Patents by Inventor Youichi Moritani

Youichi Moritani 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: 6930993
    Abstract: In a TDMA communication system in which a base station communicates with a plurality of subscriber stations, communication time slots used in a wireless communication are allocated/arranged while avoiding an occurrence of interference. In the case that interference (51) occurs in a communication time slot (411) of a line (71) through which the communication is made from a subscriber station (21) to a base station (1), interference information is registered into an interference time slot database (101) of the base station (1). When the communication time slots are reallocated and rearranged, a TDMA control unit of the base station (1) executes the communication time slot reallocation/rearrangement by referring to information registered in the interference time slot database (101), so that the occurrence of interference is avoided.
    Type: Grant
    Filed: September 30, 1998
    Date of Patent: August 16, 2005
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Tomokazu Hamada, Youichi Moritani, Takashi Kawabata, Shuji Ito
  • Patent number: 6873607
    Abstract: In a radio communication system in which multiple access is carried out between a base station and a plurality of subscriber stations by a TDMA communication method, occurrence of the interference in the R channels through which the subscriber stations (21 to 24) issue a call request to the base station (1) can be detected precisely, and time slot arrangement of the R channels is changed by detecting the interference to thus avoid the interference.
    Type: Grant
    Filed: September 30, 1998
    Date of Patent: March 29, 2005
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Tomokazu Hamada, Youichi Moritani, Takashi Kawabata, Shuji Ito
  • Patent number: 6424645
    Abstract: A TDMA radio communication method including the steps of: providing a latter part of each of super frames with an assignment information notification period which is preceded by an assignment processing period, and providing a remaining part of the each of the super frame with an assignment request collecting period; transmitting, from a terminal station to a base station, assignment request information using a plurality of frames included in the assignment request collecting period; transmitting, from the base station to the terminal station, frame structure information and assignment information over a plurality of frames included in the assignment information notification period; and carrying out, in the base station, channel assignment of a radio channel, changes of the frame structure and of the channel assignment in response to timings of the super frames.
    Type: Grant
    Filed: April 29, 1999
    Date of Patent: July 23, 2002
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takashi Kawabata, Youichi Moritani, Tomokazu Hamada, Tohru Sogabe
  • Patent number: 6282422
    Abstract: A radio communication apparatus capable of solving a problem involved in a conventional apparatus in that in addition to a first receiver, a second receiver must be provided for establishing synchronization with a contiguous base station, which causes an increase in a circuit scale and consumed power of a mobile station. The present radio communication apparatus switches, when carrying out handoff from the current base station to a contiguous base station, a receiving frequency of a receiver from the frequency of the current base station to that of the contiguous base station, and a counter to be corrected by a synchronization manager from a first counter to a second counter that is used to establish synchronization with the contiguous base station.
    Type: Grant
    Filed: March 2, 1999
    Date of Patent: August 28, 2001
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Hideto Aikawa, Akihiro Shibuya, Youichi Moritani