Patents by Inventor Sadayuki Abeta

Sadayuki Abeta 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: 20120003995
    Abstract: A radio base station according to the present invention includes: a downlink data resumption processing unit configured to transmit an RA preamble assignment signal to a mobile station, when a positioning trigger is detected in a state in which no synchronization is established in an uplink between the radio base station and the mobile station; and a propagation delay calculation unit configured to calculate propagation delay in the uplink, in response to reception of a RA preamble assigned by the RA preamble assignment signal.
    Type: Application
    Filed: March 4, 2010
    Publication date: January 5, 2012
    Applicant: NTT DOCOMO, INC.
    Inventors: Minami Ishii, Sadayuki Abeta
  • Publication number: 20120003977
    Abstract: A mobile communication method according to the present invention includes steps of: performing, at a mobile station (UE) having established a first connection in a first cell, a cell selection process when detecting failure in the first connection; transmitting, from the mobile station (UE) to a second cell selected by the cell selection process, a connection re-establishment request signal; determining, at the radio base station managing the second cell, whether or not to have stored context information of the mobile station (UE) having transmitted the connection re-establishment request signal; acquiring, at the radio base station managing the second cell, the context information of the mobile station from a radio base station managing the first cell, when the radio base station managing the second cell determines that it does not store the context information of the mobile station (UE).
    Type: Application
    Filed: February 2, 2010
    Publication date: January 5, 2012
    Applicant: NTT DOCOMO, Inc.
    Inventors: Mikio Iwamura, Sadayuki Abeta
  • Publication number: 20110317745
    Abstract: In a mobile communication system according to the present invention, a reference signal sequence includes a plurality of signal sequences assigned in slot units in the predetermined physical channel based on a hopping pattern and a sequence shift pattern; the hopping pattern is configured to be determined based on a slot number and an SFN in the predetermined physical channel or the predetermined physical signal; the sequence shift pattern is configured to be determined based on the identification information of the cell to which the predetermined physical channel or the predetermined physical signal has been set; and the hopping cycle is configured to be determined based on a cycle of the slot number and an SFN cycle.
    Type: Application
    Filed: December 24, 2009
    Publication date: December 29, 2011
    Applicant: NTT DOCOMO, INC.
    Inventors: Naoto Okubo, Hiroyuki Ishii, Sadayuki Abeta, Yoshihisa Kishiyama
  • Patent number: 8085661
    Abstract: A control channel allocation apparatus includes a memory portion that stores an identifier indicating a layer 1 control channel associated with a downlink data channel, and a physical channel parameter for transmitting an uplink layer 1 control channel, the identifier being related to the physical channel parameter; a physical layer parameter determination portion that determines the physical channel parameter for transmitting the uplink layer 1 control channel in accordance with the identifier; a layer 1 control channel generation portion that generates a layer 1 control channel indicating a decoding result of a data channel, in accordance with the determined physical channel parameter; and a transmission portion that transmits the generated layer 1 control channel.
    Type: Grant
    Filed: November 10, 2006
    Date of Patent: December 27, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Atsushi Harada, Sadayuki Abeta, Takehiro Nakamura
  • Patent number: 8085785
    Abstract: There is disclosed a mobile station performing packet communications with a base station, including: a reservation control signal generating unit configured to generate a reservation control signal, based on control information transmitted in advance of a data packet; and a reservation control signal transmission control unit configured to transmit the reservation control signal at a predetermined timing.
    Type: Grant
    Filed: April 13, 2006
    Date of Patent: December 27, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Motohiro Tanno, Sadayuki Abeta, Mamoru Sawahashi
  • Patent number: 8050228
    Abstract: In a retransmission control method, a transmitting-side apparatus manages an acknowledgement information reception window and the transmitting-side apparatus does not perform the window control processing and the retransmission control processing of a packet on the basis of the acknowledgement information for a sequence number of the packet which is included in the acknowledgement information received from the receiving-side apparatus, when the sequence number takes a value outside a range of the acknowledgement information reception window.
    Type: Grant
    Filed: April 4, 2008
    Date of Patent: November 1, 2011
    Assignee: NTT Docomo, Inc.
    Inventors: Anil Umesh, Sadayuki Abeta
  • Publication number: 20110261772
    Abstract: In a mobile communication system according to the present invention, a radio base station (eNB) is configured to transmit broadcast information including a parameter to which a frequency bandwidth used in the mobile communication system is set; a mobile station (UE#1) is configured to determine, when a predetermined value is set to the parameter included in the received broadcast information, that a first frequency bandwidth is the frequency bandwidth used in the mobile communication system; and a mobile station (UE#2) is configured to determine, when the predetermined value is set to the parameter included in the received broadcast information, that a second frequency bandwidth different from the first frequency bandwidth is the frequency bandwidth used in the mobile communication system.
    Type: Application
    Filed: October 28, 2009
    Publication date: October 27, 2011
    Applicant: NTT DOCOMO, INC.
    Inventors: Mikio Iwamura, Hiroyuki Ishii, Minami Ishii, Sadayuki Abeta
  • Patent number: 8014803
    Abstract: A disclosed mobile station includes a storage unit configured to establish a correspondence between an identifier for a downlink Layer-1 control channel associated with a downlink data channel and a physical channel parameter for an uplink Layer-1 control channel and to store the identifier and the physical channel parameter; and a unit configured to determine the physical channel parameter based on the identifier and generate the uplink Layer-1 control channel. A disclosed base station includes a storage unit; a unit configured to measure reception quality based on a signal transmitted from the mobile station, select the physical channel parameter and generate the downlink Layer-1 control channel corresponding to the physical channel parameter; and a transmitting unit configured to transmit control information on the generated downlink Layer-1 control channel.
    Type: Grant
    Filed: November 10, 2006
    Date of Patent: September 6, 2011
    Assignee: NTT DoCoMo, Inc
    Inventors: Atsushi Harada, Sadayuki Abeta, Takehiro Nakamura
  • Patent number: 8005063
    Abstract: A receiving apparatus receives control, pilot and data channels in an uplink. The apparatus includes a data-channel receiving unit for receiving the pilot channel in an antenna gain pattern of a multi-beam having multiple fixed directional beams with respectively different fixed directional directions or of a variable directional beam having a directional direction varying in accordance with the position of a mobile terminal; and a data-channel receiving unit for receiving the data channel in an antenna gain pattern of a multi-beam or a variable directional beam.
    Type: Grant
    Filed: March 20, 2006
    Date of Patent: August 23, 2011
    Assignee: NTT Docomo, Inc.
    Inventors: Nobuhiko Miki, Hiroyuki Atarashi, Sadayuki Abeta, Mamoru Sawahashi
  • Patent number: 8005110
    Abstract: The present invention provides a single carrier/DS-CDMA packet transmission method wherein a predetermined time slot is assigned to reservation demand packet transmission in regard to a spreading code, and the reservation demand packet and data packets are time-multiplexed for transmission. An uplink packet transmission method in a multi-carrier/DS-CDMA mobile communication system is also provided, wherein frames are set up in each communication channel of a subcarrier, time slots which are time-segments of the frames are set up further, and a mobile station spreads a packet to be transmitted by a spreading code and the information signal is transmitted to a base station in a predetermined time slot.
    Type: Grant
    Filed: August 13, 2007
    Date of Patent: August 23, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Koichi Okawa, Hiroyuki Atarashi, Sadayuki Abeta, Mamoru Sawahashi
  • Patent number: 8000300
    Abstract: A mobile station includes a radio channel condition evaluation unit evaluating a radio channel condition; a radio channel condition averaging unit averaging the evaluated radio channel condition over a predefined time period; a radio channel condition threshold storage unit storing a threshold of the radio channel condition and a message type, the threshold and the message type being specified by a radio access network apparatus; a radio channel condition comparison unit comparing the averaged radio channel condition with the threshold; and a radio channel condition reporting unit transmitting an identifier and the radio channel condition for a cell to the radio access network apparatus, the averaged radio channel condition of the cell being greater than or equal to the threshold.
    Type: Grant
    Filed: February 13, 2007
    Date of Patent: August 16, 2011
    Assignee: NTT Docomo, Inc.
    Inventors: Minami Ishii, Sadayuki Abeta, Takehiro Nakamura
  • Publication number: 20110149771
    Abstract: A mobile station (UE) according to the present invention includes: a CP length determiner unit (15) configured to determine a length of a CP to be inserted in an uplink signal; and a CP adder unit (14) configured to generate the uplink signal by adding a CP to any one of an inputted signal modulated by DFT-Spread OFDM (Single Carrier FDMA) scheme and an inputted signal modulated OFDM scheme, the CP having the length determined by the CP length determiner unit (15), wherein the cyclic prefix length determiner unit (15) is configured to be capable of setting the length of the CP to be inserted in the uplink signal independently of a length of a CP inserted in a downlink signal.
    Type: Application
    Filed: September 24, 2009
    Publication date: June 23, 2011
    Applicant: NTT DOCOMO, INC.
    Inventors: Sadayuki Abeta, Hiroyuki Ishii, Yoshihisa Kishiyama
  • Publication number: 20110149840
    Abstract: A transmitter (10) is provided with an MAC-PDU generating section (12), which multiplexes an information element and generates an MAC-PDU; and a first data unit transmitting section (13), which transmits the generated MAC-PDU, in an MAC layer. The information element is of an MAC-SDU received from an RLC layer, an MAC control block or padding. The MAC-PDU generating section (12) adds to an MAC-PDU an MAC header including a C/T for identifying the type of the information element to be multiplexed into the MAC-PDU and an LI for indicating the size of the information element.
    Type: Application
    Filed: December 27, 2007
    Publication date: June 23, 2011
    Applicant: NTT DOCOMO, INC.
    Inventors: Atsushi Harada, Minami Ishii, Sadayuki Abeta, Anil Umesh
  • Patent number: 7965640
    Abstract: A controlling method and a radio base station apparatus capable of variably determining a Transmission Time Interval (TTI) length in accordance with a communication environment of a mobile terminal is disclosed. The radio base station apparatus includes a receiving section receiving information via an uplink channel; and a scheduler variably determining a Transmission Time Interval (TTI) length for any one of an uplink shared channel and a downlink shared channel or both based on at least any of a moving speed of a mobile terminal, location of the mobile terminal in a cell, a provided throughput value, and a number of retransmissions obtained from the received information. Preferably, the scheduler includes a TTI length allocation table describing relationships between parameter values and the corresponding TTI length, the parameters being used for estimating the location and/or the moving speed of the mobile terminal.
    Type: Grant
    Filed: April 26, 2007
    Date of Patent: June 21, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Atsushi Harada, Minami Ishii, Sadayuki Abeta
  • Patent number: 7957755
    Abstract: A mobile station for establishing a signaling control channel and a shared data channel between a radio access network apparatus and the mobile station to perform communication includes discontinuous reception means configured to perform discontinuous reception of broadcast information using the signaling control channel, shared data channel reception determination means configured to determine whether to receive the shared data channel based on an item of broadcast information and information indicating presence or absence of change of content corresponding to the item of the broadcast information that are transmitted by the signaling control channel, and shared data channel reception means configured to receive the shared data channel according to the determination.
    Type: Grant
    Filed: October 23, 2006
    Date of Patent: June 7, 2011
    Assignee: NTT Docomo, Inc.
    Inventors: Minami Ishii, Sadayuki Abeta, Takehiro Nakamura
  • Patent number: 7944850
    Abstract: A base station performing a radio communication with a user equipment includes a transmission format determining unit configured to determine a transmission format of a downlink data channel not to be associated by a control channel, based on a downlink reception signal quality measured by the user equipment, a notification unit configured to notify, to the user equipment, the transmission format determined by the transmission format determining unit, and a transmitting unit configured to transmit downlink data to the user equipment via the downlink data channel, by using the transmission format determined by the transmission format determining unit.
    Type: Grant
    Filed: June 19, 2007
    Date of Patent: May 17, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Atsushi Harada, Minami Ishii, Sadayuki Abeta
  • Publication number: 20110002235
    Abstract: A disclosed base station includes a transmission-rate determining unit for determining a transmission rate of a control channel for transmitting an upper-layer control signal, and a transmitter for allocating a predetermined bandwidth to the control channel for transmitting the upper-layer control signal according to the determined transmission rate, and transmitting the signal.
    Type: Application
    Filed: September 10, 2010
    Publication date: January 6, 2011
    Applicant: NTT DOCOMO, INC.
    Inventors: Sadayuki Abeta, Motohiro Tanno, Nobuhiko Miki, Mamoru Sawahashi
  • Patent number: 7864739
    Abstract: The object of the present invention is to provide a transmitter for multi-carrier transmission for allocating pilot channels to radio frames, in consideration of interference with other pilot channels. The present invention relates to the transmitter for multi-carrier transmission configured to transmit a plurality of sub-carriers having at least one pilot symbol duration. The transmitter according to the present invention comprises a pilot symbol allocater configured to allocate a plurality of pilot symbol patterns which are orthogonal to each other, to the at least one pilot symbol durations in at least two sub-carriers.
    Type: Grant
    Filed: May 14, 2003
    Date of Patent: January 4, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Hiroyuki Atarashi, Sadayuki Abeta, Noriyuki Maeda, Mamoru Sawahashi
  • Publication number: 20100291956
    Abstract: One feature of the present invention relates to a base station for operating multiple cells each having a predefined bandwidth, including: a load measurement unit configured to measure traffic status in each of the cells; a selection probability computation unit configured to compute a selection probability used to select a preselected cell based on the traffic status, the preselected cell being accessed by a mobile station in transition from an idle state to an active state; a transmission unit configured to transmit the selection probability; and a control plane control unit configured to connect to the preselected cell being accessed by the mobile station.
    Type: Application
    Filed: August 14, 2007
    Publication date: November 18, 2010
    Applicant: NTT DOCOMO, INC.
    Inventors: Mikio Iwamura, Minami Ishii, Yasuhiro Kato, Sadayuki Abeta
  • Publication number: 20100293427
    Abstract: A radio communications apparatus having a retransmission function that has a determination portion configured to receive an error detection result obtained for a first packet transmitted to a destination apparatus and determine in a first sub-layer whether the error detection result is a positive acknowledgement; a transmission portion configured to transmit a second packet following the first packet to the destination apparatus; a timer portion configured to measure a predetermined period of time after the second packet is transmitted; and a report portion configured to report to a second sub-layer that is an upper sub-layer of the first sub-layer that the error detection result is the positive acknowledgement when no message is received from the destination apparatus during the predetermined period of time, the message indicating that the error detection result is falsely determined to be the positive acknowledgement.
    Type: Application
    Filed: June 15, 2007
    Publication date: November 18, 2010
    Applicant: NTT DOCOMO, INC.
    Inventors: Anil Umesh, Sadayuki Abeta