from a base station to a mobile station via a downlink. In the method, a closed loop transmission antenna diversity is applied to a dedicated channel of the downlink, and an open loop transmission antenna diversity is applied to a control channel of the downlink in conformity with an uplink high efficient transmission method.
    Type: Grant
    Filed: September 16, 2005
    Date of Patent: December 6, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Anil Umesh, Masafumi Usuda, Takehiro Nakamura
  • Patent number: 8060023
    Abstract: In a mobile communication system according to the present invention, a data transmitting-side apparatus is configured to retransmit a transmission data block according to a transmission acknowledgement signal transmitted from a data receiving-side apparatus. The data receiving-side apparatus includes: a maximum number-of-retransmissions manager unit configured to manage the maximum number of retransmissions of the transmission data block; and a transmission acknowledgement signal transmitter unit configured not to transmit the transmission acknowledgement signal, when the number of retransmissions of the transmission data block reaches the maximum number of retransmissions.
    Type: Grant
    Filed: November 9, 2005
    Date of Patent: November 15, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Masafumi Usuda, Anil Umesh, Takehiro Nakamura
  • Patent number: 8041381
    Abstract: A radio network controller includes a block error detection unit configured to receive a data block from the base station and to detect a block error, and a target SIR calculation unit configured to calculate a target SIR based on the detected block error rate. The target calculation unit sets a first time section, which indicates a time section from a detection of the block error to the notification of the target SIR is to the base station when the block error is detected, shorter than a second time section, which indicates a time section from the detection of the block error to the notification of the target SIR to the base station when the block error is not detected.
    Type: Grant
    Filed: January 10, 2007
    Date of Patent: October 18, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Masafumi Usuda, Anil Umesh, Hidehiro Ando, Takuya Sato, Shinichi Sasaki, Kouji Makino
  • Patent number: 8032171
    Abstract: The present invention enables to reduce deterioration in an uplink capacity due to a transmission power of an E-DPCCH, by setting, at the radio network controller, a suitable transmission power offset depending on a situation. A transmission power control method according to the present invention includes: measuring, at the radio base station, a reception quality of the enhanced dedicated physical control channel; notifying, from the radio base station to a radio network controller, the measured reception quality of the enhanced dedicated physical control channel; setting, at the radio network controller, a transmission power offset for the enhanced dedicated physical control channel to a dedicated physical control channel, in accordance with the reception quality of the enhanced dedicated physical control channel; and notifying, from the radio network controller to the mobile station, the set transmission power offset.
    Type: Grant
    Filed: May 2, 2006
    Date of Patent: October 4, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Masafumi Usuda, Anil Umesh
  • Patent number: 8031648
    Abstract: A packet transmission control device relating to the present invention includes: a storage unit configured to store a transmission resource available for use in the packet transmission, radio quality information on the downlink, and a transmission method to be used in the packet transmission while associating them with one another; a determination unit configured to determine a transmission method to be used in the packet transmission on the basis of the radio quality information, on the downlink reported from the mobile stations and the transmission resource available for use in the packet transmission, by referring to the storage unit; and a packet transmission unit configured to transmit the packet by using the determined transmission method.
    Type: Grant
    Filed: October 17, 2005
    Date of Patent: October 4, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Hiroyuki Ishii, Akihito Hanaki, Masafumi Usuda
  • Patent number: 7990859
    Abstract: The present invention relates to a packet transmission control device which controls transmission of packets to a plurality of mobile stations. A scheduling unit of the packet transmission control device according to the present invention is configured to schedule the packets to each of the plurality of mobile stations, based on an average transmission rate, a minimum guaranteed transmission rate, a scheduling frequency and capability information.
    Type: Grant
    Filed: May 10, 2005
    Date of Patent: August 2, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Hiroyuki Ishii, Yoshimasa Imamura, Akihito Hanaki, Takehiro Nakamura, Shinya Tanaka, Masafumi Usuda
  • Patent number: 7991415
    Abstract: The present invention provides a transmission rate control method for controlling the transmission rate of uplink user data, including the step of; a radio network controller notifies to a radio base station and a mobile station an effective period of an absolute transmission rate control channel, when a call is established or when a serving cell is changed; a radio base station determines whether or not to transmit the absolute transmission rate control channel to each of mobile stations which is performing a communication with the radio base station; and each of the mobile stations determines the transmission rate of the uplink user data, based on a maximum allowable transmission rate mapped to the absolute transmission rate control channel notified by the radio base station.
    Type: Grant
    Filed: March 22, 2006
    Date of Patent: August 2, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Masafumi Usuda, Anil Umesh, Takehiro Nakamura
  • Patent number: 7978663
    Abstract: The present invention relates to a radio resource control method for controlling a radio resource for transmitting user data via an uplink by a mobile station. A radio base station reports, to a radio network controller, at a predetermined timing, a maximum allowable transmission rate of the user data, which is signaled to the mobile station connected to the radio base station. The radio network controller controls the radio resource based on the reported maximum allowable transmission rate.
    Type: Grant
    Filed: January 11, 2006
    Date of Patent: July 12, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Masafumi Usuda, Anil Umesh, Takehiro Nakamura
  • Patent number: 7974231
    Abstract: A communication control apparatus (30, 10) used in a mobile communication system includes: means (32, 12) that derives a second target communication quality Q2 for TFs other than a reference format from a first target communication quality for the reference format in a plurality of TFs provide for communicating with an upper layer of a physical channel; means (33, 13) that derives a third target communication quality different from the first target communication quality from the first and the second target communication qualities; and means that sets the third target communication quality to be a target value of transmission power control.
    Type: Grant
    Filed: April 25, 2006
    Date of Patent: July 5, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Hiroyuki Ishii, Anil Umesh, Masafumi Usuda, Takehiro Nakamura
  • Publication number: 20110142102
    Abstract: In this invention, a channel estimation value of data symbols of a data channel is calculated by weighting and averaging pilot symbols in a parallel time multiplexing method. Also, a channel estimation value of data symbols during each data symbol interval is calculated by dividing data symbols in a slot into a plurality of data symbol intervals, selecting pilot symbols suitable for calculation of a channel estimation value of data symbols during each data symbol interval and weighting and averaging that pilot symbols. Also, a fading frequency is detected based on an inner product value of pilot symbols. Weighting factors are changed based on the detected fading frequency. Also, a channel estimation value is calculated by weighting and averaging pilot signals using a plurality of weighting sequences. The calculated channel estimation value is used to demodulate received data. The output data with the highest quality is selected by judging reliability of these plurality of demodulated data.
    Type: Application
    Filed: February 23, 2011
    Publication date: June 16, 2011
    Applicant: NTT DoCoMo, Inc.
    Inventors: Yukihiko Okumura, Hidehiro Ando, Masafumi Usuda, Yoshihiro Ishikawa, Seizo Onoe
  • Patent number: 7941168
    Abstract: A mobile communication system is configured to control a transmission rate of user data to be transmitted from a mobile station to a radio base station via an uplink transmission rate allocation shared physical control channel, and to transmit user data from the radio base station to the mobile station via a downlink shared physical data channel. Transmission frame timing of the uplink transmission rate allocation shared physical control channel is synchronized with transmission frame timing of the downlink shared physical data channel.
    Type: Grant
    Filed: February 1, 2006
    Date of Patent: May 10, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Anil Umesh, Masafumi Usuda, Takehiro Nakamura
  • Patent number: 7937111
    Abstract: A wireless base station apparatus (100) used in a wireless communications system includes a statistical processing unit (140) that performs statistical processing on downlink radio quality information reported from a wireless communications terminal device; a radio quality information offsetting unit (160) that adjusts the statistically processed downlink radio quality information based on a downlink transmission confirmation (ACK/NACK/DTX) message transmitted from the wireless communications terminal device and a required downlink quality; a transport format determination unit (170) that determines a downlink transport format based on the statistically processed radio quality information or the offset-adjusted radio quality information; and a transmitting unit (111) that transmits a downlink channel with the determined downlink transport format.
    Type: Grant
    Filed: October 16, 2007
    Date of Patent: May 3, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Hiroyuki Ishii, Masafumi Usuda, Yoshimasa Imamura, Akihito Hanaki
  • Patent number: 7929592
    Abstract: A channel estimation value of data symbols of a data channel is calculated by weighting and averaging pilot symbols in a parallel time multiplexing method. Also, a channel estimation value of data symbols during each data symbol interval is calculated by dividing data symbols in a slot into a plurality of data symbol intervals, selecting pilot symbols suitable for calculation of a channel estimation value of data symbols during each data symbol interval and weighting and averaging that pilot symbols. Also, a fading frequency is detected based on an inner product value of pilot symbols. Weighting factors are changed based on the detected fading frequency. Also, a channel estimation value is calculated by weighting and averaging pilot signals using a plurality of weighting sequences. The calculated channel estimation value is used to demodulate received data.
    Type: Grant
    Filed: March 31, 2000
    Date of Patent: April 19, 2011
    Assignee: NTT Docomo, Inc.
    Inventors: Yukihiko Okumura, Hidehiro Ando, Masafumi Usuda, Yoshihiro Ishikawa, Seizo Onoe
  • Patent number: 7907914
    Abstract: To prevent consecutive transmission of a relative transmission rate control channel (RGCH) including a “Down” command and minimize deterioration in the service quality due to “Down” commands from non-serving cells, a transmission rate control method controls, at a mobile station, a transmission rate of uplink user data by using a first relative transmission rate control channel received from a serving cell and a second relative transmission rate control channel received from a non-serving cell. In the transmission rate control method, a maximum frequency of transmitting the second relative transmission rate control channel which includes a down command for instructing to decrease the transmission rate of the uplink user data is a value fixed in a mobile communication system or a value notified by a radio network controller.
    Type: Grant
    Filed: April 28, 2006
    Date of Patent: March 15, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Masafumi Usuda, Anil Umesh
  • Patent number: 7894845
    Abstract: The present invention performs an outer loop transmission power control in a more stable manner by preventing a status of being unable to detect an Enhanced Dedicated Physical Control Channel (E-DPCCH). A transmission power control method according to the present application includes: generating, at a mobile station UE, a transport block having a predetermined minimum transport block size, when information to be transmitted to a radio base station Node B does not exist; transmitting, from the mobile station UE to the radio base station Node B, the transport block by a transmission timing predetermined by a mobile communication system or a transmission timing notified from a radio network controller RNC; receiving, at the radio base station Node B, the transport block in accordance with the transmission timing; and controlling, at the radio base station Node B, the transmission power, according to a reception quality of the transport block.
    Type: Grant
    Filed: May 2, 2006
    Date of Patent: February 22, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Masafumi Usuda, Anil Umesh
  • Patent number: 7889698
    Abstract: A transmission rate control method for controlling, at a mobile station, a transmission rate of uplink user data, based on a dedicated absolute transmission rate of uplink user data received via a dedicated E-AGCH which is transmitted using a dedicated identifier for the mobile station or a common absolute transmission rate of uplink user data received via a common E-AGCH which is transmitted using a common identifier for mobile stations which satisfy a predetermined condition, includes: storing, at the mobile station, the common absolute transmission rate of the uplink user data received via the common E-AGCH; and deleting, at the mobile station, the stored common absolute transmission rate of the uplink user data when changing a serving cell for the mobile station.
    Type: Grant
    Filed: August 21, 2006
    Date of Patent: February 15, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Masafumi Usuda, Anil Umesh
  • Patent number: 7885652
    Abstract: A mobile station includes; a retransmission control section configured to perform retransmission control of user data in a physical layer and a MAC sublayer with one or more radio base stations; and a threshold setting section configured to set a threshold used for determining presence or absence of an acknowledgement signal of the user data, according to the number of the radio base stations to which the mobile station connects.
    Type: Grant
    Filed: March 16, 2006
    Date of Patent: February 8, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Anil Umesh, Masafumi Usuda, Hiroyuki Ishii, Takehiro Nakamura
  • Patent number: 7885617
    Abstract: A base station (10) according to the present invention includes: a plurality of amplifiers (15a, 15b) configured to amplify radio frequency signals; a plurality of antennas (16a, 16b) configured to transmit the RF signals amplified by the plurality of amplifiers (15a, 15b); a judging unit (123) configured to judge whether or not to transmit the RF signals by applying a transmission diversity using the plurality of antennas (16a, 16b); and a baseband signal processor unit (12) configured to generate baseband signals having an identical symbol pattern and an identical amplitude, as baseband signals that are bases of the RF signals to be transmitted from the plurality of antennas (16a, 16b), when the judging unit (123) determines not to apply the transmission diversity.
    Type: Grant
    Filed: October 31, 2005
    Date of Patent: February 8, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Masafumi Usuda, Hiroyuki Ishii, Takehiro Nakamura
  • Patent number: 7885265
    Abstract: A transmission control method for uplink user data in a mobile communication system in which a plurality of HARQ processes is applied to the uplink user data, includes: classifying, at the radio network controller, each HARQ process into any of a scheduled transmission process, a non-scheduled transmission process, or a scheduled and non-scheduled transmission process in which either of the scheduled transmission or the non-scheduled transmission is performed; notifying, at the radio network controller, the classification result to the mobile station; and transmitting, at the mobile station, the uplink user data in each HARQ process to the radio base station using the scheduled transmission or the non-scheduled transmission, based on the notified classification result.
    Type: Grant
    Filed: August 29, 2006
    Date of Patent: February 8, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Masafumi Usuda, Anil Umesh
  • Publication number: 20110002318
    Abstract: It is an objective of the present invention to efficiently use an uplink radio resource, when transmitting user data based on an uplink high efficient transmission method. A mobile station according to the present invention includes a transmission section configured to transmit high efficient uplink data channel frames for transmitting user data based on the uplink high efficient transmission method, so that transmission timings of the high efficient uplink data channel frames are synchronized among mobile stations located in a single area.
    Type: Application
    Filed: September 15, 2010
    Publication date: January 6, 2011
    Applicant: NTT DOCOMO, INC.
    Inventors: Anil UMESH, Masafumi USUDA, Takehiro NAKAMURA