Patents by Inventor Mikio Iwamura

Mikio Iwamura 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: 10182393
    Abstract: A method is described for controlling a small cell base station in a wireless communication system having a plurality of small cell base stations controlled by a macro base station. The method includes taking, by a small cell base station, a measurement for obtaining information describing a vicinity around the small cell base station and reporting the information from the small cell base station to the macro base station.
    Type: Grant
    Filed: May 27, 2016
    Date of Patent: January 15, 2019
    Assignee: NTT DOCOMO, INC.
    Inventors: Patrick Agyapong, Emmanuel Ternon, Liang Hu, Katsutoshi Kusume, Mikio Iwamura
  • Publication number: 20180375704
    Abstract: How to apply an Alamouti like space-time coding (or transmit diversity) to a Filter Bank Multicarrier (FBMC) transmission using Offset QAM (OQAM). In FBMC, due to the orthogonality in the real domain only, an intrinsic interference results thereof for the imaginary component. Simply adapting the Alamouti scheme to FBMC OQAM is not obvious since the intrinsic interference terms are not equivalent at each antenna since it depends on the surrounding symbols. The application proposes to use a precoding symbol chosen to cancel out (zero) the intrinsic interference individually for each antenna, ie a code rate of ½ (sending one data symbol requires two time units). A more elaborated embodiment proposes to choose the contiguous precoding symbols such that a virtual QAM Alamouti scheme is achieved, without rate loss.
    Type: Application
    Filed: April 1, 2016
    Publication date: December 27, 2018
    Applicant: NTT DOCOMO, INC.
    Inventors: Petra Weitkemper, Katsutoshi Kusume, Jamal Bazzi, Mikio Iwamura
  • Publication number: 20180367353
    Abstract: How to apply an Alamouti like space-time coding (or transmit diversity) to a Filter Bank Multicarrier (FBMC) transmission using Offset QAM (OQAM). In FBMC, due to the orthogonality in the real domain only, an intrinsic interference results thereof for the imaginary component. Simply adapting the Alamouti scheme to FBMC OQAM is not obvious since the intrinsic interference terms are not equivalent at each antenna since it depends on the surrounding symbols. The application proposes to choose contiguous precoding symbols such that a virtual PAM Alamouti scheme is achieved. Code rates of 1/2 or 2/3 are achieved depending on the number of precoding symbols needed per antenna.
    Type: Application
    Filed: April 1, 2016
    Publication date: December 20, 2018
    Applicant: NTT DOCOMO, INC.
    Inventors: Petra Weitkemper, Katsutoshi Kusume, Jamal Bazzi, Mikio Iwamura
  • Patent number: 10085186
    Abstract: A method is described for controlling a user equipment to be served by a small cell base station in a wireless communication system including a plurality of small cell base stations controlled by a macro base station. The method includes signaling, by the small cell base station, the small cell base station capabilities to the macro base station; signaling, by the user equipment, the user equipment capabilities to the macro base station; and signaling, by the macro base station, a small cell base station configuration to the user equipment.
    Type: Grant
    Filed: May 27, 2016
    Date of Patent: September 25, 2018
    Assignee: NTT DOCOMO, INC.
    Inventors: Patrick Agyapong, Emmanuel Ternon, Liang Hu, Katsutoshi Kusume, Mikio Iwamura
  • Patent number: 10003992
    Abstract: A method is described for controlling a small cell base station and a user equipment to be served by the small base station in a wireless communication system having a plurality of small cell base stations controlled by a macro base station. The method has, in response to a request from the macro base station to the small cell base station, performing, by the small cell base station, a beacon transmission on one or more resources, in response to a request from the macro base station to the user equipment, performing, by the user equipment, a channel quality measurement on the one or more resources, and reporting the measured channel quality from the user equipment to the macro base station.
    Type: Grant
    Filed: May 27, 2016
    Date of Patent: June 19, 2018
    Assignee: NTT DOCOMO, INC.
    Inventors: Patrick Agyapong, Emmanuel Ternon, Liang Hu, Katsutoshi Kusume, Mikio Iwamura
  • Patent number: 9999031
    Abstract: To further notify the amount of data retained in the transmission buffer used in a communication among a plurality of MOBILE STATIONs to a RADIO BASE STATION, the mobile communication method according to the present invention includes: transmitting, with a MOBILE STATION (UE#1), a BSR (#1) indicating the amount of data retained in a transmission buffer corresponding to a logical channel in a Uu interface to a RADIO BASE STATION (eNB); transmitting, with a MOBILE STATION (UE1), a BSR (#2) indicating the amount of data retained in a transmission buffer corresponding to a logical channel in a Ud interface to the RADIO BASE STATION (eNB); and distinguishing, with the RADIO BASE STATION (eNB), the BSR (#1) from the BSR (#2) based on predetermined information included in the received BSR.
    Type: Grant
    Filed: October 22, 2015
    Date of Patent: June 12, 2018
    Assignee: NTT DOCOMO, INC.
    Inventors: Mikio Iwamura, Tooru Uchino
  • Patent number: 9894566
    Abstract: A mobile communication method involving performing, at a mobile station UE which establishes a first connection in a first cell, a cell selection process at the time of detecting a failure in the first connection, transmitting, from the mobile station UE to a second cell selected in the cell selection process, a connection re-establishment request signal, determining, at a radio base station that manages the second cell, whether or not to store context information of the mobile station UE in response to the connection re-establishment request signal, acquiring, at the radio base station, the context information of the mobile station UE from a radio base station that manages the first cell, when determining that the context information of the mobile station UE is not stored, and establishing a second connection in the second cell for the mobile station UE, based on the context information of the mobile station UE.
    Type: Grant
    Filed: December 10, 2009
    Date of Patent: February 13, 2018
    Assignee: NTT DOCOMO, INC.
    Inventors: Mikio Iwamura, Minami Ishii
  • Patent number: 9706474
    Abstract: When a network is requiring access barring, a mobile device determines whether a reference value broadcasted to the mobile device indicates a value determining that an access is denied regardless of a numerical value generated by the mobile device, or indicates a value having a possibility that an access of a certain mobile device is denied while an access of another mobile device is allowed. In the latter case, the mobile device determines appropriateness of an access by performing predetermined processing using the reference value as a value to be checked for a relationship with a numerical value generated by the mobile device when the mobile device does not have a special type access class, and uses a value enabling allowance of an access without performing the predetermined processing as a value for determining appropriateness of an access when the mobile device has the special type access class.
    Type: Grant
    Filed: May 21, 2013
    Date of Patent: July 11, 2017
    Assignee: NTT DOCOMO, INC.
    Inventors: Kenichiro Aoyagi, Mikio Iwamura, Minami Ishii, Mutsumi Ishimoto
  • Publication number: 20170078057
    Abstract: Transmission/reception timing of a data signal and a control signal through a Uu interface and transmission/reception timing of the data signal through a Ud interface are properly adjusted. A mobile communication method according to the present invention includes: a step A in which a radio base station eNB notifies a mobile station UE#1 and a mobile station UE#2 that an opportunity to transmit and receive the data signal through the Ud interface is allocated through a PDCCH in which an X-RNTI is used; and a step B in which the radio base station eNB transmit “direction information”, for notifying of a direction in which the data signal should be transmitted in the opportunity, to the mobile station UE#1 and the mobile station UE#2.
    Type: Application
    Filed: November 29, 2016
    Publication date: March 16, 2017
    Applicant: NTT DOCOMO, INC.
    Inventors: Mikio Iwamura, Anil Umesh
  • Publication number: 20170048918
    Abstract: A method for waking up one or more sleeping small cell base stations in a wireless communication system for serving a user equipment is described. The wireless communication system includes a plurality of small cell base stations and one or more macro base stations. A wake up signal configuration is received at a user equipment, and a wake up signal configured in accordance with the received wake up signal configuration is transmitted by the user equipment.
    Type: Application
    Filed: October 28, 2016
    Publication date: February 16, 2017
    Inventors: Mikio IWAMURA, Emmanuel TERNON, Patrick AGYAPONG
  • Patent number: 9544106
    Abstract: Transmission/reception timing of a data signal and a control signal through a Uu interface and transmission/reception timing of the data signal through a Ud interface are properly adjusted. A mobile communication method according to the present invention includes: a step A in which a radio base station eNB notifies a mobile station UE#1 and a mobile station UE#2 that an opportunity to transmit and receive the data signal through the Ud interface is allocated through a PDCCH in which an X-RNTI is used; and a step B in which the radio base station eNB transmit “direction information”, for notifying of a direction in which the data signal should be transmitted in the opportunity, to the mobile station UE#1 and the mobile station UE#2.
    Type: Grant
    Filed: May 10, 2012
    Date of Patent: January 10, 2017
    Assignee: NTT DOCOMO, INC.
    Inventors: Mikio Iwamura, Anil Umesh
  • Publication number: 20160380805
    Abstract: A reconnection procedure is successfully performed even when a connection destination radio base station does not manage “UE Context” for a mobile station UE. A mobile communication method according to the present invention includes a step B in which the mobile station UE transmits CGI of cell #1 to a radio base station eNB#2 in the reconnection procedure, and a step C in which the radio base station eNB#2 acquires “UE Context” for the mobile station UE from a radio base station eNB#1 managing cell #1 designated based on the CGI when not managing “UE Context” for the mobile station UE in the reconnection procedure.
    Type: Application
    Filed: September 7, 2016
    Publication date: December 29, 2016
    Applicant: NTT DOCOMO, INC.
    Inventors: Hideaki Takahashi, Mikio Iwamura
  • Publication number: 20160366577
    Abstract: A method is presented for transmitting a discovery signal by a communication device to enable its discovery by other communication devices, said method comprising the steps of: encoding a resource hopping pattern in said discovery signal, said hopping pattern defining a sequence of resources, and repeatedly transmitting said discovery signal such for each of the repeated transmissions the resource which is used for the transmission, is chosen in accordance with the sequence of resources defined by the resource hopping pattern, respectively. Furthermore, a method for receiving a discovery signal transmitted by a neighbour communication device is presented, wherein a resource hopping pattern of said neighbour communication device in said received discovery signal is decoded.
    Type: Application
    Filed: February 27, 2015
    Publication date: December 15, 2016
    Inventors: Liang HU, Katsutoshi KUSUME, Mikio IWAMURA
  • Patent number: 9520969
    Abstract: The present invention is a mobile communication system having a mobile station UE, in which CA is performed, configured to transmit an uplink data signal to a radio base station eNB, by using a plurality of “Component Carriers” having different carrier frequencies, and the mobile communication system includes TA timer management units 13 and 23 configured to manage the TA timer corresponding to the plurality of “Component Carriers”; and state management units 14 and 24 configured to manage the state of the plurality of “Component Carriers”, and the state management units 14 and 24 are configured to set the state of a “Component Carrier”, whose TA timer has expired, to an asynchronous state.
    Type: Grant
    Filed: January 7, 2011
    Date of Patent: December 13, 2016
    Assignee: NTT DOCOMO, INC.
    Inventors: Mikio Iwamura, Anil Umesh
  • Patent number: 9521639
    Abstract: Orthogonality between signals is maintained in direct communication between a mobile station UE#1 and a mobile station UE#2. In a mobile communication system according to the present invention, a radio base station eNB is configured to transmit a data signal to the UE#1 and the UE#2 through a Uu interface at a frequency f1, the UE#1 and the UE#2 are configured to transmit the data signal to the radio base station eNB through the Uu interface at a frequency F2, the UE#1 and the UE#2 are configured to transmit and receive the data signal to and from each other in a time-division manner through a Ud interface at the frequency F2, and predetermined gaps are configured to be provided before and after timing in which the UE#1 and the UE#2 transmit the data signal through the Ud interface.
    Type: Grant
    Filed: May 11, 2012
    Date of Patent: December 13, 2016
    Assignee: NTT DOCOMO, INC.
    Inventors: Mikio Iwamura, Tooru Uchino
  • Publication number: 20160345250
    Abstract: A method is described for interference control among a first small cell base station and a second small cell base station in a wireless communication system having a plurality of small cell base stations controlled by a macro base station. The method has, in response to a request from the macro base station to the first small cell base station, performing, by the first small cell base station, a beacon transmission on one or more resources, in response to a request from the macro base station to the second small cell base station, performing, by the second small cell base station, a channel quality measurement on the one or more resources, and reporting the measured channel quality from the second small cell base station to the macro base station.
    Type: Application
    Filed: May 27, 2016
    Publication date: November 24, 2016
    Inventors: Patrick AGYAPONG, Emmanuel TERNON, Liang HU, Katsutoshi KUSUME, Mikio IWAMURA
  • Publication number: 20160345194
    Abstract: A method is described for controlling a small cell base station and a user equipment to be served by the small base station in a wireless communication system having a plurality of small cell base stations controlled by a macro base station. The method has, in response to a request from the macro base station to the small cell base station, performing, by the small cell base station, a beacon transmission on one or more resources, in response to a request from the macro base station to the user equipment, performing, by the user equipment, a channel quality measurement on the one or more resources, and reporting the measured channel quality from the user equipment to the macro base station.
    Type: Application
    Filed: May 27, 2016
    Publication date: November 24, 2016
    Inventors: Patrick AGYAPONG, Emmanuel TERNON, Liang HU, Katsutoshi KUSUME, Mikio IWAMURA
  • Publication number: 20160345224
    Abstract: A method is described for controlling a user equipment to be served by a small cell base station in a wireless communication system including a plurality of small cell base stations controlled by a macro base station. The method includes signaling, by the small cell base station, the small cell base station capabilities to the macro base station; signaling, by the user equipment, the user equipment capabilities to the macro base station; and signaling, by the macro base station, a small cell base station configuration to the user equipment.
    Type: Application
    Filed: May 27, 2016
    Publication date: November 24, 2016
    Inventors: Patrick AGYAPONG, Emmanuel TERNON, Liang HU, Katsutoshi KUSUME, Mikio IWAMURA
  • Patent number: 9491643
    Abstract: A user apparatus including at least operation modes of a connection mode and an idle mode, includes: a measurement unit that measures radio quality in the idle mode according to measurement target information (Config#m, Config#n) indicating that the user apparatus is set beforehand to report a measurement value of radio quality to a management node; a storage unit that stores the measurement target information and the measurement value of radio quality measured by the measurement unit; and a transmission unit that transmits, in the connection mode, an indicator indicating that there is the measurement value of radio quality to the management node, and transmits a report signal including the measurement value of radio quality to the management node according to a request from the management node, wherein, when the user apparatus obtains new measurement target information (Config#n), the storage unit stores the new measurement target information according to a predetermined updating rule (reconfiguration model)
    Type: Grant
    Filed: April 27, 2011
    Date of Patent: November 8, 2016
    Assignee: NTT DOCOMO, INC.
    Inventors: Wuri Andarmawanti Hapsari, Anil Umesh, Mikio Iwamura, Hideaki Takahashi
  • Patent number: 9479930
    Abstract: The present invention relates to a mobile communication method of sending and receiving the signaling of an S1AP/X2AP layer on DRB established between a radio base station DeNB and a relay node RN, the method comprising a step of generating a key KS1X2_int for performing integrity protection in the above DRB, in an SMC (security mode command) process performed in an attach process of the relay node RN.
    Type: Grant
    Filed: August 12, 2011
    Date of Patent: October 25, 2016
    Assignee: NTT DOCOMO, INC.
    Inventors: Hideaki Takahashi, Wuri Andarmawanti Hapsari, Anil Umesh, Mikio Iwamura