Patents by Inventor Hiroto ADACHI

Hiroto ADACHI 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: 8934938
    Abstract: In a cellular wireless communication system with plural antenna base stations, signals have been basically transmitted using two antennas among plural antennas, and thus power has been concentrated in specific antennas. The present invention controls the transmission power of each antenna so as not to increase the transmission power of specific antennas by effectively using plural antennas and frequency bands. A frequency band is divided into plural sub-bands, and antennas used for transmission are spread to the sub-bands. In each sub-band, power is not allocated to an antenna that is not used for transmission. As a result, the transmission power of each antenna can be balanced, and power can be prevented from being concentrated in specific antennas.
    Type: Grant
    Filed: April 13, 2012
    Date of Patent: January 13, 2015
    Assignee: Hitachi, Ltd.
    Inventor: Hiroto Adachi
  • Publication number: 20140256331
    Abstract: Information is exchanged among multiple base stations by adaptively changing an allocation of radio resource of each base station, and reducing deterioration in a signal quality that is caused by interference of signals transmitted from multiple base stations. Communication with a terminal located in a cell center and communication with a terminal located in a cell edge are performed in different time zones. In addition, communication is performed such that time zones do not overlap in the cell edge between multiple neighbor base station devices. In addition, efficiency that is an index representing the number of bits transmittable per resource element is calculated using a scanning result of a terminal, and one base station that decides a radio resource allocation between cells decides radio resources to be allocated to a terminal located in a cell center and radio resources to be allocated to the cell edge using the efficiency information.
    Type: Application
    Filed: August 16, 2012
    Publication date: September 11, 2014
    Applicant: HITACHI, LTD.
    Inventors: Hiroto Adachi, Mikio Kuwahara, Hajime Kanzaki
  • Publication number: 20120276943
    Abstract: In a cellular wireless communication system with plural antenna base stations, signals have been basically transmitted using two antennas among plural antennas, and thus power has been concentrated in specific antennas. The present invention controls the transmission power of each antenna so as not to increase the transmission power of specific antennas by effectively using plural antennas and frequency bands. A frequency band is divided into plural sub-bands, and antennas used for transmission are spread to the sub-bands. In each sub-band, power is not allocated to an antenna that is not used for transmission. As a result, the transmission power of each antenna can be balanced, and power can be prevented from being concentrated in specific antennas.
    Type: Application
    Filed: April 13, 2012
    Publication date: November 1, 2012
    Inventor: Hiroto ADACHI