Patents by Inventor Yoshiaki Ofuji

Yoshiaki Ofuji 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: 20090147748
    Abstract: A disclosed transmission apparatus comprises a switching portion that switches radio access methods; a frequency domain signal generation portion that allocates a radio resource to a spread chip sequence on which one of a fast Fourier transformation and a series/parallel conversion is performed in accordance with the switched radio accessed method, so as to generate a signal in a frequency domain; and a transmission signal generation portion that performs a fast inverse Fourier transformation on the signal in the frequency domain so as to generate a transmission signal.
    Type: Application
    Filed: March 23, 2006
    Publication date: June 11, 2009
    Applicant: NTT DOCOMO, INC.
    Inventors: Yoshiaki Ofuji, Hiroyuki Atarashi, Kenichi Higuchi, Mamoru Sawahashi
  • Publication number: 20090129362
    Abstract: A disclosed transmission device includes a frequency scheduling unit configured to allocate, to each user, either frequency blocks that are consecutive frequency subcarrier blocks obtained by dividing a system bandwidth or distributed frequency blocks that are frequency subcarrier blocks discretely distributed in the system bandwidth; and a mapping unit configured to assign transmission data to the frequency blocks or the distributed frequency blocks according to the allocation result. The frequency scheduling unit is configured to allocate the distributed frequency blocks using the frequency blocks as units and to allocate sub-blocks obtained by dividing the respective distributed frequency blocks.
    Type: Application
    Filed: February 5, 2007
    Publication date: May 21, 2009
    Applicant: NTT DOCOMO, INC.
    Inventors: Kenichi Higuchi, Yoshihisa Kishiyama, Yoshiaki Ofuji, Satoshi Nagata, Mamoru Sawahashi
  • Publication number: 20090034638
    Abstract: An apparatus for generating sets of radio parameters includes a first deriving unit deriving a set of radio parameters for specifying a symbol including an effective symbol part with the same period as the effective symbol part specified by another set of radio parameters and a guard interval part with a different period from the guard interval part specified by the other set of radio parameters. The apparatus further includes a second deriving unit deriving a set of radio parameters so that an occupancy proportion of the guard interval part in a single symbol specified by another set of radio parameters is equal to an occupancy proportion of the guard interval part in a single symbol specified by the other set of radio parameters.
    Type: Application
    Filed: April 21, 2006
    Publication date: February 5, 2009
    Applicant: NTT DOCOMO, INC.
    Inventors: Mamoru Sawahashi, Kenichi Higuchi, Hiroyuki Atarashi, Motohiro Tanno, Yoshihisa Kishiyama, Yoshiaki Ofuji
  • Patent number: 7486638
    Abstract: A base station includes an acquisition unit for acquiring a packet transmitted from a terminal device to a mobile station, a priority calculation unit for calculating priority of transmission of the packet acquired by the acquisition unit to the mobile station, a weight processing unit for conducting weighting on the priority of the packet calculated by the priority calculation unit, a channel control unit for assigning a channel for transmission of the packet to the mobile station, to the packet based on the priority of the packet weighted by the weight processing unit, and a transmission unit for transmitting the packet to the mobile station on the channel assigned by the channel control unit.
    Type: Grant
    Filed: January 29, 2003
    Date of Patent: February 3, 2009
    Assignee: NTT DoCoMo, Inc.
    Inventors: Yoshiaki Ofuji, Sadayuki Abeta, Mamoru Sawahashi
  • Patent number: 7194266
    Abstract: When a handover standby threshold falls below a received power of perch channel from a base station 150-1 of a communication partner, a mobile station 110 sends a handover standby operation request to a base station control apparatus 130, and notifies of history of movement of itself and receives powers of perch channels from base stations 150-2–150-4 surrounding the communication partner (mobile station information). The base station control apparatus 130 compares the mobile station information with history of mobile station information so that a handover destination candidate base station is selected and sent to the mobile station 110. The mobile station 110 switches the communication partner to the handover destination candidate base station when received power of the perch channel from the base station 150-1 falls below a handover threshold.
    Type: Grant
    Filed: February 1, 2002
    Date of Patent: March 20, 2007
    Assignee: NTT DoCoMo, Inc.
    Inventors: Yoshihiro Ishikawa, Yoshiaki Ofuji, Seizo Onoe, Takehiro Nakamura, Mikio Iwamura, Takahiro Hayashi
  • Patent number: 7167718
    Abstract: A transmission power control apparatus for a wireless communication apparatus which reduces a power value of a signal input to a power amplifier to the maximum allowable input power value of the power amplifier or below is provided in which the transmission power control apparatus includes: a part for setting a transmission power upper limit value of a call according to a circuit type of the call; and a part for reducing transmission power for the call to the transmission power upper limit value or below.
    Type: Grant
    Filed: January 18, 2002
    Date of Patent: January 23, 2007
    Assignee: NTT DoCoMo, Inc.
    Inventors: Takahiro Hayashi, Yoshihiro Ishikawa, Seizo Onoe, Takehiro Nakamura, Mikio Iwamura, Yoshiaki Ofuji
  • Patent number: 7136624
    Abstract: An object is to select destination mobile stations so as to prevent directional beams directed to the respective mobile stations from interfering with each other in application of a directional antenna, and to allocate the radio resources to the mobile stations thus selected.
    Type: Grant
    Filed: February 5, 2003
    Date of Patent: November 14, 2006
    Assignee: NTT DoCoMo, Inc.
    Inventors: Yoshiaki Ofuji, Sadayuki Abeta, Mamoru Sawahashi
  • Patent number: 7120446
    Abstract: In resource measurement device 32, a measured value x of resource use condition is acquired in respect of the wireless resource to be monitored. Furthermore, in comparators 34 and 35, the measured value x is compared with the call admission threshold value xA of service A or with the call admission threshold value xB of service B, respectively. Comparison result selector 36 then selects one or other of the comparison results of comparators 34 and 35 in accordance with the type or degree of priority of the service of the call requested, identified by service identifier 33, and call admission control device 31 restricts new call admission in accordance with the selected comparison result. Thus, the call admission control method, communication system and base station device wherein deterioration of communication quality is suitably suppressed by call admission control in accordance with the service that is being utilized are provided in communication in which access is performed with shared resources.
    Type: Grant
    Filed: January 25, 2002
    Date of Patent: October 10, 2006
    Assignee: NTT DoCoMo, Inc.
    Inventors: Mikio Iwamura, Yoshihiro Ishikawa, Seizo Onoe, Takehiro Nakamura, Takahiro Hayashi, Yoshiaki Ofuji
  • Patent number: 7103364
    Abstract: Priority is given to handover calls over new calls in a mobile communications system using the CDMA method. This is achieved by rejecting requests for new calls in any one of the cases in which: an uplink interference amount estimated if the requested call is accepted exceeds an interference threshold level; a downlink total transmission power estimated if the requested call is accepted exceeds a downlink transmission power threshold; and an amount of spread code resources estimated if the requested call is accepted is lower than a spread code threshold.
    Type: Grant
    Filed: February 1, 2002
    Date of Patent: September 5, 2006
    Assignee: NTT DoCoMo, Inc.
    Inventors: Yoshihiro Ishikawa, Yoshiaki Ofuji, Seizo Onoe, Takehiro Nakamura, Mikio Iwamura, Takahiro Hayashi
  • Patent number: 7024191
    Abstract: For detecting service carriers, a received power measuring section initially carries out received power measurement in a frequency band assigned to the system, a frequency limiting section limits a service carrier seeking frequency range to the vicinity of a frequency where thus measured received power exceeds a threshold, the received power measuring section measures the received power at a frequency where a service carrier may exist within this frequency range, and the controller chooses a frequency yielding a high measured received power as a service carrier candidate frequency. Then, the cell search executing section initially executes a cell search for this candidate frequency.
    Type: Grant
    Filed: August 9, 2002
    Date of Patent: April 4, 2006
    Assignee: NTT DoCoMo, Inc.
    Inventors: Yoshiaki Ofuji, Motohiro Tanno, Takehiro Nakamura
  • Patent number: 6944439
    Abstract: An apparatus for controlling call admission, comprising a call admission check unit which determines whether to admit a call in response to reception of the call based on a threshold that reflect history of base station transmission power.
    Type: Grant
    Filed: February 8, 2002
    Date of Patent: September 13, 2005
    Assignee: NTT DoCoMo, Inc.
    Inventors: Takahiro Hayashi, Yoshihiro Ishikawa, Seizo Onoe, Takehiro Nakamura, Mikio Iwamura, Yoshiaki Ofuji
  • Publication number: 20050063392
    Abstract: An apparatus for packet-priority control for controlling a priority for packets input includes packet-priority setting means for setting hierarchically the priority for the packet input based on predetermined elements, and to adjust, taking into account other elements according to which the priority for the packet varies over time, the set priority, and wireless-resource allocating means for determining a packet for which a wireless resource is to be allocated in accordance with the adjusted priority.
    Type: Application
    Filed: September 2, 2004
    Publication date: March 24, 2005
    Applicant: NTT DoCoMo, Inc.
    Inventors: Yoshiaki Ofuji, Sadayuki Abeta, Mamoru Sawahashi
  • Publication number: 20030181163
    Abstract: An object is to select destination mobile stations so as to prevent directional beams directed to the respective mobile stations from interfering with each other in application of a directional antenna, and to allocate the radio resources to the mobile stations thus selected.
    Type: Application
    Filed: February 5, 2003
    Publication date: September 25, 2003
    Applicant: NTT DoCoMo, Inc.
    Inventors: Yoshiaki Ofuji, Sadayuki Abeta, Mamoru Sawahashi
  • Publication number: 20030142658
    Abstract: A base station includes an acquisition unit for acquiring a packet transmitted from a terminal device to a mobile station, a priority calculation unit for calculating priority of transmission of the packet acquired by the acquisition unit to the mobile station, a weight processing unit for conducting weighting on the priority of the packet calculated by the priority calculation unit, a channel control unit for assigning a channel for transmission of the packet to the mobile station, to the packet based on the priority of the packet weighted by the weight processing unit, and a transmission unit for transmitting the packet to the mobile station on the channel assigned by the channel control unit.
    Type: Application
    Filed: January 29, 2003
    Publication date: July 31, 2003
    Applicant: NTT DoCoMo, Inc.
    Inventors: Yoshiaki Ofuji, Sadayuki Abeta, Mamoru Sawahashi
  • Publication number: 20030032441
    Abstract: For detecting service carriers, a received power measuring section initially carries out received power measurement in a frequency band assigned to the system, a frequency limiting section limits a service carrier seeking frequency range to the vicinity of a frequency where thus measured received power exceeds a threshold, the received power measuring section measures the received power at a frequency where a service carrier may exist within this frequency range, and the controller chooses a frequency yielding a high measured received power as a service carrier candidate frequency. Then, the cell search executing section initially executes a cell search for this candidate frequency.
    Type: Application
    Filed: August 9, 2002
    Publication date: February 13, 2003
    Applicant: NTT DoCoMo, Inc
    Inventors: Yoshiaki Ofuji, Motohiro Tanno, Takehiro Nakamura
  • Publication number: 20020119779
    Abstract: When a handover standby threshold falls below a received power of perch channel from a base station 150-1 of a communication partner, a mobile station 110 sends a handover standby operation request to a base station control apparatus 130, and notifies of history of movement of itself and receives powers of perch channels from base stations 150-2 -150-4 surrounding the communication partner (mobile station information). The base station control apparatus 130 compares the mobile station information with history of mobile station information so that a handover destination candidate base station is selected and sent to the mobile station 110. The mobile station 110 switches the communication partner to the handover destination candidate base station when received power of the perch channel from the base station 150-1 falls below a handover threshold.
    Type: Application
    Filed: February 1, 2002
    Publication date: August 29, 2002
    Applicant: NTT DoCoMo, Inc.
    Inventors: Yoshihiro Ishikawa, Yoshiaki Ofuji, Seizo Onoe, Takehiro Nakamura, Mikio Iwamura, Takahiro Hayashi
  • Publication number: 20020115427
    Abstract: An apparatus for controlling call admission, comprising a call admission check unit which determines whether to admit a call in response to reception of the call based on a threshold that reflect history of base station transmission power.
    Type: Application
    Filed: February 8, 2002
    Publication date: August 22, 2002
    Applicant: NTT DoCoMo, Inc.
    Inventors: Takahiro Hayashi, Yoshihiro Ishikawa, Seizo Onoe, Takehiro Nakamura, Mikio Iwamura, Yoshiaki Ofuji
  • Publication number: 20020110090
    Abstract: Resource measurement device 32 acquires a measured value x of the resource use condition in transmitting/receiving section 20 in respect of the wireless resource that is the subject of monitoring. Also, correction value calculation device 33 calculates a correction value in accordance with the number of packet users at transmitting/receiving section 20 and adjustment device 34 adjusts the call acceptance threshold value xc using the correction value, so as to obtain a corrected threshold value xc′. Comparator 35 then compares the measured value of the resource use condition x and the corrected threshold value xc′ and outputs the comparison result to call acceptance control device 31. If x≧xc′, call acceptance control device 31 restricts acceptance of new calls.
    Type: Application
    Filed: January 15, 2002
    Publication date: August 15, 2002
    Applicant: NTT DoCoMo, Inc.
    Inventors: Mikio Iwamura, Yoshihiro Ishikawa, Seizo Onoe, Takehiro Nakamura, Takahiro Hayashi, Yoshiaki Ofuji
  • Publication number: 20020107021
    Abstract: Priority is given to handover calls over new calls in a mobile communications system using the CDMA method. This is achieved by rejecting requests for new calls in any one of the cases in which: an uplink interference amount estimated if the requested call is accepted exceeds an interference threshold level; a downlink total transmission power estimated if the requested call is accepted exceeds a downlink transmission power threshold; and an amount of spread code resources estimated if the requested call is accepted is lower than a spread code threshold.
    Type: Application
    Filed: February 1, 2002
    Publication date: August 8, 2002
    Applicant: NTT DoCoMo, Inc
    Inventors: Yoshihiro Ishikawa, Yoshiaki Ofuji, Seizo Onoe, Takehiro Nakamura, Mikio Iwamura, Takahiro Hayashi
  • Publication number: 20020102986
    Abstract: In resource measurement device 32, a measured value x of resource use condition is acquired in respect of the wireless resource to be monitored. Furthermore, in comparators 34 and 35, the measured value x is compared with the call admission threshold value xA of service A or with the call admission threshold value xB of service B, respectively. Comparison result selector 36 then selects one or other of the comparison results of comparators 34 and 35 in accordance with the type or degree of priority of the service of the call requested, identified by service identifier 33, and call admission control device 31 restricts new call admission in accordance with the selected comparison result. Thus, the call admission control method, communication system and base station device wherein deterioration of communication quality is suitably suppressed by call admission control in accordance with the service that is being utilized are provided in communication in which access is performed with shared resources.
    Type: Application
    Filed: January 25, 2002
    Publication date: August 1, 2002
    Applicant: NTT DoCoMo, Inc.
    Inventors: Mikio Iwamura, Yoshihiro Ishikawa, Seizo Onoe, Takehiro Nakamura, Takahiro Hayashi, Yoshiaki Ofuji