Patents by Inventor Masataka Umeda

Masataka Umeda 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: 8351403
    Abstract: A data allocation method in a wireless communication system in which data is allocated in both a time axis direction and frequency axis direction, and data is transmitted between a mobile station and base station according to an allocated schedule, the allocation method including: measuring propagation path information between the mobile station and the base station; and modifying an allocation width of a burst in the time axis direction or in the frequency axis direction based on the propagation path information.
    Type: Grant
    Filed: August 12, 2009
    Date of Patent: January 8, 2013
    Assignee: Fujitsu Limited
    Inventors: Masataka Umeda, Hideki Furudate
  • Publication number: 20120307944
    Abstract: A receiving apparatus includes a symbol timing detection unit, a Fourier transform unit, a first symbol timing correction unit, and an interpolation synthesis unit. The symbol timing detection unit is configured to detect a Fourier transform start position from a received transmitting signal of a symbol unit, the Fourier transform unit is configured to perform a Fourier transform using the detected Fourier transform start position. The first symbol timing correction unit is configured to calculate and correct an amount of change between the Fourier transform start position of a reference symbol and the detected Fourier transform start position, and the interpolation synthesis unit is configured to perform an interpolation synthesis of a plurality of delay profiles corresponding to a plurality of symbols including the reference symbol and a symbol in which the amount of change is corrected.
    Type: Application
    Filed: April 9, 2012
    Publication date: December 6, 2012
    Applicants: FUJITSU SEMICONDUCTOR LIMITED, FUJITSU LIMITED
    Inventors: Hiroaki TAKAGI, Naoto ADACHI, Masataka Umeda
  • Publication number: 20120300883
    Abstract: A demodulation circuit includes a hard decision process unit and a soft decision process unit. The hard decision process unit is configured to perform a hard decision process using a demodulated signal, and the demodulated signal is a demodulated received signal. The soft decision process unit is configured to determine a range of assignment with respect to a transitioning part in the demodulated signal, calculate a likelihood value of a bit, and perform a soft decision process.
    Type: Application
    Filed: April 9, 2012
    Publication date: November 29, 2012
    Applicants: FUJITSU SEMICONDUCTOR LIMITED, FUJITSU LIMITED
    Inventors: Naoto ADACHI, Masataka UMEDA
  • Patent number: 8254509
    Abstract: A receiver receives a reception signal subjected to orthogonal frequency division multiplexing modulation or orthogonal frequency division multiple access modulation. The receiver has: an array antenna for receiving the reception signal; adaptive equalizers provided in each of the plurality of antennas, and reducing advanced or delayed waves having a delay time to a main wave in the reception signal; a spatial diversity combining portion which multiplies output signals of the adaptive equalizers by a weighting coefficient and adds the multiplied signals; a weight control portion generating the weighting coefficient; and an equalizer setting unit which estimates an arrival angle and a delay time for each path of the reception signal, and based on the estimation, decides an interference wave to be eliminated by the adaptive equalizers among interference waves, and sets in the adaptive equalizers the delay time of the decided interference wave.
    Type: Grant
    Filed: February 16, 2011
    Date of Patent: August 28, 2012
    Assignee: Fujitsu Limited
    Inventors: Masataka Umeda, Takanori Iwamatsu
  • Publication number: 20110235688
    Abstract: A receiving device includes: a receiver that receives frequency multiplex signal; a first Fourier transformation unit that transforms the received frequency multiplex signal to frequency domain signal; a first time-domain waveform generator that generates a first time-domain waveform by performing inverse Fourier transformation of a plurality of pilot signals which are inserted into the frequency multiplex signal; a second time-domain waveform generator that generates a second time-domain waveform having an aliasing period on the basis of the received frequency multiplex signal; a second Fourier transformation unit that synthesizes the first time-domain waveform to the second time-domain waveform and transforms the synthesized time-domain waveform to frequency-domain information; and a propagation-path compensation unit that compensates a propagation-path of the frequency multiplex signal which is output from the first Fourier transformation unit in accordance with information transformed by the second Fourie
    Type: Application
    Filed: March 11, 2011
    Publication date: September 29, 2011
    Applicant: FUJITSU LIMITED
    Inventor: Masataka UMEDA
  • Patent number: 8010161
    Abstract: A radio base station for performing communication through three or more frequency bands based on orthogonal frequency division multiplexing includes a transmission unit configured to transmit a first channel through at least one of the three or more frequency bands and to transmit a second channel having smaller power than the first channel through at least another one of the three or more frequency bands, the first channel and the second channel being transmittable concurrently in time, a reception condition detecting unit configured to detect a reception condition of one or more mobile stations residing within a local cell, and a scheduling unit configured to select one of the first channel and the second channel, a modulation scheme, and a transmission power to be used for at least a downlink to one of the mobile stations based on the detected reception condition.
    Type: Grant
    Filed: August 28, 2008
    Date of Patent: August 30, 2011
    Assignee: Fujitsu Limited
    Inventors: Masataka Umeda, Hiromu Matsuzawa
  • Publication number: 20110200089
    Abstract: A receiver receives a reception signal subjected to orthogonal frequency division multiplexing modulation or orthogonal frequency division multiple access modulation. The receiver has: an array antenna for receiving the reception signal; adaptive equalizers provided in each of the plurality of antennas, and reducing advanced or delayed waves having a delay time to a main wave in the reception signal; a spatial diversity combining portion which multiplies output signals of the adaptive equalizers by a weighting coefficient and adds the multiplied signals; a weight control portion generating the weighting coefficient; and an equalizer setting unit which estimates an arrival angle and a delay time for each path of the reception signal, and based on the estimation, decides an interference wave to be eliminated by the adaptive equalizers among interference waves, and sets in the adaptive equalizers the delay time of the decided interference wave.
    Type: Application
    Filed: February 16, 2011
    Publication date: August 18, 2011
    Applicant: FUJITSU LIMITED
    Inventors: Masataka UMEDA, Takanori Iwamatsu
  • Publication number: 20110078531
    Abstract: A radio communication apparatus for performing radio communicate with other radio communication apparatus, the radio communication apparatus including: a quality measuring unit which measures reception quality of reception signal which is received from the other radio communication apparatus; a first error detecting unit which detects an error of reception data included in the reception signal on the basis of the reception quality and a first threshold value; and a retransmission request signal generating unit which generates a retransmission request signal on the basis of an error detection result of the first error detection unit, and transmits the retransmission request signal to the other radio communication apparatus.
    Type: Application
    Filed: September 29, 2010
    Publication date: March 31, 2011
    Applicant: FUJITSU LIMITED
    Inventors: Masataka UMEDA, Naoyuki Saitou
  • Publication number: 20110019606
    Abstract: Each mobile terminal apparatus measures receiving power or receiving quality of a signal received from a radio communication apparatus. If a plurality of mobile terminal apparatuses in which the receiving power or the receiving quality is lower than or equal to a determined threshold are detected, then a communication control apparatus selects a mobile terminal apparatus made to function as a relay station from the plurality of mobile terminal apparatuses detected on the basis of a result of measuring the receiving power or the receiving quality. The mobile terminal apparatus selected relays communication between the radio communication apparatus and a mobile terminal apparatus which does not function as a relay station.
    Type: Application
    Filed: June 30, 2010
    Publication date: January 27, 2011
    Applicant: FUJITSU LIMITED
    Inventors: Masataka UMEDA, Yoshiyuki Oota
  • Publication number: 20100173663
    Abstract: A radio communication apparatus, for use as a base station, includes a receiver configured to receive a signal in a predetermined radio frequency band transmitted from a terminal under control of another radio communication apparatus adjacent to the radio communication apparatus and detecting a receiving condition of the signal and a notifying unit configured to notify the receiving condition to an apparatus performing transmission power control of the signal in the predetermined radio frequency band transmitted from the terminal.
    Type: Application
    Filed: December 31, 2009
    Publication date: July 8, 2010
    Applicant: FUJITSU LIMITED
    Inventor: Masataka UMEDA
  • Publication number: 20090296651
    Abstract: A data allocation method in a wireless communication system in which data is allocated in both a time axis direction and frequency axis direction, and data is transmitted between a mobile station and base station according to an allocated schedule, the allocation method including: measuring propagation path information between the mobile station and the base station; and modifying an allocation width of a burst in the time axis direction or in the frequency axis direction based on the propagation path information.
    Type: Application
    Filed: August 12, 2009
    Publication date: December 3, 2009
    Inventors: Masataka UMEDA, Hideki Furudate
  • Publication number: 20090186621
    Abstract: A radio base station for performing communication through three or more frequency bands based on orthogonal frequency division multiplexing includes a transmission unit configured to transmit a first channel through at least one of the three or more frequency bands and to transmit a second channel having smaller power than the first channel through at least another one of the three or more frequency bands, the first channel and the second channel being transmittable concurrently in time, a reception condition detecting unit configured to detect a reception condition of one or more mobile stations residing within a local cell, and a scheduling unit configured to select one of the first channel and the second channel, a modulation scheme, and a transmission power to be used for at least a downlink to one of the mobile stations based on the detected reception condition.
    Type: Application
    Filed: August 28, 2008
    Publication date: July 23, 2009
    Applicant: FUJITSU LIMITED
    Inventors: Masataka UMEDA, Hiromu MATSUZAWA