Patents by Inventor Katsuhiko Tsunehara

Katsuhiko Tsunehara 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: 20160057674
    Abstract: The invention is intended to, even in a situation where there are many candidate wireless base stations (WBSs) to which a mobile terminal (MT) may connect, get information of communication conditions between the MT and each of those WBSs and determine an WBS to which the MT should connect in a shorter time. A coverage area of the first WBS is overlapped partially at least by a coverage area of the second WBS. The MT transmits a signal for connection using a predetermined frequency. Upon receiving the signal for connection, the second WBSs each notify the WBS communication manager of their reception results of the signal for connection. The WBS communication manager selects a second WBS to communicate with the MT based on the reception results and notifies the selected second WBS to transmit a response signal to the signal for connection to the MT.
    Type: Application
    Filed: March 15, 2013
    Publication date: February 25, 2016
    Inventors: Eriko TAKEDA, Takashi ISHIKAWA, Satoshi TAMAKI, Go ONO, Katsuhiko TSUNEHARA, Kenzaburo FUJISHIMA
  • Patent number: 8891390
    Abstract: Provided is a wireless communication system which includes a wireless communication unit using plural frequency bands and plural antennas. The system changes the transmission power of each antenna, based on the interference of each of the frequency bands from the neighbor base station along the antenna direction. The system estimates the number of antennas necessary for transmission in response to a user requirement, and determines a necessary antenna in accordance with the antenna direction in which the terminal is located, and further changes the transmission power of each antenna.
    Type: Grant
    Filed: December 1, 2011
    Date of Patent: November 18, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Hajime Kanzaki, Kenzaburo Fujishima, Mikio Kuwahara, Katsuhiko Tsunehara
  • Patent number: 8787146
    Abstract: A discontinuous change in a transmission timing in a time domain, which is caused by a transmission timing adjustment processing of an OFDMA uplink or the like, brings about a discontinuous rotation of a signal phase in a frequency domain, resulting in reduced communication quality. A wireless communication system of the present invention allows the signal phase of the frequency domain in a receiving station to be continuous before and after the timing adjustment processings by controlling a signal sequence in a transmission signal after conversion in the time domain in synchronization with the timing adjustment processing.
    Type: Grant
    Filed: February 16, 2009
    Date of Patent: July 22, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Satoshi Tamaki, Mikio Kuwahara, Kenzaburo Fujishima, Pinai Linwong, Katsuhiko Tsunehara
  • Patent number: 8451774
    Abstract: To control the communication quality on the terminal basis without making the base station more complicated, it is provided a communication system, comprising at least one computer and a gateway that is connected to the at least one computer through a first network. The gateway is connected to at least one terminal through a second network. The at least one terminal performs communications with the at least one computer via the gateway. The gateway estimates quality of the communications between the gateway and the at least one computer in the first network; and determines a priority for the communications between the gateway and the at least one terminal in the second network according to the estimated quality of the communications in the first network.
    Type: Grant
    Filed: December 8, 2009
    Date of Patent: May 28, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Katsuhiko Tsunehara, Daisuke Matsubara, Seishi Hanaoka, Masashi Yano
  • Patent number: 8447311
    Abstract: A radio communications system includes at least one terminal communication unit having one antenna that conducts a radio communication with a plurality of terminals; and at least one baseband modem that generates and decrypts a data signal, a cell being configured by at least one of the antenna, wherein the baseband modem divides a radio frequency band used for the radio communication into two or more subbands, generates and decrypts the data signal specific to each of the divided subbands, and allocates the data signal specific to the subband to the terminal communication unit, and wherein the terminal communication unit receives the data signal specific to the subband generated by the baseband modem, and forms the cell of each the subband by the data signal specific to the received subband.
    Type: Grant
    Filed: February 23, 2010
    Date of Patent: May 21, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Kenzaburo Fujishima, May Takada, Katsuhiko Tsunehara, Satoshi Tamaki, Shinya Sasaki, Go Ono, Koki Uwano
  • Patent number: 8413030
    Abstract: The error correction capability for wireless communication carried out involving propagation path fluctuation in time and frequency selectivity can be improved. A soft decision likelihood value inputted to an error correction decoder is multiplied by a weight determined according to the distance between the data symbol and pilot symbol corresponding to the soft decision likelihood value. Namely, the soft decision bit likelihood value corresponding to the data symbol is weighted according to the distances in time or frequency between the pilot symbol and data symbol. The weight is made smaller when the distance in time or frequency is larger.
    Type: Grant
    Filed: May 28, 2009
    Date of Patent: April 2, 2013
    Assignee: Hitachi Kokusai Electric Inc.
    Inventors: Katsuhiko Tsunehara, Yunjian Jia
  • Patent number: 8315153
    Abstract: A wireless communication equipment includes receive processing and transmit processing. The receive processing includes a Fourier transform unit that transforms all received signals to frequency region signals by Fourier transform. A demodulation unit demodulates the received signals from the Fourier-transformed frequency region signals. A random access detection unit that monitors signals in frequency regions of random access signals of the Fourier-transformed frequency region signals, and detects that the random access signals are received, by a change pattern of the signals in the frequency regions of random access signals in one transmission time interval.
    Type: Grant
    Filed: August 5, 2009
    Date of Patent: November 20, 2012
    Assignee: Hitachi Kokusai Electric Inc.
    Inventors: Yunjian Jia, Katsuhiko Tsunehara
  • Publication number: 20120140658
    Abstract: Provided is a wireless communication system which includes a wireless communication unit using plural frequency bands and plural antennas. The system changes the transmission power of each antenna, based on the interference of each of the frequency bands from the neighbor base station along the antenna direction. The system estimates the number of antennas necessary for transmission in response to a user requirement, and determines a necessary antenna in accordance with the antenna direction in which the terminal is located, and further changes the transmission power of each antenna.
    Type: Application
    Filed: December 1, 2011
    Publication date: June 7, 2012
    Inventors: Hajime KANZAKI, Kenzaburo Fujishima, Mikio Kuwahara, Katsuhiko Tsunehara
  • Publication number: 20120120876
    Abstract: In a cellular radio communication system, a base station or a mobile station has a TA (Time Alignment)-range-out detection function, so that when a TA-range-out state that is unable to compensate with a guard interval is detected, the transmission condition of an uplink signal at the mobile station is changed by the mobile station autonomously or by the base station and the mobile station cooperatively.
    Type: Application
    Filed: January 24, 2012
    Publication date: May 17, 2012
    Inventors: Tomonori YAMAMOTO, Katsuhiko TSUNEHARA, Satoshi TAMAKI, May TAKADA, Mikio KUWAHARA
  • Patent number: 8165620
    Abstract: Disclosed is the hardware construction of a radio communication apparatus that can meet advanced radio communications. A control bus for transferring control signals between a main processor and components is separated from a data bus for transferring transmission/receive signals between processor units including sub-processors and an external interface. The sub-processors constitute the processor units, and a software defined radio of the present invention may include plural processor units. The processor units are connected by a dedicated interunit interface. The processor units may include multiple sub-processors, which are connected serially through an interprocessor interface.
    Type: Grant
    Filed: August 24, 2005
    Date of Patent: April 24, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Katsuhiko Tsunehara, Hirotake Ishii
  • Patent number: 8111683
    Abstract: In a cellular radio communication system, a base station or a mobile station has a TA (Time Alignment)-range-out detection function, so that when a TA-range-out state that is unable to compensate with a guard interval is detected, the transmission condition of an uplink signal at the mobile station is changed by the mobile station autonomously or by the base station and the mobile station cooperatively.
    Type: Grant
    Filed: February 24, 2009
    Date of Patent: February 7, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Tomonori Yamamoto, Katsuhiko Tsunehara, Satoshi Tamaki, May Takada, Mikio Kuwahara
  • Patent number: 7969347
    Abstract: By using the delay profile created by delay profile creating section 102 and the first threshold value 330 received from the first threshold value calculation 105, the first threshold value timing detection section 103 selects only the earliest receive timing exceeding the first threshold value, from all the timing that the correlation value in the delay profile becomes a maximum. By using the receive timing and the second threshold value 331 received from the second threshold value calculation section 107, reference timing calculation section 106 selects the reference timing required for calculating the receive timing for the incoming wave of the minimum propagation delay time. The timing delayed by previously set timing behind said reference timing is sent from receive timing calculation section 108 as the receive timing 113 of the incoming wave of the minimum propagation delay time.
    Type: Grant
    Filed: January 4, 2010
    Date of Patent: June 28, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Katsuhiko Tsunehara, Nobukazu Doi, Mikio Kuwahara, Tomoaki Ishifuji
  • Publication number: 20110038249
    Abstract: A discontinuous change in a transmission timing in a time domain, which is caused by a transmission timing adjustment processing of an OFDMA uplink or the like, brings about a discontinuous rotation of a signal phase in a frequency domain, resulting in reduced communication quality. A wireless communication system of the present invention allows the signal phase of the frequency domain in a receiving station to be continuous before and after the timing adjustment processings by controlling a signal sequence in a transmission signal after conversion in the time domain in synchronization with the timing adjustment processing.
    Type: Application
    Filed: February 16, 2009
    Publication date: February 17, 2011
    Inventors: Satoshi Tamaki, Mikio Kuwahara, Kenzaburo Fujishima, Pinai Linwong, Katsuhiko Tsunehara
  • Publication number: 20100234035
    Abstract: A radio communications system includes at least one terminal communication unit having one antenna that conducts a radio communication with a plurality of terminals; and at least one baseband modem that generates and decrypts a data signal, a cell being configured by at least one of the antenna, wherein the baseband modem divides a radio frequency band used for the radio communication into two or more subbands, generates and decrypts the data signal specific to each of the divided subbands, and allocates the data signal specific to the subband to the terminal communication unit, and wherein the terminal communication unit receives the data signal specific to the subband generated by the baseband modem, and forms the cell of each the subband by the data signal specific to the received subband.
    Type: Application
    Filed: February 23, 2010
    Publication date: September 16, 2010
    Applicant: HITACHI, LTD.
    Inventors: Kenzaburo Fujishima, May Takada, Katsuhiko Tsunehara, Satoshi Tamaki, Shinya Sasaki, Go Ono, Koki Uwano
  • Patent number: 7756489
    Abstract: A radio communication apparatus having a radio modem for processing a signal in a radio frequency band, a signal processor for processing a base band of a transmission or reception signal, and a CPU for processing a protocol. The signal processor includes signal processing blocks implemented by programmable software. Each of the signal processing blocks processes a signal of reception signal data input from the radio modem or from a preceding stage of one of the signal processing blocks or a signal of transmission signal data input from the CPU or from the preceding stage of signal processing block on the basis of a control signal input together with the transmission signal data or the reception signal data. The control signal can include information required by all the signal processing blocks in a common format.
    Type: Grant
    Filed: February 8, 2006
    Date of Patent: July 13, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Takashi Ishikawa, Manabu Kawabe, Katsuhiko Tsunehara, Hirotake Ishii
  • Publication number: 20100157898
    Abstract: To control the communication quality on the terminal basis without making the base station more complicated, it is provided a communication system, comprising at least one computer and a gateway that is connected to the at least one computer through a first network. The gateway is connected to at least one terminal through a second network. The at least one terminal performs communications with the at least one computer via the gateway. The gateway estimates quality of the communications between the gateway and the at least one computer in the first network; and determines a priority for the communications between the gateway and the at least one terminal in the second network according to the estimated quality of the communications in the first network.
    Type: Application
    Filed: December 8, 2009
    Publication date: June 24, 2010
    Applicant: HITACHI, LTD.
    Inventors: Katsuhiko TSUNEHARA, Daisuke MATSUBARA, Seishi HANAOKA, Masashi YANO
  • Publication number: 20100103047
    Abstract: By using the delay profile created by delay profile creating section 102 and the first threshold value 330 received from the first threshold value calculation 105, the first threshold value timing detection section 103 selects only the earliest receive timing exceeding the first threshold value, from all the timing that the correlation value in the delay profile becomes a maximum. By using the receive timing and the second threshold value 331 received from the second threshold value calculation section 107, reference timing calculation section 106 selects the reference timing required for calculating the receive timing for the incoming wave of the minimum propagation delay time. The timing delayed by previously set timing behind said reference timing is sent from receive timing calculation section 108 as the receive timing 113 of the incoming wave of the minimum propagation delay time.
    Type: Application
    Filed: January 4, 2010
    Publication date: April 29, 2010
    Applicant: HITACHI, LTD.
    Inventors: Katsuhiko Tsunehara, Nobukazu Doi, Mikio Kuwahara, Tomoaki Ishifuji
  • Patent number: 7663532
    Abstract: By using the delay profile created by delay profile creating section 102 and the first threshold value 330 received from the first threshold value calculation 105, the first threshold value timing detection section 103 selects only the earliest receive timing exceeding the first threshold value, from all the timing that the correlation value in the delay profile becomes a maximum. By using the receive timing and the second threshold value 331 received from the second threshold value calculation section 107, reference timing calculation section 106 selects the reference timing required for calculating the receive timing for the incoming wave of the minimum propagation delay time. The timing delayed by previously set timing behind said reference timing is sent from receive timing calculation section 108 as the receive timing 113 of the incoming wave of the minimum propagation delay time.
    Type: Grant
    Filed: October 30, 2007
    Date of Patent: February 16, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Katsuhiko Tsunehara, Nobukazu Doi, Mikio Kuwahara, Tomoaki Ishifuji
  • Publication number: 20100034078
    Abstract: In a method by which a base station detects a random access signal transmitted by a user equipment to send a transmission request to the base station in uplinks, the base station omits a MF used only to detect the random access signal, or Fourier transform and inverse Fourier transform meeting the random access signal, and uses a Fourier transform unit for data reception to detect the random access signal. Using output of the Fourier transform unit for data reception, which transmits all received signals to frequency region signals, it is judged whether a random access signal is received by a power pattern of bands allocated to the random access signals in one transmission time interval.
    Type: Application
    Filed: August 5, 2009
    Publication date: February 11, 2010
    Applicant: HITACHI KOKUSAI ELECTRIC INC.
    Inventors: Yunjian JIA, Katsuhiko TSUNEHARA
  • Publication number: 20090307567
    Abstract: The error correction capability for wireless communication carried out involving propagation path fluctuation in time and frequency selectivity can be improved. A soft decision likelihood value inputted to an error correction decoder is multiplied by a weight determined according to the distance between the data symbol and pilot symbol corresponding to the soft decision likelihood value. Namely, the soft decision bit likelihood value corresponding to the data symbol is weighted according to the distances in time or frequency between the pilot symbol and data symbol. The weight is made smaller when the distance in time or frequency is larger.
    Type: Application
    Filed: May 28, 2009
    Publication date: December 10, 2009
    Applicant: HITACHI KOKUSAI ELECTRIC INC.
    Inventors: Katsuhiko Tsunehara, Yunjian Jia