Patents by Inventor Rintaro Katayama

Rintaro Katayama 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: 20100238876
    Abstract: A method for radio resource control is carried out in a radio communications system including multiple base stations. In this method, a radio resource that can be used by the base stations is divided into multiple first radio resources on the frequency axis. Then one or more of the first radio resources are allocated to a second radio resource for initially transmitting a packet and the other first radio resources are allocated to a third radio resource for retransmitting the packet.
    Type: Application
    Filed: February 18, 2010
    Publication date: September 23, 2010
    Applicant: HITACHI, LTD.
    Inventors: Tomonori YAMAMOTO, Rintaro KATAYAMA, Keisuke TAKEUCHI, Koki UWANO
  • Publication number: 20100182972
    Abstract: In a conventional OFDMA/SCFDMA communication scheme, frequency resource assignment information is exchanged between BSs via a wired interface and used for control of inter-cell interference or the like. When a BS performs assignments of frequency resources, taking the status of a neighbor BS signaled via the wired interface into account, it might be impossible to follow a change in the status of the assignments of frequency resources at the neighbor BS due to a delay occurring in the wired interface. BS selects and assigns distributed frequency resources or continuous frequency resources, depending on the position of an MS in the cell and the transmit power of the BS.
    Type: Application
    Filed: January 19, 2010
    Publication date: July 22, 2010
    Applicant: HITACHI, LTD.
    Inventors: Rintaro KATAYAMA, Keisuke TAKEUCHI, Tomonori YAMAMOTO, Koki UWANO
  • Publication number: 20100157831
    Abstract: A base station is connected to wired and wireless networks to send a call that is received from the wired network to the wireless network at a predetermined quality of service (QoS), select one or more combinations of a set of modulation and coding scheme, and a radio resource amount that are associated with a QoS set in a newly incoming call, determine the radio resource amount that is equal to or less than a amount of the unassigned radio resources, assign, to the newly incoming call, the combination that is associated with the determined radio resource amount and the QoS set in the newly incoming call, reduce the radio resources assigned to the ongoing call without changing the QoS, and assign, to the newly incoming call, an amount of radio resources released from the ongoing call and modulation and coding scheme associated with this released radio resource amount.
    Type: Application
    Filed: December 18, 2009
    Publication date: June 24, 2010
    Applicant: HITACHI, LTD.
    Inventors: Keisuke Takeuchi, Rintaro Katayama, Tomonori Yamamoto, Koki Uwano
  • Publication number: 20090305741
    Abstract: Provided is a wireless base station comprising: a power control unit, a reference information acquisition unit and a reference information storing unit, wherein the wireless base station comprises a first control signal receiving unit for receiving a first uplink control signal used by a mobile station connected to the wireless base station and for requesting the power control unit to control the transmission, and a second control signal receiving unit for receiving a second uplink control signal used by a mobile station connected to the neighbor base station and for requesting the power control unit to control the transmission power, and wherein the power control unit controls the transmission power of the downlink signal based on the request to control the transmission power from the first control signal receiving unit and the request to control the transmission power from the second control signal receiving unit.
    Type: Application
    Filed: June 9, 2009
    Publication date: December 10, 2009
    Inventors: Keisuke TAKEUCHI, Kenzaburo FUJISHIMA, Rintaro KATAYAMA, Koki UWANO
  • Publication number: 20090245088
    Abstract: When a receiving apparatus which employs a OFDM-based cellular wireless communication scheme detects as an excessive signal for each frame, the signal having signal intensity exceeding a reference value after a Fourier transform, a gain variable according to an excessive quantity relative to the reference value is used for each frame to control signal intensity such that the amplitude thereof is at most the reference value.
    Type: Application
    Filed: February 10, 2009
    Publication date: October 1, 2009
    Inventors: Keisuke TAKEUCHI, Kenzaburo FUJISHIMA, Rintaro KATAYAMA, Koki UWANO
  • Publication number: 20090210766
    Abstract: A non-terminated packet is transmitted, by utilizing a spatial layer responded with an ACK, which is assumed as a released layer. Alternatively, a non-terminated packet is transmitted by using a released layer and an original spatial layer in combination. Alternatively, a new packet is transmitted in a released layer by utilizating time till termination of transmission of a non-terminated packet. A wireless communication system effectively utilizing a released layer, a terminal and a base station.
    Type: Application
    Filed: February 18, 2009
    Publication date: August 20, 2009
    Inventors: Rintaro Katayama, Toshiyuki Saito, Mikio Kuwahara, Koki Uwano
  • Publication number: 20090016265
    Abstract: A radio communication system of an HARQ method that makes an HARQ transmission interval of subpackets appropriate and reduces data transmission delay resulting from subpacket retransmission. In the radio communication system in which a packet is transmitted and receives with the HARQ method between a base station and multiple radio mobile stations, each of the base station and the multiple radio mobile stations has: a packet transmission circuit for transmitting subpackets in predetermined intervals; a packet reception circuit for repeating decoding processing by combining a newly received subpacket and a previously received former subpacket until an original packet is successfully decoded; and a HARQ control equipped with a function of, for packet communication whose data length is short, transmitting a subpacket or response from the packet transmission circuit in an HARQ transmission interval that is shortened from the HARQ transmission interval of the normal mode.
    Type: Application
    Filed: March 19, 2008
    Publication date: January 15, 2009
    Inventors: Rintaro KATAYAMA, Toshiyuki Saito, Shiro Mazawa, Daigo Takayanagi
  • Publication number: 20090005060
    Abstract: A wireless access terminal, after handoff, adds channel quality information calculated in the wireless access terminal to a header of transmit data and transmits this data until a wireless base station succeeds in receiving at least one or more packets. The wireless base station, when having succeeded in receiving a packet for the first time after the handoff, extracts the channel quality information from a received header to initialize channel quality information inside the wireless base station. Subsequently, the wireless base station autonomously updates the channel quality information in response to success or failure of packet reception and controls the transmission rate.
    Type: Application
    Filed: April 25, 2008
    Publication date: January 1, 2009
    Inventors: Shiro Mazawa, Toshiyuki Saito, Keisuke Takeuchi, Rintaro Katayama
  • Publication number: 20080205361
    Abstract: The present invention provides a wireless communication system and a terminal. A base station includes means that notifies terminals of an intensity of a received interference power. The terminal includes means that controls a transmission power for transmitting data to the base station, which is one of base stations and to which data is to be transmitted, by referencing an intensity of interference power (OSI) notified from base stations to which data is not to be transmitted. The means that controls a transmission power calculates a decision value for increasing/decreasing the transmission power, wherein the decision value is variable according to the current transmission power of the terminal and propagation attenuations between the terminal and the base stations to which data is not to be transmitted, and variably controls the amount of transmission power increase/decrease according to the decision value for increasing/decreasing a transmission power.
    Type: Application
    Filed: August 23, 2007
    Publication date: August 28, 2008
    Inventors: Keisuke Takeuchi, Toshiyuki Saito, Rintaro Katayama, Shiro Mazawa, Akihiko Yoshida
  • Publication number: 20080146238
    Abstract: Since the OFDM communication method does not select whether plural sectors use a same terminal as a transmission destination, or always use it as a transmission destination, giving a preference to system throughput deteriorates channel quality of a terminal in a sector boundary, while increasing channel quality in sector boundaries greatly deteriorates system throughput. In a base station, when a sector transmits to a terminal in the front of a beam, only the sector performs the transmission, and when transmission is made to a terminal in a sector boundary off the direction of the beam, a different sector transmits to the same terminal using a same hopping pattern. Thereby, tradeoff between the channel quality of the terminal in a sector boundary and deterioration in system throughput can be minimized.
    Type: Application
    Filed: August 23, 2007
    Publication date: June 19, 2008
    Inventors: Toshiyuki Saito, Rintaro Katayama, Akihiko Yoshida, Shiro Mazawa
  • Publication number: 20080076408
    Abstract: A wireless communications system, a terminal, and a base station that, when a terminal has not transmitted data for a predetermined period of time, suppress the transmission power, used when the terminal starts data transmission, by performing transmission power control that makes it easy for the terminal to decrease, or difficult for the terminal to increase, the transmission T2P or that, when a terminal that has not transmitted data for a predetermined period of time requests a sector to assign resources for data transmission, suppress the transmission power, used when the terminal starts data transmission, by transmitting a resource assignment message from the sector to the terminal to instruct the terminal to decrease the transmission power when the terminal starts data transmission.
    Type: Application
    Filed: September 7, 2007
    Publication date: March 27, 2008
    Inventors: Rintaro Katayama, Toshiyuki Saito, Shiro Mazawa, Daigo Takayanagi
  • Publication number: 20080057970
    Abstract: In a wireless communications system operating according to CDMA or the like, when one terminal simultaneously performs communication using multiple wireless resources (e.g., multiple carriers), there was a problem that when it was attempted to guarantee network mobility by the same soft handoff system as in the case where communication was performed using only one wireless resource, efficiency suffered from the viewpoint of network forwarding load, processing load and wireless resource occupancy time. Soft handoff termination is judged and soft handoff is forcibly terminated according to whether or not the data rate obtained for all resources on the network side satisfies a requested rate, based on a reception state notification from a terminal concerning wireless resources.
    Type: Application
    Filed: July 3, 2007
    Publication date: March 6, 2008
    Inventors: May Takada, Yosuke Takahashi, Shiro Mazawa, Rintaro Katayama