Patents by Inventor Motohiro Tanno

Motohiro Tanno 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: 20090129322
    Abstract: A mobile station includes: a QoS (quality of service) requirement determination unit configured to determine a QoS requirement for a data packet; a downlink channel condition estimation unit configured to estimate a downlink channel condition; an identification number extracting unit configured to extract an identification number for the mobile station; and a notification unit configured to notify a base station of the QoS requirement, the identification number for the mobile station, and the downlink channel condition by means of a reservation packet. A base station includes: an uplink channel condition estimation unit configured to estimate an uplink channel condition by means of a reservation packet; a radio parameter control unit configured to determine and control a radio parameter based on the reservation packet and the uplink channel condition.
    Type: Application
    Filed: April 10, 2006
    Publication date: May 21, 2009
    Applicant: NTT DOCOMO, INC.
    Inventors: Shingo Suwa, Motohiro Tanno, 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: 7437156
    Abstract: A mobile communication system is provided for decreasing power consumption in a mobile station. In the mobile communication system, a base station or a radio network control apparatus sets a threshold of signal energy to noise power density ratio of a common pilot signal according to downlink total sending power, which may change every moment, and sends the threshold to the mobile station 110. The mobile station 110 measures the ratio, and omits surrounding cell measurement when the measured ratio exceeds the threshold.
    Type: Grant
    Filed: August 27, 2002
    Date of Patent: October 14, 2008
    Assignee: NTT DoCoMo, Inc.
    Inventors: Motohiro Tanno, Takehiro Nakamura
  • Patent number: 7315566
    Abstract: A mobile communication system 1 according to the present invention comprises base station 30 and mobile station 10. The base station 30 sends a pilot symbol sequence known to the mobile station 10, to the mobile station 10, using a plurality of carriers for downward channels, and performs communication with the mobile station 10 while multiplying the channels by frequencywise same scrambling codes every symbol period. The mobile station 10 is provided with a peak detector 17 for calculating cross correlation allowing for a phase difference of the scrambling codes, between frequencywise pilot symbol sequences received from the base station 30, thereby detecting a radio frame boundary.
    Type: Grant
    Filed: February 14, 2003
    Date of Patent: January 1, 2008
    Assignee: NTT DoCoMo, Inc.
    Inventors: Motohiro Tanno, Hiroyuki Atarashi, Mamoru Sawahashi
  • Patent number: 7170875
    Abstract: The present invention provides a cell search method that can reduce the power consumption of a mobile station. At a first step, averaging is executed over an averaging time T1, and slot boundaries are then detected. Next, as in conventional examples, a second and a third step are serially executed, and the averaging at the first step continues to be executed concurrently with the operation of the second and third steps. Correlation values for slots over an averaging time T1? are averaged, and the averaging is further executed using an already calculated first-step average correlation value, thereby calculating an average correlation value.
    Type: Grant
    Filed: September 18, 2001
    Date of Patent: January 30, 2007
    Assignee: NTT DoCoMo, Inc.
    Inventors: Motohiro Tanno, Takehiro Nakamura
  • 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: 7012909
    Abstract: The present invention increases the detection accuracy of each of a first to a third steps of cell search to reduce the time required for detecting correct frame boundaries and scramble code. A mobile station inputs a received signal to a matched filter corresponding to a primary synchronization code PSC, and a multi-slot averaging section executes averaging over a plurality of slots in order to reduce the adverse effects of noise and interference. After the averaging over the plurality of slots, a multi-search averaging section further executes averaging over a plurality of searches. Subsequently, a peak detector selects a timing with which an average correlation value is largest, to detect slot boundaries.
    Type: Grant
    Filed: August 31, 2001
    Date of Patent: March 14, 2006
    Assignee: NTT DoCoMo, Inc.
    Inventors: Motohiro Tanno, Takehiro Nakamura
  • Patent number: 6961565
    Abstract: The present invention reduces the time required for cell search and increase the accuracy of the cell search by determining, during selection of frame boundaries and a scramble code, whether or not the selection results are correct. A mobile station causes descramblers to descramble a received signal with eight scramble codes. Then, correlators calculate the phases of the scramble codes on the basis of frame boundaries, and despreads the signal with a spreading code for a CPICH. The mobile station performs this operation over a plurality of symbols, and causes averaging process sections to average the results. Then, a peak detector selects a scramble code with which an average correlation coefficient is largest. This maximum average correlation coefficient is output to a detection results judging section, which then calculates the ratio of this value to a reference value calculated inside the mobile station, thereby judging detection results.
    Type: Grant
    Filed: September 18, 2001
    Date of Patent: November 1, 2005
    Assignee: NTT DoCoMo, Inc.
    Inventors: Motohiro Tanno, Takehiro Nakamura
  • Patent number: 6950455
    Abstract: A synchronization establishing method of a mobile station in a mobile communication system is proposed which can reduce the effect of noise or interference, and achieve higher accuracy than conventional method. To enable the mobile station to detect a signal transmitted from a base station, and to establish synchronization to the signal in a mobile communication system in which a synchronization channel is multiplexed periodically into the downlink signal, the mobile station averages, in phase and in complex numbers, correlation values of the synchronization channel over a plurality of periods, followed by detecting the power of them to carrying out peak detection.
    Type: Grant
    Filed: June 13, 2001
    Date of Patent: September 27, 2005
    Assignee: NTT DoCoMo, Inc.
    Inventors: Motohiro Tanno, Takehiro Nakamura
  • Publication number: 20050190737
    Abstract: A mobile station and a base station are disclosed. The mobile station, when transmitting a reservation request signal and a data packet, controls radio parameters of reservation request signal transmission and data packet transmission so that communication quality required by the data packet transmission is satisfied, and system capacity is maximized. Further, the mobile station transmits the reservation request signal and data packet, the radio parameters of which are controlled, to the base station.
    Type: Application
    Filed: February 7, 2005
    Publication date: September 1, 2005
    Applicant: NTT DoCoMo, Inc.
    Inventors: Motohiro Tanno, Yousuke Iizuka, Mamoru Sawahashi
  • Publication number: 20030152178
    Abstract: A mobile communication system 1 according to the present invention comprises base station 30 and mobile station 10. The base station 30 sends a pilot symbol sequence known to the mobile station 10, to the mobile station 10, using a plurality of carriers for downward channels, and performs communication with the mobile station 10 while multiplying the channels by frequencywise same scrambling codes every symbol period. The mobile station 10 is provided with a peak detector 17 for calculating cross correlation allowing for a phase difference of the scrambling codes, between frequencywise pilot symbol sequences received from the base station 30, thereby detecting a radio frame boundary.
    Type: Application
    Filed: February 14, 2003
    Publication date: August 14, 2003
    Applicant: NTT DoCoMo, Inc.
    Inventors: Motohiro Tanno, Hiroyuki Atarashi, Mamoru Sawahashi
  • Publication number: 20030045320
    Abstract: A mobile communication system is provided for decreasing power consumption in a mobile station. In the mobile communication system, a base station or a radio network control apparatus sets a threshold of signal energy to noise power density ratio of a common pilot signal according to downlink total sending power, which may change every moment, and sends the threshold to the mobile station 110. The mobile station 110 measures the ratio, and omits surrounding cell measurement when the measured ratio exceeds the threshold.
    Type: Application
    Filed: August 27, 2002
    Publication date: March 6, 2003
    Applicant: NTT DoCoMo, Inc.
    Inventors: Motohiro Tanno, Takehiro Nakamura
  • 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: 20020041579
    Abstract: The present invention provides a cell search method that can reduce the power consumption of a mobile station. At a first step, averaging is executed over an averaging time T1, and slot boundaries are then detected. Next, as in conventional examples, a second and a third step are serially executed, and the averaging at the first step continues to be executed concurrently with the operation of the second and third steps. Correlation values for slots over an averaging time T1′ are averaged, and the averaging is further executed using an already calculated first-step average correlation value, thereby calculating an average correlation value.
    Type: Application
    Filed: September 18, 2001
    Publication date: April 11, 2002
    Inventors: Motohiro Tanno, Takehiro Nakamura
  • Publication number: 20020034944
    Abstract: The present invention reduces the time required for cell search and increase the accuracy of the cell search by determining, during selection of frame boundaries and a scramble code, whether or not the selection results are correct. A mobile station causes descramblers to descramble a received signal with eight scramble codes. Then, correlators calculate the phases of the scramble codes on the basis of frame boundaries, and despreads the signal with a spreading code for a CPICH. The mobile station performs this operation over a plurality of symbols, and causes averaging process sections to average the results. Then, a peak detector selects a scramble code with which an average correlation coefficient is largest. This maximum average correlation coefficient is output to a detection results judging section, which then calculates the ratio of this value to a reference value calculated inside the mobile station, thereby judging detection results.
    Type: Application
    Filed: September 18, 2001
    Publication date: March 21, 2002
    Inventors: Motohiro Tanno, Takehiro Nakamura
  • Publication number: 20020027898
    Abstract: The present invention increases the detection accuracy of each of a first to a third steps of cell search to reduce the time required for detecting correct frame boundaries and scramble code. A mobile station inputs a received signal to a matched filter corresponding to a primary synchronization code PSC, and a multi-slot averaging section executes averaging over a plurality of slots in order to reduce the adverse effects of noise and interference. After the averaging over the plurality of slots, a multi-search averaging section further executes averaging over a plurality of searches. Subsequently, a peak detector selects a timing with which an average correlation value is largest, to detect slot boundaries.
    Type: Application
    Filed: August 31, 2001
    Publication date: March 7, 2002
    Inventors: Motohiro Tanno, Takehiro Nakamura
  • Publication number: 20010053191
    Abstract: A synchronization establishing method of a mobile station in a mobile communication system is proposed which can reduce the effect of noise or interference, and achieve higher accuracy than conventional method. To enable the mobile station to detect a signal transmitted from a base station, and to establish synchronization to the signal in a mobile communication system in which a synchronization channel is multiplexed periodically into the downlink signal, the mobile station averages, in phase and in complex numbers, correlation values of the synchronization channel over a plurality of periods, followed by detecting the power of them to carrying out peak detection.
    Type: Application
    Filed: June 13, 2001
    Publication date: December 20, 2001
    Inventors: Motohiro Tanno, Takehiro Nakamura
  • Patent number: 6310868
    Abstract: A CDMA communications system that can shorten a delay time until the establishment of traffic, and prevent excessive transmission power. Although transmission request signals RQ1, RQ2, RQ3, . . . sent from mobile stations through a common channel undergo only open loop power transmission control, and hence have large fluctuations in their received levels, their interference amount to message signals can be kept low because their received power is averagely about 1/a of that of the message signals MSG1, MSG2, MSG3, . . . The message signals are sent from the mobile stations in accordance with the power transmission control bits contained in a forward link signal ACK sent from the base station, followed by closed loop power transmission control. This enables the received level fluctuations at the base station to be kept low.
    Type: Grant
    Filed: February 12, 1998
    Date of Patent: October 30, 2001
    Assignee: NTT Mobile Communications Network Inc.
    Inventors: Shinji Uebayashi, Motohiro Tanno
  • Publication number: 20010012284
    Abstract: A CDMA communications system that can shorten a delay time until the establishment of traffic, and prevent excessive transmission power. Although transmission request signals RQ1, RQ2, RQ3, . . . sent from mobile stations through a common channel undergo only open loop power transmission control, and hence have large fluctuations in their received levels, their interference amount to message signals can be kept low because their received power is averagely about 1/a of that of the message signals MSG1, MSG2, MSG3, . . . The message signals are sent from the mobile stations in accordance with the power transmission control bits contained in a forward link signal ACK sent from the base station, followed by closed loop power transmission control. This enables the received level fluctuations at the base station to be kept low.
    Type: Application
    Filed: February 12, 1998
    Publication date: August 9, 2001
    Inventors: SHINJI UEBAYASHI, MOTOHIRO TANNO
  • Patent number: 6208624
    Abstract: A paging scheme for a mobile communication system which is capable of suppressing the power consumption of the mobile station by reducing the intermittent ratio while keeping an average time required for the paging shorter than a case of merely increasing a number of time-slots. Each base station transmits a paging channel on which a paging signal for each mobile station is transmitted at intermittent timings, where the paging channel has a data transmission rate higher than a required paging channel rate of the mobile communication system, so as to shorten a transmission time of the paging signal for each mobile station. Then, each mobile station judges a presence or absence of the paging signal for that mobile station by receiving the paging channel at these intermittent timings. The paging channel may have a data transmission rate which is variable.
    Type: Grant
    Filed: November 13, 1997
    Date of Patent: March 27, 2001
    Assignee: NTT Mobile Communications Network Inc.
    Inventors: Motohiro Tanno, Takehiro Nakamura, Seizo Onoe