Patents by Inventor Koji Akita

Koji Akita 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: 20090239482
    Abstract: A radio communication apparatus includes a first acquisition unit configured to acquire a first frequency use status of a first frequency band having a first center frequency, a second acquisition unit configured to acquire a second frequency use status of a second frequency band having a second center frequency which is a value M/N times (M and N are natural numbers, and M?N) of the first center frequency, and a decision unit configured to determine whether a harmonic is detected in the first frequency band using the first frequency use status and the second frequency use status, and to decide, if it is determined that the harmonic is detected, a radio communication parameter in the first frequency band so as to use a frequency band used by the harmonic in radio communication.
    Type: Application
    Filed: March 2, 2009
    Publication date: September 24, 2009
    Inventors: Koji Akita, Tazuko Tomioka
  • Publication number: 20090147875
    Abstract: A radio transmitter includes a unit which generates a first instruction to instruct the transmission of a first transmission signal, a unit which generates the first transmission signal based on the first instruction, a unit which generates a second instruction to instruct the transmission of a second transmission signal to be selectively multiplied by an orthogonal code, a unit which generates the second transmission signal based on the second instruction, unit which transmits the first and the second transmission signals, a unit which predicts a collision of the first and second transmission signals, and a unit which stops the first transmission signal while the collision is predicted in a case where the second transmission signal is multiplied by the orthogonal code and which stops the second transmission signal while the collision is predicted in a case where the second transmission signal is not multiplied by the orthogonal code.
    Type: Application
    Filed: February 10, 2009
    Publication date: June 11, 2009
    Inventors: Koji Akita, Kaoru Inoue, Ren Sakata
  • Patent number: 7447271
    Abstract: Radio receiving apparatus includes antennas, radio units adjusting gains of received signals, and outputting the adjusted received signals, respectively, converters converting the adjusted received signals into digital signals, selector device which selects several of the digital signals, combination of the selected digital signals exhibiting good receiving characteristic, controller which determines the gains and outputs single control signal included in information of the determined gains to certain radio units, the certain radio units being included in the radio units and connected to certain converters of the converters which output digital signals included in the selected combination, weight calculator which calculates weight for each of the selected digital signals to enhance the receiving characteristic if the controller outputs the single control signal, synthesizer which synthesizes, into synthetic digital signal, digital signals obtained by multiplying each of the selected digital signals by the wei
    Type: Grant
    Filed: October 31, 2007
    Date of Patent: November 4, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koji Akita, Kazumi Sato, Kuniaki Ito, Akihiro Tsujimura
  • Publication number: 20080240273
    Abstract: A radio transmitting apparatus includes an attacher to attach an error-detecting bit to a bit sequence, a coder to perform systematic coding on a bit sequence to which the error-detecting bit is attached to generate an information bit sequence and a parity bit sequence, a first modulator to modulate the information bit sequence to generate a first modulation symbol, a second modulator to modulate the parity bit sequence to generate a second modulation symbol, an allocator to allocate the first modulation symbols to first subcarriers by dispersing the first modulation symbols in the frequency/time direction, and allocate the second modulation symbols to second subcarriers different from the first subcarriers, an modulator to perform OFDM modulation on the first and second modulation symbols by using the first and the second subcarriers to generate an OFDM signal, and a transmitting unit to transmit the OFDM signal.
    Type: Application
    Filed: March 17, 2008
    Publication date: October 2, 2008
    Inventor: Koji AKITA
  • Publication number: 20080242233
    Abstract: A radio transmitting apparatus includes a storage unit configured to store a plurality of weight sequence sets, which are each assigned to a plurality of transmission blocks sectioned by time axes and frequency axes, by associating the plurality of weight sequence sets with the plurality of transmission blocks, a first selecting unit configured to select one transmission block from the plurality of transmission blocks, a second selecting unit configured to select one weight sequence from one weight sequence set assigned to the one transmission block signal, a converting unit configured to convert a data signal by using the one weight sequence to generate a converted signal, and a transmitting unit configured to transmit the converted signal by using the one transmission block.
    Type: Application
    Filed: March 18, 2008
    Publication date: October 2, 2008
    Inventors: Koji AKITA, Noritaka DEGUCHI, Ren SAKATA, Koichiro BAN
  • Publication number: 20080227389
    Abstract: A radio communication method including, generating a first transmit RF signal and a second transmit RF signal from a data signal to be transmitted, each of the first and second transmit RF signals having a power spectrum in symmetric shape in the frequency domain, transmitting the first transmit RF signal and the second transmit RF signal at a different time, receiving the first transmit RF signal and the second transmit RF signal to generate a first received RF signal and a second received RF signal, and reproducing the data signal from the first received RF signal and the second received RF signal.
    Type: Application
    Filed: September 12, 2007
    Publication date: September 18, 2008
    Inventors: Ren Sakata, Koji Akita, Koichiro Ban, Noritaka Deguchi
  • Patent number: 7362956
    Abstract: An apparatus is capable of playing back video content recorded on a DVD-Video disk without requiring the playing of a menu. A presentation sequence control unit of a non-video navigation manager extracts button commands for playing titles from a VMGM-PG for displaying a title menu defined for a DVD-Video disk. The presentation sequence control unit selects the extracted button commands in a predetermined order and requests a navigation control unit to play titles indicated by the button commands. The navigation control unit controls a presentation engine to reproduce audio data of the titles in accordance with VTS-PGCs for playing back titles and to provide the reproduced audio data through an audio output device.
    Type: Grant
    Filed: March 20, 2003
    Date of Patent: April 22, 2008
    Assignee: Alpine Electronics, Inc.
    Inventors: Koji Akita, Tetsuya Kishi
  • Patent number: 7359627
    Abstract: A DVD player performs processing which, when subpicture settings, audio settings, or angle settings cannot be changed, determines whether the switching operation is impossible due to a lack of data recorded on a DVD, or is prohibited by a title producer or due to player specifications. When a user-designated operation cannot be executed, the DVD player displays a message indicating that the operation is prohibited by the title producer or due to the player specifications. When the operation is impossible due to a lack of data corresponding to the operation, the DVD player displays a message indicating that the operation is impossible due to the lack of the corresponding data.
    Type: Grant
    Filed: April 15, 2002
    Date of Patent: April 15, 2008
    Assignee: Alpine Electronics, Inc.
    Inventors: Koji Akita, Hideki Ito
  • Publication number: 20080063108
    Abstract: Radio receiving apparatus comprises antennas, radio units adjusting gains of received signals, and outputting the adjusted received signals, respectively, converters converting the adjusted received signals into digital signals, selector device which selects several of the digital signals, combination of the selected digital signals exhibiting good receiving characteristic, controller which determines the gains and outputs single control signal included in information of the determined gains to certain radio units, the certain radio units being included in the radio units and connected to certain converters of the converters which output digital signals included in the selected combination, weight calculator which calculates weight for each of the selected digital signals to enhance the receiving characteristic if the controller outputs the single control signal, synthesizer which synthesizes, into synthetic digital signal, digital signals obtained by multiplying each of the selected digital signals by the we
    Type: Application
    Filed: October 31, 2007
    Publication date: March 13, 2008
    Inventors: Koji AKITA, Kazumi SATO, Kuniaki ITO, Akihiro TSUJIMURA
  • Publication number: 20080037686
    Abstract: A wireless transmitter includes an allocation unit allocating first modulation symbols to first subcarriers arranged in N subcarriers cycles, modulators performing OFDM modulation on the first modulation symbols allocated to the first subcarriers to generate OFDM signals including at least one OFDM symbol corresponding to the first modulation symbol, a cyclic delayer performing cyclic delay on the OFDM symbol in the delay amount corresponding to d/N times the symbol length, and transmission units transmitting the OFDM signals.
    Type: Application
    Filed: August 14, 2007
    Publication date: February 14, 2008
    Inventors: Koji AKITA, Noritaka Deguchi
  • Publication number: 20080037680
    Abstract: A transmitter includes first generator to generate pilot source signal by modulating pilot sequence, second generator to generate data source signal with time length longer than that of pilot source signal by modulating data sequence, first cyclic shifter to perform cyclic shift of first shift amount to pilot source signal to generate first pilot signal, second cyclic shifter to performs cyclic shift of second shift amount to data source signal to generate first data signal, third cyclic shifter to perform cyclic shift of third shift amount to pilot source signal to generate second pilot signal, fourth cyclic shifter to perform cyclic shift of fourth shift amount to data source signal to generate second data signal, first transmit antenna to transmit first pilot signal and first data signal, and second transmit antenna to transmit second pilot signal and second data signal.
    Type: Application
    Filed: August 14, 2007
    Publication date: February 14, 2008
    Inventors: Ren SAKATA, Koji Akita
  • Patent number: 7308037
    Abstract: Radio receiving apparatus includes antennas, radio units adjusting gains of received signals, and outputting the adjusted received signals, respectively, converters converting the adjusted received signals into digital signals, selector device which selects several of the digital signals, combination of the selected digital signals exhibiting good receiving characteristic, controller which determines the gains and outputs single control signal included in information of the determined gains to certain radio units, the certain radio units being included in the radio units and connected to certain converters of the converters which output digital signals included in the selected combination, weight calculator which calculates weight for each of the selected digital signals to enhance the receiving characteristic if the controller outputs the single control signal, synthesizer which synthesizes, into synthetic digital signal, digital signals obtained by multiplying each of the selected digital signals by the wei
    Type: Grant
    Filed: September 28, 2004
    Date of Patent: December 11, 2007
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koji Akita, Kazumi Sato, Kuniaki Ito, Akihiro Tsujimura
  • Publication number: 20070258357
    Abstract: A method of transmitting OFDM signals including, allocating a first pilot signal and a first data signal which are both common among OFDM transmitters respectively to at least one first pilot subcarrier and first data subcarriers within a specific time-frequency domain that is common among the OFDM transmitters and different among wireless transmitting units, allocating a second pilot signal and a second data signal respectively to second pilot subcarrier and second data subcarriers outside the time-frequency domain, multiplying the first pilot signal and the first data signal by a complex number set for the time-frequency domain, generating an OFDM signal by performing OFDM modulation on the first pilot signal and the first data signal multiplied by the complex number and the second pilot signal and the second data signal, and transmitting the OFDM signal.
    Type: Application
    Filed: July 12, 2007
    Publication date: November 8, 2007
    Inventor: Koji Akita
  • Publication number: 20070253321
    Abstract: An OFDM transmitter includes, a data signal generator which generates a data signal by modulating a bit string obtained by channel coding, a pilot signal generator which generates a pilot signal, an allocation unit which allocates the pilot signal and data signal to a pilot subcarrier and a data subcarrier, a multiplier which multiples the first pilot signal and the first data signal by complex numbers for subcarrier group formed of specific pilot subcarrier of the pilot subcarriers and specific data subcarrier of the data subcarriers, a modulator which performs OFDM modulation on the second pilot signal and the second data signal to generate an OFDM signal, and a transmitting unit which transmits the OFDM signal.
    Type: Application
    Filed: July 12, 2007
    Publication date: November 1, 2007
    Inventors: Koji AKITA, Noritaka Deguchi
  • Patent number: 7283598
    Abstract: An OFDM receiver apparatus comprises a receiver to receive an OFDM signal, an estimator to estimate a distortion, a distortion compensator subjecting the sub-carrier to distortion compensation according to a control signal to generate a distortion-compensated sub-carrier, a demodulator to demodulate the distortion-compensated sub-carrier, an estimator to generate first phase distortion information, using the distortion-compensated sub-carrier and the distortion information, a weighting synthesizer to weight the first phase distortion information by weighting factors with time function over symbol intervals and then synthesize the first phase distortion information, to generate second phase distortion information, and a control signal generator to generate the control signal using the distortion information and the second phase distortion information.
    Type: Grant
    Filed: March 31, 2004
    Date of Patent: October 16, 2007
    Inventors: Koji Akita, Kazumi Sato, Ren Sakata
  • Publication number: 20070165514
    Abstract: An OFDM transmitter includes, an allocation unit configured to allocate a first pilot signal and a first data signal respectively to at least one first pilot subcarrier and first data subcarriers within a subcarrier group that is identical among transmitters, and to allocate a second pilot signal and a second data signal respectively to at least one second pilot subcarrier and second data subcarriers outside the subcarrier group, a multiplier to multiply the first pilot signal and the first data signal by complex numbers set for the subcarriers, a modulator to subject the first pilot signal and the first data signal multiplied by the complex numbers and the second pilot signal and the second data signal to OFDM modulation in order to generate an OFDM signal, and a transmission unit configured to transmit the generated OFDM signal.
    Type: Application
    Filed: January 3, 2007
    Publication date: July 19, 2007
    Inventor: Koji Akita
  • Patent number: 7239803
    Abstract: A DVD-video playback apparatus including a navigation manager that estimates the size of each title included in a DVD disc when the navigation manager receives a playback start command for the DVD disc from a main controller. The navigation manager sets titles whose sizes are larger than half of the size of the largest title as monitored titles, and starts playing back the DVD discs 1 by controlling a presentation engine. When the playback of all of the monitored titles is completed, the playback is stopped and a disc-change request is issued to the main controller. The main controller changes the DVD disc to another DVD disc by controlling a DVD changer, and issues a playback start command for the new DVD disc to the navigation manager.
    Type: Grant
    Filed: May 13, 2003
    Date of Patent: July 3, 2007
    Assignee: Alpine Electronics, Inc.
    Inventor: Koji Akita
  • Publication number: 20070147523
    Abstract: A radio communication system includes a first radio communication apparatus comprising a data generating unit generating transmit data, a mapping unit allocating a modulation signal generated according to the transmit data to two subcarriers between which a frequency difference of a first frequency is, an IFFT unit performing IFFT on the modulation signal allocated to each subcarrier to generate an OFDM signal having a second frequency higher than the first frequency, and a transmitter transmitting a radio frequency signal obtained from the OFDM signal, and a second radio communication apparatus comprising a receiver downconverting the radio frequency signal into a baseband signal, an AD converter sampling the baseband signal at the first frequency, a FFT unit performing FFT on an output of the AD converter to extract a receive signal, and a data demapping unit demapping the receive signal to obtain receive data.
    Type: Application
    Filed: September 19, 2006
    Publication date: June 28, 2007
    Inventors: Ren Sakata, Koji Akita
  • Publication number: 20070098096
    Abstract: A wireless transmitter for transmitting an OFDM symbol including a first generator to generate a plurality of first signals each including a stationary signal, a second generator to generate a plurality of second signals whose total power is less than that of the first signals, and an allocation unit configured to allocate the first signals to the ±N*k (N: an integral number not less than or equal to 2, k=1, 2, . . . ) th first subcarriers of a synchronizing symbol and to allocate the second signals to at least some second subcarriers of the synchronizing symbol, a generating unit configured to generates a signal of an OFDM symbol including the synchronizing symbol in which the first signals and the second signals are allocated into the first subcarriers and the second subcarriers, and a transmission unit configured to transmit the signal of the OFDM symbol.
    Type: Application
    Filed: October 11, 2006
    Publication date: May 3, 2007
    Inventors: Koji AKITA, Koichiro Ban
  • Publication number: 20060203759
    Abstract: A modulator includes a first input configured to input a first bit string; a first modulating device configured to modulate the inputted first bit string at a first bit rate; a second input configured to input a second bit string; a second modulating device configured to modulate the inputted second bit string at a second bit rate which is lower than the first bit rate; and an output configured to output a modulated signal including the modulated first bit string and the modulated second bit string.
    Type: Application
    Filed: February 24, 2006
    Publication date: September 14, 2006
    Inventors: Koji Akita, Tomoya Horiguchi, Koji Ogura