Patents by Inventor Yasuyuki Oishi

Yasuyuki Oishi 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: 20050047521
    Abstract: A distortion compensating apparatus calculates a distortion compensation coefficient in such a manner that a difference signal between a reference signal, which is a transmit signal, and a feedback signal will be diminished, updates an old distortion compensation coefficient by the calculated distortion compensation coefficient and applies distortion compensation to the transmit signal based upon this distortion compensation coefficient. In this apparatus, a phase correcting interval, which is for correcting the phase difference between the reference signal and the feedback signal, and a distortion compensation coefficient updating interval are generated alternately, a correction is applied so as to null the phase difference in the phase correcting interval, and the distortion compensation coefficient is updated in the distortion compensation coefficient updating interval.
    Type: Application
    Filed: September 22, 2004
    Publication date: March 3, 2005
    Inventors: Hiroyoshi Ishikawa, Tokuro Kubo, Kazuo Nagatani, Yasuyuki Oishi, Hajime Hamada, Nobukazu Fudaba, Toru Maniwa, Hiroyuki Hayashi
  • Patent number: 6853631
    Abstract: A phase ?I1, . . . , ?Q1, . . . uniquely determined for each channel is assigned to a carrier for each channel used when data I1 . . . , Q1, . . . , to be distributed among different channels are modulated. By appropriately modifying the phase of a carrier for each channel, signal points can be located in a narrower region than in a conventional region, and thereby the difference in amplitude between a signal point with a minimum amplitude and a signal point with a maximum amplitude can be reduced. Thus, the amplitude range of a signal to be covered by an amplifier for transmitting a transmission signal is reduced, and thereby an amplifier with a linearity that is not high can be used for the amplifier. Accordingly, even if the number of signal points increase, there is no need to use a large high-power amplifier, and thereby the small power and small size of the apparatus can be realized.
    Type: Grant
    Filed: October 12, 1999
    Date of Patent: February 8, 2005
    Assignee: Fujitsu Limited
    Inventors: Michiharu Nakamura, Hajime Hamada, Yasuyuki Oishi, Kazuo Nagatani
  • Publication number: 20050020310
    Abstract: A MIMO wireless communication system and wireless communication apparatuses are disclosed that increase the practically usable communication channel capacity in the Shannon channel capacity that determines the ratio of maximum signal transmission speed to frequency. Each wireless communication apparatus includes antenna units that transmit and receive radio frequency signals, and a weight controlling unit that provides weights with respect to the antenna units. The antenna units are formed by adaptive array antenna units that can change the directivity by varying weights with respect to antenna elements.
    Type: Application
    Filed: March 16, 2004
    Publication date: January 27, 2005
    Inventors: Yuuta Nakaya, Takeshi Toda, Yasuyuki Oishi, Kaoru Yokoo
  • Publication number: 20040266354
    Abstract: Disclosed is a method of controlling direction of radio-wave emission of a base-station transmitter which emits radio waves upon providing the radio waves with directivity in the direction of a receiver. Two antennas of a base station that are disposed at different positions transmit first and second signals that have been spread by mutually orthogonal spreading codes. A mobile station has a phase detector for receiving the first and second signals transmitted from respective ones of the antennas and obtaining a phase difference between these signals, and a direction estimator for calculating the direction of the mobile station, as seen from the base station, based upon the phase difference and for feeding back a signal representing the calculated direction from the mobile station to the base station. The transmitter of the base station transmits data toward the receiver in the calculated direction using a directional antenna.
    Type: Application
    Filed: June 3, 2004
    Publication date: December 30, 2004
    Inventors: Hajime Hamada, Michiharu Nakamura, Yasuyuki Oishi
  • Patent number: 6836517
    Abstract: A distortion compensating apparatus for compensating for a distortion of a transmission power amplifier. A delay time decision unit calculates the correlation between a transmission signal and a feedback signal fed back from the output side of the transmission power amplifier while varying phase difference between both signals, and decides the total delay time caused in the transmission power amplifier and a feedback loop on the basis of the phase difference in which the correlation is the maximum. A delay unit delays the transmission signal before a distortion compensation processing by the total delay time, and inputs the delayed signal into a distortion compensating apparatus arithmetic unit, which calculates and stores a distortion compensation coefficient on the basis of the transmission signal and the feedback signal fed back from the output side of the transmission power amplifier.
    Type: Grant
    Filed: December 22, 2000
    Date of Patent: December 28, 2004
    Assignee: Fujitsu Limited
    Inventors: Kazuo Nagatani, Tokuro Kubo, Takayoshi Ode, Yasuyuki Oishi
  • Publication number: 20040258138
    Abstract: The present invention reduces the scale of circuitry and shortens the code phase detection time needed to achieve initial synchronization. In a correlator for calculating correlation between a received spreading code contained in a received spread-spectrum signal and a reference spreading code, a combined code generator is included. The combined code generator outputs a combined spreading code by weighting and combining a plurality of phase-shifted reference spreading codes A1-AM. Further, an arithmetic circuit calculates correlation between the received spreading code and the plurality of phase-shifted reference spreading codes simultaneously. A phase detection circuit detects the phase difference between the received spreading code and a reference spreading code, namely the phase of the received spreading code from the results of the arithmetic operation.
    Type: Application
    Filed: July 22, 2003
    Publication date: December 23, 2004
    Inventors: Yasuyuki Oishi, Kazuo Nagatani, Hajime Hamada, Yoshihiko Asano
  • Publication number: 20040239436
    Abstract: An adaptive controller adaptively controls a plurality of variable high frequency devices. A calculation part calculates a scalar function value by using a signal varied in accordance with impedances of the variable high frequency devices, a reference signal, and a predetermined scalar function. An impedance variation part creates a signal that sequentially varies the impedances of the variable high frequency devices. A determination part determines, when the impedance of one of the variable high frequency devices is varied, whether a direction in which the scalar function value is varied is in a predetermined sloped direction. The impedance variation part includes a first variation part that, when a decision result in the determination part is in the predetermined direction, creates a signal that further varies the impedance of the one of the variable high frequency devices in the predetermined sloped direction.
    Type: Application
    Filed: March 18, 2004
    Publication date: December 2, 2004
    Inventors: Takeshi Toda, Yuuta Nakaya, Yasuyuki Oishi, Kaoru Yokoo, Shinsuke Hara, Yuji Irie
  • Patent number: 6826169
    Abstract: A code multiplexing transmitting apparatus spread-spectrum modulates transmission data of a plurality of channels by spreading codes that differ from one another, combines the spread-spectrum signals of each of the channels and transmits the resultant spread-spectrum modulated signal. A spread-spectrum modulating unit for each channel includes a phase shifter for shifting, by a predetermined angle channel by channel, the phase of a position vector of the spread-spectrum modulated signal of each channel. As the result of such phase control, the phases of pilot signal portions of the spread-spectrum modulated signals of the respective channels are shifted relative to one another so that the peak values of the code-multiplexed signal can be suppressed.
    Type: Grant
    Filed: July 13, 2000
    Date of Patent: November 30, 2004
    Assignee: Fujitsu Limited
    Inventors: Kazuo Nagatani, Yasuyuki Oishi, Hidenobu Fukumasa, Hajime Hamada, Yoshihiko Asano
  • Publication number: 20040212428
    Abstract: In a distortion compensation device which uses distortion compensation coefficients to subject distortion compensation processing to an input signal and supply the result of the distortion compensation processing to a distorting device, calculates the distortion compensation coefficients based on the input signal before distortion compensation and the feedback signal fed back from the output side of the distorting device, and stores the calculated distortion compensation coefficients in association with the input signal, (1) the feedback signal is AD-converted; (2) the AD-converted output is subjected to fast Fourier transform (FFT) processing; (3) the FFT calculation result is used to calculate the value of either the signal-to-noise ratio SNR, or the adjacent channel leakage power ratio ACLR, or the noise level; (4) the delay time occurring in the distorting device and feedback loop is adjusted such that the difference between the above calculated value at the current time and the above calculated value at
    Type: Application
    Filed: October 15, 2003
    Publication date: October 28, 2004
    Inventors: Takayoshi Ode, Yasuyuki Oishi, Tokuro Kubo, Kazuo Nagatani, Hajime Hamada, Hiroyoshi Ishikawa, Nobukazu Fudaba
  • Publication number: 20040198393
    Abstract: Disclosed is a method of controlling direction of radio-wave emission of a base-station transmitter which emits radio waves upon providing the radio waves with directivity in the direction of a receiver. Two antennas of a base station that are disposed at different positions transmit first and second signals that have been spread by mutually orthogonal spreading codes. A mobile station has a phase detector for receiving the first and second signals transmitted from respective ones of the antennas and obtaining a phase difference between these signals, and a direction estimator for calculating the direction of the mobile station, as seen from the base station, based upon the phase difference and for feeding back a signal representing the calculated direction from the mobile station to the base station. The transmitter of the base station transmits data toward the receiver in the calculated direction using a directional antenna.
    Type: Application
    Filed: April 20, 2004
    Publication date: October 7, 2004
    Inventors: Hajime Hamada, Michiharu Nakamura, Yasuyuki Oishi
  • Publication number: 20040192394
    Abstract: A method of controlling an array antenna part having a plurality of antenna elements arranged at a predetermined interval, includes the steps of obtaining a predetermined evaluation function with respect to each of weighting coefficients to be applied to incoming signals arriving at a predetermined number of antenna elements, by perturbing each of the weighting coefficients at a sampling interval which is within one symbol time, and adjusting each of the weighting coefficients based on the evaluation function.
    Type: Application
    Filed: January 14, 2004
    Publication date: September 30, 2004
    Inventors: Yuuta Nakaya, Takeshi Toda, Yasuyuki Oishi
  • Patent number: 6791965
    Abstract: A code multiplexing transmitting apparatus spread-spectrum modulates transmission data of a plurality of channels by spreading codes that differ from one another, combines the spread-spectrum signals of each of the channels and transmits the resultant spread-spectrum modulated signal. A spread-spectrum modulating unit for each channel includes a phase shifter for shifting, by a predetermined angle channel by channel, the phase of a position vector of the spread-spectrum modulated signal of each channel. As the result of such phase control, the phases of pilot signal portions of the spread-spectrum modulated signals of the respective channels are shifted relative to one another so that the peak values of the code-multiplexed signal can be suppressed.
    Type: Grant
    Filed: October 17, 2002
    Date of Patent: September 14, 2004
    Assignee: Fujitsu Limited
    Inventors: Kazuo Nagatani, Yasuyuki Oishi, Hidenobu Fukumasa, Hajime Hamada, Yoshihiko Asano
  • Publication number: 20040169602
    Abstract: Disclosed is a method of controlling direction of radio-wave emission of a base-station transmitter which emits radio waves upon providing the radio waves with directivity in the direction of a receiver. Two antennas of a base station that are disposed at different positions transmit first and second signals that have been spread by mutually orthogonal spreading codes. A mobile station has a phase detector for receiving the first and second signals transmitted from respective ones of the antennas and obtaining a phase difference between these signals, and a direction estimator for calculating the direction of the mobile station, as seen from the base station, based upon the phase difference and for feeding back a signal representing the calculated direction from the mobile station to the base station. The transmitter of the base station transmits data toward the receiver in the calculated direction using a directional antenna.
    Type: Application
    Filed: March 11, 2004
    Publication date: September 2, 2004
    Inventors: Hajime Hamada, Michiharu Nakamura, Yasuyuki Oishi
  • Publication number: 20040139897
    Abstract: A communications apparatus using an adaptive antenna having in a high frequency unit an antenna unit including a plurality of antenna elements and a plurality of adjustment units, provided corresponding to the plurality of antenna elements, for adjusting directivity of an entire antenna, comprising:
    Type: Application
    Filed: January 9, 2004
    Publication date: July 22, 2004
    Inventors: Yuta Nakaya, Takeshi Toda, Yasuyuki Oishi, Shinsuke Hara
  • Patent number: 6757525
    Abstract: In an adaptive predistorter type distortion compensating apparatus for calculating a distortion compensating coefficient by using an adaptive algorithm so as to reduce an error between a reference signal and a feedback signal of a circuit which generates a distortion on the basis of the reference signal, and for compensating the distortion by providing the distortion compensating coefficient to the reference signal, a phase adjustment circuit is provided for determining a phase shift value which reduces a phase difference between a reference signal and a feedback signal, for correcting the phase of the reference signal or the feedback signal by the phase shift value, and for calculating the distortion compensating apparatus after the correction.
    Type: Grant
    Filed: October 25, 2002
    Date of Patent: June 29, 2004
    Assignee: Fujitsu Limited
    Inventors: Hiroyoshi Ishikawa, Kazuo Nagatani, Yasuyuki Oishi, Tokuro Kubo, Hajime Hamada, Nobukazu Fudaba, Mitsuharu Hamano, Tohru Sasaki, Yuki Kanno, Koichi Hanada
  • Patent number: 6737918
    Abstract: An input complex base band signal x(t) is complex-multiplied by a distortion compensation coefficient h(p), quadrature-modulated by a quadrature modulator QMOD, and input into a power amplifier AMP. A part of the output from the power amplifier AMP is input into a band pass filter BPF, the band pass filter BPF extracts an adjacent channel leakage power band, and a power detector detects an adjacent channel leakage power value. A distortion compensation coefficient arithmetic unit GA using a genetic algorithm computes a distortion compensation coefficient based on an adjacent channel leakage power value on an adjacent channel leakage power ratio and an input complex base band signal x(t), and outputs a distortion compensation coefficient h(p) as a function of a power value p of the input complex base band signal.
    Type: Grant
    Filed: July 29, 2003
    Date of Patent: May 18, 2004
    Assignee: Fujitsu Limited
    Inventors: Yasuyuki Oishi, Tokuro Kubo, Kazuo Nagatani, Toru Maniwa
  • Patent number: 6717464
    Abstract: In a distortion compensating apparatus for adaptively compensating a non-linear distortion of a circuit having the non-linear distortion, an adaptive equalizing processor adaptively selects, from among a filter coefficient group preliminarily held in a memory, a filter coefficient which makes an out-of-band power of an output signal reduced to be set in a digital filter.
    Type: Grant
    Filed: September 27, 2002
    Date of Patent: April 6, 2004
    Assignee: Fujitsu Limited
    Inventors: Nobukazu Fudaba, Yasuyuki Oishi, Tokuro Kubo, Kazuo Nagatani, Hajime Hamada, Hiroyoshi Ishikawa
  • Publication number: 20040021516
    Abstract: An input complex base band signal x(t) is complex-multiplied by a distortion compensation coefficient h(p), quadrature-modulated by a quadrature modulator QMOD, and input into a power amplifier AMP. A part of the output from the power amplifier AMP is input into a band pass filter BPF, the band pass filter BPF extracts an adjacent channel leakage power band, and a power detector detects an adjacent channel leakage power value. A distortion compensation coefficient arithmetic unit GA using a genetic algorithm computes a distortion compensation coefficient based on an adjacent channel leakage power value or an adjacent channel leakage power ratio and an input complex base band signal x(t), and outputs a distortion compensation coefficient h(p) as a function of a power value p of the input complex base band signal.
    Type: Application
    Filed: July 29, 2003
    Publication date: February 5, 2004
    Inventors: Yasuyuki Oishi, Tokuro Kubo, Kazuo Nagatani, Toru Maniwa
  • Publication number: 20040013705
    Abstract: An object of this invention is to provide new processed meat foods that can fortify the physical endurance significantly or promote the combustion of body fats.
    Type: Application
    Filed: March 25, 2003
    Publication date: January 22, 2004
    Inventors: Itaru Watanabe, Yasuyuki Oishi, Hironori Tomi
  • Publication number: 20040014433
    Abstract: Disclosed is a method of controlling direction of radio-wave emission of a base-station transmitter which emits radio waves upon providing the radio waves with directivity in the direction of a receiver. Two antennas of a base station that are disposed at different positions transmit first and second signals that have been spread by mutually orthogonal spreading codes. A mobile station has a phase detector for receiving the first and second signals transmitted from respective ones of the antennas and obtaining a phase difference between these signals, and a direction estimator for calculating the direction of the mobile station, as seen from the base station, based upon the phase difference and for feeding back a signal representing the calculated direction from the mobile station to the base station. The transmitter of the base station transmits data toward the receiver in the calculated direction using a directional antenna.
    Type: Application
    Filed: April 14, 2003
    Publication date: January 22, 2004
    Inventors: Hajime Hamada, Michiharu Nakamura, Yasuyuki Oishi