Patents by Inventor Yoshikazu Kakura

Yoshikazu Kakura 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).

  • Resource allocation method, identification method, radio communication system, base station, mobile station, and program
    Patent number: 9350485
    Abstract: To solve a problem that although the increase of the number of frequency blocks by allocating discontinuous subcarriers (RBs) as in OFDM enables an increase in multi-diversity effect and an improvement in throughput, the number of RB allocation patterns increases with the increase of the number of frequency blocks, resulting in an increase in the amount of information relating to the allocated RBs, the resource block allocation unit is determined when resource blocks discontinuous on the frequency axis are allocated to a terminal, and the number of bits of scheduling information indicating the allocated resource blocks by using Tree Based is set to the number of bits corresponding to the determined allocation unit.
    Type: Grant
    Filed: June 19, 2009
    Date of Patent: May 24, 2016
    Assignee: NEC CORPORATION
    Inventors: Kenji Koyanagi, Takamichi Inoue, Le Liu, Yoshikazu Kakura
  • Single carrier transmission system, communication device, and single carrier transmission method using for them
    Patent number: 9288025
    Abstract: A memory 21 of a pilot processing circuit 2 holds in advance a pilot sequence converted into a frequency region signal obtained by subjecting a pilot signal symbol transmitted in one block to Ntx_p-point DFT. The pilot sequence held in the memory 21 is subjected to a series of processes including a roll-off filtering by a roll-off filter circuit 22, subcarrier mapping process by subcarrier mapping circuit 23, an Ndft_p-point IDFT operation by an IDFT circuit 24, and a cyclic prefix adding process by a cyclic prefix adding circuit 25.
    Type: Grant
    Filed: August 30, 2013
    Date of Patent: March 15, 2016
    Assignee: LENOVO INNOVATIONS LIMITED (HONG KONG)
    Inventors: Kengo Oketani, Yoshikazu Kakura, Toshifumi Sato, Shousei Yoshida
  • Wireless communication system, wireless communication setting method, base station, mobile station, and program
    Patent number: 9277545
    Abstract: A base station includes a transmitter configured to transmit a downlink controlling formation to a user equipment, the downlink control information being generated based on an uplink allocation information indicating a first frequency block corresponding to a first plurality of subcarriers which are contiguous in frequency and a second frequency block corresponding to a second plurality of subcarriers which are contiguous in frequency, wherein at least a subcarrier, which is not indicated by the uplink allocation information, is located between the first frequency block and the second frequency block; and a receiver configured to receive a reference signal including a reference signal sequence having a sequence length corresponding to a first bandwidth which is a summation of a second bandwidth of the first frequency block and a third bandwidth of the second frequency block.
    Type: Grant
    Filed: March 26, 2015
    Date of Patent: March 1, 2016
    Assignee: NEC Corporation
    Inventors: Takamichi Inoue, Kenji Koyanagi, Le Liu, Yoshikazu Kakura
  • METHOD AND SYSTEM FOR NETWORK-ASSISTED INTERFERENCE SUPPRESSION/CANCELATION
    Publication number: 20150382371
    Abstract: A system which can achieve effective interference suppression/cancelation in downlink coordinated multi-point (CpMP) transmission is provided. The system has a network including multiple points which are capable of communicating with a user equipment, wherein the network sends information related to an interfering point to the user equipment for interference suppression or cancelation at the user equipment, wherein the interfering point is a candidate for a coordinated multi-point measurement set of the user equipment but not selected for any coordinated multi-point scheme.
    Type: Application
    Filed: February 7, 2013
    Publication date: December 31, 2015
    Applicant: NEC CORPORATION
    Inventors: Le LIU, Naoto ISHII, Yoshikazu KAKURA
  • TERMINAL APPARATUS, BASE STATION APPARATUS, AND METHOD FOR SHARING CODEBOOK IN COMMUNICATION SYSTEM
    Publication number: 20150372729
    Abstract: A communication system, a terminal apparatus, a base station apparatus, and a method for sharing a codebook are provided that make it possible to improve system capacity by using precoding according to a cell environment. In a communication system in which beam directivity control is performed by precoding using a codebook that is common between a base station (10) and a terminal (20), the base station (10) notifies the terminal (20) information for codebook determination k including cell (11)-specific information on the base station, and the base station (10) and the terminal (20) generate the common codebook based on the information for codebook determination.
    Type: Application
    Filed: January 31, 2013
    Publication date: December 24, 2015
    Applicant: NEC CORPORATION
    Inventors: Shinichi TAJIMA, Naoto ISHII, Yoshikazu KAKURA
  • RADIO COMMUNICATION SYSTEM AND COMMUNICATION METHOD
    Publication number: 20150304018
    Abstract: A communication system includes a plurality of DeNBs (base stations) and a plurality of RNs (relay nodes), wherein each RN has a radio connection with a DeNB. Each DeNB acquires time resource configuration applied between another base station and a relay node connected with said another base station.
    Type: Application
    Filed: February 21, 2013
    Publication date: October 22, 2015
    Applicant: NEC CORPORATION
    Inventors: Boonsarn PITAKDUMRONGKIJA, Yoshikazu KAKURA, Naoto ISHII
  • Radio communication system and control method of radio resource allocation
    Patent number: 9107228
    Abstract: A communication system includes a plurality of nodes including a base station; at least one terminal; and at least one relay node through which each terminal can be connected to the base station. An entity in a network higher in layer than each relay node configures the relay node to set a target value for a predetermined parameter reflecting a radio link status of the relay node. The relay node monitors the predetermined parameter to notify an upper-layer node of difference information corresponding to a difference between the target value and a monitored parameter value. The upper-layer node controls a link parameter of a radio link connecting the upper-layer node and the relay node depending on the difference information, resulting in efficient radio resource allocation in a relay network with small signaling overhead.
    Type: Grant
    Filed: June 17, 2010
    Date of Patent: August 11, 2015
    Assignee: NEC CORPORATION
    Inventors: Boonsarn Pitakdumrongkija, Hiroaki Aminaka, Yoshikazu Kakura
  • Synchronization system and synchronizing method for plurality of base stations and mobile station in a reverse link wireless transmission
    Patent number: 9100876
    Abstract: There is provided a wireless communication system which can synchronize a mobile station with a destination base station in response to the mobile station determining to switch base stations. Each base station generates synchronization information to synchronize the mobile station with the base station from a reverse pilot signal received from the mobile station, generates reverse propagation quality information from the reverse pilot signal, and generates and transmits a control signal including the synchronization information and the reverse propagation quality information. A mobile station generates and transmits a reverse pilot signal, receives a signal including the control signal from each of the base stations.
    Type: Grant
    Filed: June 10, 2014
    Date of Patent: August 4, 2015
    Assignee: NEC CORPORATION
    Inventors: Kenji Koyanagi, Yoshikazu Kakura, Jinsock Lee, Nahoko Kuroda
  • WIRELESS COMMUNICATION SYSTEM, WIRELESS COMMUNICATION SETTING METHOD, BASE STATION, MOBILE STATION, AND PROGRAM
    Publication number: 20150201409
    Abstract: A base station includes a transmitter configured to transmit a downlink controlling formation to a user equipment, the downlink control information being generated based on an uplink allocation information indicating a first frequency block corresponding to a first plurality of subcarriers which are contiguous in frequency and a second frequency block corresponding to a second plurality of subcarriers which are contiguous in frequency, wherein at least a subcarrier, which is not indicated by the uplink allocation information, is located between the first frequency block and the second frequency block; and a receiver configured to receive a reference signal including a reference signal sequence having a sequence length corresponding to a first bandwidth which is a summation of a second bandwidth of the first frequency block and a third bandwidth of the second frequency block.
    Type: Application
    Filed: March 26, 2015
    Publication date: July 16, 2015
    Inventors: Takamichi INOUE, Kenji KOYANAGI, Le LlU, Yoshikazu KAKURA
  • METHOD FOR MULTIPLEXING CONTROL SIGNALS AND REFERENCE SIGNALS IN MOBILE COMMUNICATIONS SYSTEM
    Publication number: 20150189632
    Abstract: A reference signal multiplexing method for multiple mobile stations includes: grouping together control signals for the multiple mobile stations; and multiplexing reference signals corresponding to the control signals by CDM over the same bandwidth as that of grouped control signals.
    Type: Application
    Filed: March 12, 2015
    Publication date: July 2, 2015
    Applicant: NEC CORPORATION
    Inventors: Takamichi INOUE, Yoshikazu KAKURA
  • Wireless communication system, wireless communication setting method, base station, mobile station, and program
    Patent number: 9031034
    Abstract: A wireless communication system including a base station and a mobile terminal, includes a setting unit to set a number of sets of at least one or more resource blocks for the mobile terminal, the at least one or more resource blocks of each set being consecutive in frequency. An allocation unit allocates the resource blocks for a transmission channel so that the resource blocks are not contiguous in frequency. A controller generates a reference signal sequence corresponding to a bandwidth of the allocated resource blocks, and maps the reference signal sequence to subcarriers according to an allocation of the resource blocks.
    Type: Grant
    Filed: July 17, 2012
    Date of Patent: May 12, 2015
    Assignee: NEC Corporation
    Inventors: Takamichi Inoue, Kenji Koyanagi, Le Liu, Yoshikazu Kakura
  • PILOT SIGNAL TRANSMISSION METHOD AND RADIO COMMUNICATION APPARATUS
    Publication number: 20150117390
    Abstract: In a radio communication system, transmission of CAZAC sequences as the pilot signal sequences by using code division multiplexing as at least one of user multiplexing schemes, is done by dividing a system band as a frequency band usable in the system into frequency blocks B1 and B2 having bandwidths W1 and W2, generating the pilot signals of the frequency blocks B1 and B2 with a single carrier, using the pilot signal sequences having sequence lengths L1 and L2 corresponding to frequency blocks B1 and B2 respectively; and, transmitting the generated pilot signals as the pilot signals corresponding individual users, with multicarriers using an arbitrary number of frequency blocks among the plural frequency blocks
    Type: Application
    Filed: January 9, 2015
    Publication date: April 30, 2015
    Applicant: NEC CORPORATION
    Inventors: Takamichi INOUE, Yoshikazu KAKURA
  • Communication system, communication method, base station, user equipment, and therein program
    Patent number: 9014711
    Abstract: The object of the present invention is to provide a technology of deciding CoMP point dynamically by considering the spectrum efficiency after channel-dependent scheduling with different possible combinations of CoMP points. According to the present invention, A wireless communication system, characterized in deciding number of CoMP (coordinated multipoint transmission and reception) point to a user equipment by using information related to scheduling.
    Type: Grant
    Filed: September 15, 2009
    Date of Patent: April 21, 2015
    Assignee: NEC Corporation
    Inventors: Le Liu, Yoshikazu Kakura
  • Method for multiplexing control signals and reference signals in mobile communications system
    Patent number: 9008110
    Abstract: A reference signal multiplexing method for multiple mobile stations includes: grouping together control signals for the multiple mobile stations; and multiplexing reference signals corresponding to the control signals by CDM over the same bandwidth as that of grouped control signals.
    Type: Grant
    Filed: July 6, 2012
    Date of Patent: April 14, 2015
    Assignee: NEC Corporation
    Inventors: Takamichi Inoue, Yoshikazu Kakura
  • RADIO COMMUNICATION SYSTEM AND COMMUNICATION METHOD
    Publication number: 20150063304
    Abstract: A base station for supporting a plurality of radio access schemes is provided. The base station includes a radio transceiver, a storage section and a response sending section. The storage section stores at least one radio access scheme supported by the base station. The at least one radio access scheme includes a predetermined radio access scheme which is common with another base station. The response sending section sends a response to an initial connection received from a mobile station back to the mobile station. The initial connection is received in the predetermined radio access scheme. The response includes information indicating one of said at least one radio access scheme which is used to communicate with the mobile station.
    Type: Application
    Filed: November 6, 2014
    Publication date: March 5, 2015
    Applicant: NEC Corporation
    Inventors: Kenji KOYANAGI, Hisashi FUTAKI, Yoshikazu KAKURA
  • Pilot signal transmission method and radio communication apparatus
    Patent number: 8964717
    Abstract: In a radio communication system, transmission of CAZAC sequences as the pilot signal sequences by using code division multiplexing as at least one of user multiplexing schemes, is done by dividing a system band as a frequency band usable in the system into frequency blocks B1 and B2 having bandwidths W1 and W2, generating the pilot signals of the frequency blocks B1 and B2 with a single carrier, using the pilot signal sequences having sequence lengths L1 and L2 corresponding to frequency blocks B1 and B2 respectively; and, transmitting the generated pilot signals as the pilot signals corresponding individual users, with multicarriers using an arbitrary number of frequency blocks among the plural frequency blocks.
    Type: Grant
    Filed: January 18, 2012
    Date of Patent: February 24, 2015
    Assignee: NEC Corporation
    Inventors: Takamichi Inoue, Yoshikazu Kakura
  • RADIO COMMUNICATION SYSTEM AND METHOD
    Publication number: 20150049621
    Abstract: A radio communication system includes a network and a user terminal, wherein the network includes a plurality of radio stations and a controller which controls the plurality of radio stations, wherein at least two of the plurality of radio stations communicate with the user terminal, wherein the controller notifies the user terminal of information about resource for interference measurement, wherein the user terminal calculates and reports channel quality information based on the information.
    Type: Application
    Filed: January 30, 2012
    Publication date: February 19, 2015
    Inventors: Le Liu, Takamichi Inoue, Naoto Ishii, Yoshikazu Kakura
  • RADIO TERMINAL, RADIO STATION, RADIO COMMUNICATION SYSTEM, AND METHODS IMPLEMENTED THEREIN
    Publication number: 20150050939
    Abstract: In one embodiment, a radio terminal (2) is used in a radio communication system (100) and communicates with a radio station (1). The radio terminal (2) includes a measurement unit (20). The measurement unit (20) operates to perform, using a terminal measurement procedure for executing a first terminal measurement corresponding to radio access technology applied to the radio communication system (100), a second terminal measurement of a shared frequency shared by a plurality of radio systems including the radio communication system (100). This embodiment therefore contributes to simplification of a measurement function which should be supported by the radio terminal when the radio communication system uses a shared frequency (e.g., TVWS) shared by the plurality of radio systems.
    Type: Application
    Filed: January 11, 2013
    Publication date: February 19, 2015
    Applicant: NEC Corporation
    Inventors: Hisashi Futaki, Hiroaki Aminaka, Hiroto Sugahara, Yoshikazu Kakura, Kazushi Muraoka
  • RADIO COMMUNICATION SYSTEM AND COMMUNICATION CONTROL METHOD
    Publication number: 20150043457
    Abstract: A radio communication system includes: a plurality of cells having different scrambling sequences, respectively, wherein at least two cells communicate with at lease two user terminals connected to different serving cells; and a controller which controls the plurality of cells and provides a single scrambling sequence to said at least two cells and said at least two user terminals for control signal transmission and reception.
    Type: Application
    Filed: January 30, 2012
    Publication date: February 12, 2015
    Inventors: Le Liu, Yoshikazu Kakura, Naoto Ishii, Takamichi Inoue
  • Wireless communication system, wireless communication setting method, base station, mobile station, and program
    Patent number: 8953551
    Abstract: A wireless communication system includes a setting unit for setting a number of resource block groups, each of the resource block groups including consecutive resource blocks on a frequency axis, and an allocating unit for allocating the resource blocks for an uplink channel such that the allocated resource blocks are not contiguous.
    Type: Grant
    Filed: March 18, 2009
    Date of Patent: February 10, 2015
    Assignee: NEC Corporation
    Inventors: Takamichi Inoue, Kenji Koyanagi, Le Liu, Yoshikazu Kakura