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: 20060092886
    Abstract: An uplink channel transmission power control method is provided for a CDMA mobile communication system performing one way communication. A base station measures the received level of data transmitted from each mobile terminal at each channel, and generates a transmission power control signal of each uplink traffic channel. The generated transmission power control signals are multiplexed, and the multiplexed common transmission power control signal is transmitted to all mobile terminals by using the common channel shared by the mobile terminals. Each mobile terminal derives the transmission power control signal of the uplink traffic channel used by the terminal, from the received common transmission power control signal, and controls the transmission power of a data packet.
    Type: Application
    Filed: December 15, 2005
    Publication date: May 4, 2006
    Inventors: Katsuhiko Tsunehara, Takashi Yano, Nobukazu Doi, Takaki Uta, Keiji Hasegawa
  • Patent number: 7016653
    Abstract: A radio terminal that receives signals from a plurality of radio stations to calculate its current position has: interference canceling means for canceling each interference signal from the plurality of received signals; a plurality of delay profile generating means for generating delay profiles of the plurality of interference-canceled received signals with use of respective corresponding codes; and position calculating means for calculating its current position, which is a signal receiving point, with use of the plurality of delay profiles, whereby advantageously reducing the capacity of a memory mounted in the mobile terminal while the position calculation is speeded up
    Type: Grant
    Filed: June 27, 2002
    Date of Patent: March 21, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Katsuhiko Tsunehara, Mikio Kuwahara
  • Publication number: 20060052094
    Abstract: To simplify the configuration of functional modules in a software-defined radio apparatus, and facilitate the development of software. The functional modules have input and output terminals of a common configuration. Distributed timing control is performed so that the functional modules operate in their respective timings, and the functional modules have common input/output signals.
    Type: Application
    Filed: September 6, 2005
    Publication date: March 9, 2006
    Inventors: Manabu Kawabe, Katsuhiko Tsunehara, Hirotake Ishii, Takashi Ishikawa
  • Publication number: 20060046771
    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: Application
    Filed: August 24, 2005
    Publication date: March 2, 2006
    Inventors: Katsuhiko Tsunehara, Hirotake Ishii, Manabu Kawabe, Takashi Ishikawa
  • Publication number: 20060045212
    Abstract: The invention provides a technique that saves rate conversion accompanying complicated calculations and shares an analog filter for anti-aliasing in a sampling device. The sampling device employs an anti-alias filter having a fixed cutoff frequency, an A/D converter and a D/A converter each having a clock signal input, which are capable of varying a sampling frequency, and a PLL circuit capable of varying the frequency of a clock signal; and it sets the sampling frequency not lower than an integral multiple of a signal bandwidth and double the cutoff frequency for sampling.
    Type: Application
    Filed: January 3, 2005
    Publication date: March 2, 2006
    Inventors: Hirotake Ishii, Katsuhiko Tsunehara, Takashi Yano
  • Patent number: 7006475
    Abstract: On the side of a mobile station, interference of a perch channel with call control information or a traffic channel is reduced, realizing stable communication. In a method of CDMA communication in which communication is made through the traffic channel for transmitting user data and the perch channel for transmitting a spreading code used for demodulation of the user data, the traffic channel has a call control channel subjected to the time division multiplex, and that call control channel and a part of the perch channel, which is non-orthogonal to the call control channel, are arranged not to overlap with each other in a time base.
    Type: Grant
    Filed: December 21, 1999
    Date of Patent: February 28, 2006
    Assignees: Hitachi, Ltd., KDDI Corporation
    Inventors: Toshiro Suzuki, Takashi Yano, Takaki Uta, Katsuhiko Tsunehara, Hisato Iwai
  • Patent number: 7006463
    Abstract: An uplink channel transmission power control method is provided for a CDMA mobile communication system performing one way communication. A base station measures the received level of data transmitted from each mobile terminal at each channel, and generates a transmission power control signal of each uplink traffic channel. The generated transmission power control signals are multiplexed, and the multiplexed common transmission power control signal is transmitted to all mobile terminals by using the common channel shared by the mobile terminals. Each mobile terminal derives the transmission power control signal of the uplink traffic channel used by the terminal, from the received common transmission power control signal, and controls the transmission power of a data packet.
    Type: Grant
    Filed: October 3, 2002
    Date of Patent: February 28, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Katsuhiko Tsunehara, Takashi Yano, Nobukazu Doi, Takaki Uta, Keiji Hasegawa
  • Patent number: 6990351
    Abstract: Even in areas where signals from only two or less base stations are available for position calculation, the mobile handset position can be calculated, expanding the position information service area and improving the usefulness. When the number of base stations available for position calculation is three or more, the position calculation is performed based on trilateration. When the number of available base stations is two or one, the position calculation is performed by using a two-station-based position calculation method or a one-station-based position calculation method according to the number of available base stations.
    Type: Grant
    Filed: February 19, 2002
    Date of Patent: January 24, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Katsuhiko Tsunehara, Mikio Kuwahara
  • Publication number: 20050272464
    Abstract: An AD/DA converter is equipped to the wireless communication device main unit side, and a transmission and reception base band filter is equipped to the wireless module side. Due to this arrangement, miniaturization and setting of the cost at a low level of the wireless module replaced for every communication system and the wireless communication device as a total become possible.
    Type: Application
    Filed: April 4, 2005
    Publication date: December 8, 2005
    Inventors: Takashi Ishikawa, Katsuhiko Tsunehara, Hirotake Ishii
  • Patent number: 6950661
    Abstract: A location calculation method for calculating, by using propagation delay time of signals received from wireless transmitters, a location of a reception point of the signals to thereby reduce errors in the distance measurement due to an erroneous detection of a path of a received signal includes first step of measuring reception timing of signals received from the wireless transmitters, second step of estimating, according to results of measurement of the reception timing obtained by the first step, an erroneous result of measurement, and third step of removing the results of measurement estimated as the erroneous results by the second step from the results of measurement of the reception timing obtained by the first step, and thereby calculating the location of the reception point.
    Type: Grant
    Filed: January 8, 2002
    Date of Patent: September 27, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Koji Watanabe, Mikio Kuwahara, Katsuhiko Tsunehara, Kenzaburo Fujishima
  • Patent number: 6928292
    Abstract: To extend the areas where a mobile handset can determine its position using radio waves, the present invention provides a mobile handset that is equipped with both position calculation means using radio waves from GPS satellites and position calculation means using RF carriers from cellular base stations. Positioning results obtained from both of these position calculation means are combined and weighted with GPS positioning reliability and cellular positioning reliability, respectively. A weighted mean of these results is then output as a final position calculation result.
    Type: Grant
    Filed: March 12, 2002
    Date of Patent: August 9, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Katsuhiko Tsunehara, Mikio Kuwahara
  • Publication number: 20050140543
    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: February 17, 2005
    Publication date: June 30, 2005
    Inventors: Katsuhiko Tsunehara, Nobukazu Doi, Mikio Kuwahara, Tomoaki Ishifuji
  • Patent number: 6907260
    Abstract: The present invention provides a transmit power controlling method for reducing an influence of incorrect control in a mobile communication system in the CDMA mode. A likelihood of transmit power controlling signal is generated on the basis of the transmit power controlling signal transmitted by a radio base station and the receiving quality, a variation amount of the transmit power is generated on the basis of the likelihood, and the transmit power of a mobile station is controlled on the basis of the variation amount.
    Type: Grant
    Filed: December 21, 1999
    Date of Patent: June 14, 2005
    Assignees: KDDI Corporation, Hitachi, Ltd.
    Inventors: Katsuhiko Tsunehara, Takashi Yano, Takaki Uta, Toshiro Suzuki, Toshinori Suzuki
  • Patent number: 6900753
    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 section 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 8, 2003
    Date of Patent: May 31, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Katsuhiko Tsunehara, Nobukazu Doi, Mikio Kuwahara, Tomoaki Ishifuji
  • Publication number: 20050078626
    Abstract: A method and system for detecting the position of a mobile unit efficiently and with high precision in a multipath environment. A wireless position detection system made up of a mobile station containing a wireless communication means to allow sending and receiving multiple to and from mutually different antenna positions and, a base station for performing wireless communication with mobile stations containing a wireless communication means and, multiple wireless receivers for receiving each of the multiple signals sent by the wireless communication means between the base stations and, a server for detecting the position of the mobile station from each wireless receiver and from the position of the base station, and the time relating to received signals measured by the multiple wireless receivers.
    Type: Application
    Filed: October 4, 2004
    Publication date: April 14, 2005
    Inventors: Atsushi Ogino, Ryota Yamasaki, Katsuhiko Tsunehara, Naoto Matsuzawa, Hideya Suzuki, Takashi Yano
  • Publication number: 20050014525
    Abstract: The present invention reduces the number of base stations required to carry out terminal position detection. A base station which serves for terminal position detection using radio signals comprises an antenna to transmit and receive a radio signal; a radio signal receiver which generates a received signal from the radio signal received; a signal processing unit which processes the received signal and generates a transmit signal; a radio signal transmitter which generates a radio signal from the transmit signal; a control unit which exerts control of the base station operation; and a signal processing unit for position detection which performs signal processing for terminal position detection. A signal receivable range with which a signal can be received by the radio signal receiver is made longer than a signal transmission range with which a signal is transmitted by the radio signal transmitter.
    Type: Application
    Filed: May 19, 2004
    Publication date: January 20, 2005
    Inventors: Katsuhiko Tsunehara, Takashi Yano
  • Publication number: 20040266473
    Abstract: The present invention provides a transmit power controlling method for reducing an influence of incorrect control in a mobile communication system in the CDMA mode. A likelihood of transmit power controlling signal is generated on the basis of the transmit power controlling signal transmitted by a radio base station and the receiving quality, a variation amount of the transmit power is generated on the basis of the likelihood, and the transmit power of a mobile station is controlled on the basis of the variation amount.
    Type: Application
    Filed: July 27, 2004
    Publication date: December 30, 2004
    Inventors: Katsuhiko Tsunehara, Takashi Yano, Takaki Uta, Toshiro Suzuki, Toshinori Suzuki
  • Publication number: 20040214521
    Abstract: In an access point apparatus for a wireless LAN system equipped with a terminal location detecting function, memory capacity required for the access point apparatus is reduced. A received signal memory control module (120) controls access such that a memory space of a received signal memory (102) can be reused by performing sequentially overwrite operation while stopping capturing of the received signal in response to a packet detection signal outputted from a packet detecting module (121).
    Type: Application
    Filed: March 2, 2004
    Publication date: October 28, 2004
    Inventors: Katsuhiko Tsunehara, Takashi Yano
  • Publication number: 20040172190
    Abstract: In the present invention, even if a mobile terminal is close to a base station, the position of the mobile terminal is measured accurately. The disclosed method for calculating the position of a mobile terminal comprises: measuring the differences between the propagation distances of the signals on the channels between a plurality of base stations and the mobile terminal; determining if the mobile terminal is close to a base station; calculating the position of the mobile terminal by a common formula if it is determined that the mobile terminal is not in close proximity to any of the base stations; calculating the position of the mobile terminal in close proximity to a base station if it is determined that the mobile terminal is in close proximity to one of the base stations; and outputting the position of the mobile terminal calculated through either of the routines for calculating the mobile terminal position.
    Type: Application
    Filed: January 14, 2004
    Publication date: September 2, 2004
    Applicant: Hitachi, Ltd.
    Inventors: Katsuhiko Tsunehara, Kenzaburo Fujishima
  • Publication number: 20040066332
    Abstract: Under a multi-path environment, receive timing for the incoming wave of the minimum propagation delay time cannot be accurately measured using the prior art.
    Type: Application
    Filed: October 8, 2003
    Publication date: April 8, 2004
    Applicant: Hitachi, Ltd.
    Inventors: Katsuhiko Tsunehara, Nobukazu Doi, Mikio Kuwahara, Tomoaki Ishifuji