Patents by Inventor Takaki Uta

Takaki Uta 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: 7890118
    Abstract: In a position detection system utilizing a WLAN supporting multiple data transfer rates, it is possible to reduce the number of required installed base stations, so system construction costs can be lowered. In a wireless station, a transmitted signal is judged at the time of transmission, and in case it is normal user data, the signal is transmitted by setting optimal transmission parameters for which a high communication throughput with wireless communication is obtained, and in case it is a position detection signal, the aforementioned signal is transmitted by setting transmission parameters for which the service range is increased. As a transmission parameter for which the service range is increased, a low data transfer rate or a long preamble length is used.
    Type: Grant
    Filed: November 8, 2005
    Date of Patent: February 15, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Takaki Uta, Atsushi Ogino, Ryota Yamasaki, Kumiko Takikawa
  • Patent number: 7848766
    Abstract: In any indoor location, whenever operating a wireless terminal position detecting system comprising a transferable wireless terminal, a plurality of base stations individually allowing a connection from said wireless terminal, and a plurality of wireless receiving stations individually receiving wireless signal from said terminal and base stations, there is a problem in terms of the provision of a method for minimizing positional detection error on the part of said wireless terminal and a method for practically realizing said method.
    Type: Grant
    Filed: July 10, 2006
    Date of Patent: December 7, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Atsushi Ogino, Ryota Yamasaki, Takaki Uta
  • Patent number: 7509139
    Abstract: When one base station to which a terminal is to connect is determined from a plurality of base stations in a wireless communication system, the best base station is selected according to the communication quality or the content of communication services. In the wireless communication system, the plurality of base stations are classified into a plurality of groups. Indexes of communication quality between the base stations and the terminal are obtained and, for each group, the characterizing quantities of the indexes of communication quality are calculated. The base station group with which the terminal is to communicate is specified based on the characterizing quantities. One of the base stations in the specified group is determined as a communication destination base station.
    Type: Grant
    Filed: January 11, 2006
    Date of Patent: March 24, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Ryota Yamasaki, Kumiko Takikawa, Atsushi Ogino, Takaki Uta
  • Publication number: 20080170555
    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: March 14, 2008
    Publication date: July 17, 2008
    Inventors: Katsuhiko Tsunehara, Takashi Yano, Nobukazu Doi, Takaki Uta, Keiji Hasegawa
  • Patent number: 7345630
    Abstract: In a position detection system for detecting a position of a terminal apparatus of a radio communications system, a position detection time is shortened using a position detection method for determining signal times-of-arrival between the terminal apparatus and base stations neighboring the terminal apparatus. According to the present invention, means for generating a database in which received power information about signals transferred between the terminal apparatus and the base stations neighboring the terminal apparatus corresponds to position information about the terminal apparatus, and for determining the position information by searching received power information obtained in the position detection from the database, and means for determining the position by use of signal times-of-arrival are executed in parallel. Then, the use of a result of the means which has detected the position earlier than another means shortens the position detection time.
    Type: Grant
    Filed: October 12, 2006
    Date of Patent: March 18, 2008
    Assignee: Hitachi, Ltd.
    Inventors: Tsuyoshi Tamaki, Atsushi Ogino, Takaki Uta, Ryota Yamasaki
  • Publication number: 20080045261
    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: October 15, 2007
    Publication date: February 21, 2008
    Inventors: Katsuhiko Tsunehara, Takashi Yano, Nobukazu Doi, Takaki Uta, Keiji Hasegawa
  • Patent number: 7319684
    Abstract: A system and method are provided for wireless communication. In one example, a wireless communication system that enhances total system throughput is provided. The system performs parallel data transmission from a plurality of access points to a plurality of user terminals. On terminals with power control function, their transmit power can be set to minimize interference. The wireless communication system comprises a management server which performs centralized management of time of access-point-to-terminal packet transmission, access points, and user terminals that perform data transmission, according to transmission time control information from the management server. Transmit queues for measuring downlink traffic and receive queues for measuring uplink traffic are provided on the access points or the management server. The system determines uplink and downlink periods from the transmit and receive queue lengths.
    Type: Grant
    Filed: June 2, 2003
    Date of Patent: January 15, 2008
    Assignee: Hitachi, Ltd.
    Inventors: Tsuyoshi Tamaki, Takashi Yano, Takaki Uta, Tomoaki Ishifuji
  • Publication number: 20070090995
    Abstract: In a position detection system for detecting a position of a terminal apparatus of a radio communications system, a position detection time is shortened using a position detection method for determining signal times-of-arrival between the terminal apparatus and base stations neighboring the terminal apparatus. According to the present invention, means for generating a database in which received power information about signals transferred between the terminal apparatus and the base stations neighboring the terminal apparatus corresponds to position information about the terminal apparatus, and for determining the position information by searching received power information obtained in the position detection from the database, and means for determining the position by use of signal times-of-arrival are executed in parallel. Then, the use of a result of the means which has detected the position earlier than another means shortens the position detection time.
    Type: Application
    Filed: October 12, 2006
    Publication date: April 26, 2007
    Inventors: Tsuyoshi Tamaki, Atsushi Ogino, Takaki Uta, Ryota Yamasaki
  • Publication number: 20070032248
    Abstract: In any indoor location, whenever operating a wireless terminal position detecting system comprising a transferable wireless terminal, a plurality of base stations individually allowing a connection from said wireless terminal, and a plurality of wireless receiving stations individually receiving wireless signal from said terminal and base stations, there is a problem in terms of the provision of a method for minimizing positional detection error on the part of said wireless terminal and a method for practically realizing said method.
    Type: Application
    Filed: July 10, 2006
    Publication date: February 8, 2007
    Inventors: Atsushi Ogino, Ryota Yamasaki, Takaki Uta
  • Patent number: 7138946
    Abstract: In a position detection system for detecting a position of a terminal apparatus of a radio communications system, a position detection time is shortened using a position detection method for determining signal times-of-arrival between the terminal apparatus and base stations neighboring the terminal apparatus. According to the present invention, means for generating a database in which received power information about signals transferred between the terminal apparatus and the base stations neighboring the terminal apparatus corresponds to position information about the terminal apparatus, and for determining the position information by searching received power information obtained in the position detection from the database, and means for determining the position by use of signal times-of-arrival are executed in parallel. Then, the use of a result of the means which has detected the position earlier than another means shortens the position detection time.
    Type: Grant
    Filed: June 15, 2004
    Date of Patent: November 21, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Tsuyoshi Tamaki, Atsushi Ogino, Takaki Uta, Ryota Yamasaki
  • Publication number: 20060234756
    Abstract: When one base station to which a terminal is to connect is determined from a plurality of base stations in a wireless communication system, the best base station is selected according to the communication quality or the content of communication services. In the wireless communication system, the plurality of base stations are classified into a plurality of groups. Indexes of communication quality between the base stations and the terminal are obtained and, for each group, the characterizing quantities of the indexes of communication quality are calculated. The base station group with which the terminal is to communicate is specified based on the characterizing quantities. One of the base stations in the specified group is determined as a communication destination base station.
    Type: Application
    Filed: January 11, 2006
    Publication date: October 19, 2006
    Inventors: Ryota Yamasaki, Kumiko Takikawa, Atsushi Ogino, Takaki Uta
  • Patent number: 7061968
    Abstract: In a mobile communication system, the tracking of synchronization is conducted in a stable state even in a multipath environment. A delay profile detector calculates a delay profile a(n) using a despread signal for each processing unit n. A delay profile averaging unit averages a(n) to produce Ave(|a(n)|2). A data symbol detector conducts rake combining of the despread signal using a(n) and Ave(|a(n)|2). According to a(n) and Ave(|a(n)|2, a weighting function unit calculates a representative value representing delay waves. A loop filter generates a control signal in response to the representative value. A clock controller controls a spread code generator according to the control signal.
    Type: Grant
    Filed: May 18, 2004
    Date of Patent: June 13, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Takashi Yano, Takaki Uta, Nobukazu Doi, Toshiro Suzuki
  • Publication number: 20060105779
    Abstract: In a position detection system utilizing a WLAN supporting multiple data transfer rates, it is possible to reduce the number of required installed base stations, so system construction costs can be lowered. In a wireless station, a transmitted signal is judged at the time of transmission, and in case it is normal user data, the signal is transmitted by setting optimal transmission parameters for which a high communication throughput with wireless communication is obtained, and in case it is a position detection signal, the aforementioned signal is transmitted by setting transmission parameters for which the service range is increased. As a transmission parameter for which the service range is increased, a low data transfer rate or a long preamble length is used.
    Type: Application
    Filed: November 8, 2005
    Publication date: May 18, 2006
    Inventors: Takaki Uta, Atsushi Ogino, Ryota Yamasaki, Kumiko Takikawa
  • 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: 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: 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: 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
  • Publication number: 20050101331
    Abstract: A method and system are provided for controlling position detection of a terminal in a network. In one example, a wireless communications system operates as a position determination system to determine the position of a terminal, based on the measurements of time difference of arrival (TDOA) of radio signals sent from the terminal and received at a plurality of base stations in the vicinity of the terminal, while preventing the loss of packets sent from terminals to the base stations.
    Type: Application
    Filed: June 16, 2004
    Publication date: May 12, 2005
    Inventors: Tsuyoshi Tamaki, Atsushi Ogino, Takaki Uta, Ryota Yamasaki
  • Publication number: 20050078033
    Abstract: In a position detection system for detecting a position of a terminal apparatus of a radio communications system, a position detection time is shortened using a position detection method for determining signal times-of-arrival between the terminal apparatus and base stations neighboring the terminal apparatus. According to the present invention, means for generating a database in which received power information about signals transferred between the terminal apparatus and the base stations neighboring the terminal apparatus corresponds to position information about the terminal apparatus, and for determining the position information by searching received power information obtained in the position detection from the database, and means for determining the position by use of signal times-of-arrival are executed in parallel. Then, the use of a result of the means which has detected the position earlier than another means shortens the position detection time.
    Type: Application
    Filed: June 15, 2004
    Publication date: April 14, 2005
    Inventors: Tsuyoshi Tamaki, Atsushi Ogino, Takaki Uta, Ryota Yamasaki
  • 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