Patents by Inventor Koki Uwano

Koki Uwano 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: 20110064061
    Abstract: Conventionally, different HARQ processes 801 and 802 (subframes T1 and T2) transmit data packets B and D, respectively. One data packet corresponds to one process and is retransmitted as necessary one by one on a process basis, degrading the usage efficiency of frequency and time resources. To solve this problem, downlink data packets B and D, when needed to be retransmitted, are spatially multiplexed in the different HARQ processes 801 and 802. The data packets are simultaneously retransmitted to the same terminal as process 805 (subframe T3).
    Type: Application
    Filed: August 5, 2010
    Publication date: March 17, 2011
    Applicant: HITACHI, LTD.
    Inventors: Keisuke TAKEUCHI, Rintaro KATAYAMA, Tomonori YAMAMOTO, Koki UWANO
  • Publication number: 20110013714
    Abstract: A signal frequency of an interface signal between a baseband unit and a remote radio unit is decreased by downsampling, and the strain of the signal caused by downsampling is compensated for each subcarrier before an IFFT during transmission, and after FFT during reception.
    Type: Application
    Filed: July 14, 2010
    Publication date: January 20, 2011
    Inventors: Satoshi TAMAKI, Takashi Yano, Koki Uwano
  • Publication number: 20100238876
    Abstract: A method for radio resource control is carried out in a radio communications system including multiple base stations. In this method, a radio resource that can be used by the base stations is divided into multiple first radio resources on the frequency axis. Then one or more of the first radio resources are allocated to a second radio resource for initially transmitting a packet and the other first radio resources are allocated to a third radio resource for retransmitting the packet.
    Type: Application
    Filed: February 18, 2010
    Publication date: September 23, 2010
    Applicant: HITACHI, LTD.
    Inventors: Tomonori YAMAMOTO, Rintaro KATAYAMA, Keisuke TAKEUCHI, Koki UWANO
  • Publication number: 20100234035
    Abstract: A radio communications system includes at least one terminal communication unit having one antenna that conducts a radio communication with a plurality of terminals; and at least one baseband modem that generates and decrypts a data signal, a cell being configured by at least one of the antenna, wherein the baseband modem divides a radio frequency band used for the radio communication into two or more subbands, generates and decrypts the data signal specific to each of the divided subbands, and allocates the data signal specific to the subband to the terminal communication unit, and wherein the terminal communication unit receives the data signal specific to the subband generated by the baseband modem, and forms the cell of each the subband by the data signal specific to the received subband.
    Type: Application
    Filed: February 23, 2010
    Publication date: September 16, 2010
    Applicant: HITACHI, LTD.
    Inventors: Kenzaburo Fujishima, May Takada, Katsuhiko Tsunehara, Satoshi Tamaki, Shinya Sasaki, Go Ono, Koki Uwano
  • Publication number: 20100216450
    Abstract: A radio communications system includes, in base stations, or nodes nearer to a core network than the base stations, a terminal distribution checking unit, a unit of determining whether to execute intercell interference reduction based on the result of the checking, a coordination unit which executes intercell interference reduction between base stations in corporation with each other.
    Type: Application
    Filed: February 22, 2010
    Publication date: August 26, 2010
    Applicant: HITACHI, LTD.
    Inventors: Kenzaburo FUJISHIMA, Koki UWANO, May TAKADA
  • Publication number: 20100208720
    Abstract: A wireless communication system includes an asynchronized base station apparatus to perform an operation that is equivalent to the synchronization with a synchronized base station apparatus having received a sync pulse. The system includes a synchronized base station that uses a received sync pulse to synchronize itself with a base station which is a different cell, an asynchronized base station located in the cell of the synchronized base station, and a terminal. The asynchronized base station includes a unit that determines a reception timing difference, at the terminal, between a transport signal transmitted by the synchronized base station and a transport signal transmitted by the asynchronized base station, and a unit that controls the transmission timing of the asynchronized base station such that the reception timing difference becomes equal to or less than a predetermined value.
    Type: Application
    Filed: October 9, 2008
    Publication date: August 19, 2010
    Applicant: HITACHI, LTD.
    Inventors: Kenzaburo Fujishima, Koki Uwano
  • Publication number: 20100182972
    Abstract: In a conventional OFDMA/SCFDMA communication scheme, frequency resource assignment information is exchanged between BSs via a wired interface and used for control of inter-cell interference or the like. When a BS performs assignments of frequency resources, taking the status of a neighbor BS signaled via the wired interface into account, it might be impossible to follow a change in the status of the assignments of frequency resources at the neighbor BS due to a delay occurring in the wired interface. BS selects and assigns distributed frequency resources or continuous frequency resources, depending on the position of an MS in the cell and the transmit power of the BS.
    Type: Application
    Filed: January 19, 2010
    Publication date: July 22, 2010
    Applicant: HITACHI, LTD.
    Inventors: Rintaro KATAYAMA, Keisuke TAKEUCHI, Tomonori YAMAMOTO, Koki UWANO
  • Publication number: 20100157831
    Abstract: A base station is connected to wired and wireless networks to send a call that is received from the wired network to the wireless network at a predetermined quality of service (QoS), select one or more combinations of a set of modulation and coding scheme, and a radio resource amount that are associated with a QoS set in a newly incoming call, determine the radio resource amount that is equal to or less than a amount of the unassigned radio resources, assign, to the newly incoming call, the combination that is associated with the determined radio resource amount and the QoS set in the newly incoming call, reduce the radio resources assigned to the ongoing call without changing the QoS, and assign, to the newly incoming call, an amount of radio resources released from the ongoing call and modulation and coding scheme associated with this released radio resource amount.
    Type: Application
    Filed: December 18, 2009
    Publication date: June 24, 2010
    Applicant: HITACHI, LTD.
    Inventors: Keisuke Takeuchi, Rintaro Katayama, Tomonori Yamamoto, Koki Uwano
  • Publication number: 20100046462
    Abstract: Wireless communication arrangements including: performing scheduling of transmitting signal to each of the mobile stations so that interference of radio waves sent from each of the remote units to each of the mobile stations can be suppressed based on priority level of the mobile station and the interference area information; generating information to control the direction-variable antenna of each of the plurality of remote units, so that the corresponding remote unit forms beam according to scheduling result; and transmitting the information to control the direction-variable antenna to the plurality of remote units.
    Type: Application
    Filed: November 4, 2009
    Publication date: February 25, 2010
    Inventors: Koki UWANO, Masanori Taira, Kenzaburo Fujishima, Mikio Kuwahara
  • Publication number: 20100048220
    Abstract: Wireless communication arrangements including: first base station referring to beam scheduling information including identification information of a beam pattern to be used in each slot by the second base station, selecting, where identification information of the beam area to be used by the second base station in the slot assigned is coincident with the identification information of the first interference beam area received from the wireless terminal, the first data rate received from the wireless terminal, and selects, where the identification information of the beam area to be used by the second base station is not coincident with the identification information of the first interference beam area, the second data rate received from the wireless terminal; a step at which the first base station modulates data in accordance with one of the selected first data rate and second data rate, and transmits modulated data to the wireless terminal.
    Type: Application
    Filed: November 4, 2009
    Publication date: February 25, 2010
    Inventors: Masanori TAIRA, Kenzaburo FUJISHIMA, Koki UWANO
  • Publication number: 20100035542
    Abstract: Provided is a radio communication system including a plurality of base stations and a repeater apparatus, in which the repeater apparatus amplifies and transmits a radio signal received from at least one of the plurality of base stations, and controls a domain in which the radio signal is transmitted based on a traffic amount of each of the plurality of base stations. Accordingly, the number of installed base stations which are costly is reduced, and an operating rate of the respective base stations is gained along with the decrease in number of installed base stations.
    Type: Application
    Filed: June 15, 2009
    Publication date: February 11, 2010
    Inventors: Kenzaburo Fujishima, Koki Uwano
  • Patent number: 7639984
    Abstract: A wireless communication which suppresses radio interference between wireless base stations and improves the channel efficiency is implemented. In the wireless communication system including a central base station, a plurality of remote base stations having a direction-variable antenna, and a plurality of mobile stations to communicate with the remote base stations, the central base station performs centralized management of radio-wave beam patterns to be sent to the plurality of mobile stations which will communicate with remote base stations and performs packet scheduling of the mobile stations in such a manner that radio waves sent from the remote base stations will not cause strong interference at the mobile stations.
    Type: Grant
    Filed: February 9, 2006
    Date of Patent: December 29, 2009
    Assignee: Hitachi Communication Technologies, Ltd.
    Inventors: Koki Uwano, Masanori Taira, Kenzaburo Fujishima, Mikio Kuwahara
  • Publication number: 20090305741
    Abstract: Provided is a wireless base station comprising: a power control unit, a reference information acquisition unit and a reference information storing unit, wherein the wireless base station comprises a first control signal receiving unit for receiving a first uplink control signal used by a mobile station connected to the wireless base station and for requesting the power control unit to control the transmission, and a second control signal receiving unit for receiving a second uplink control signal used by a mobile station connected to the neighbor base station and for requesting the power control unit to control the transmission power, and wherein the power control unit controls the transmission power of the downlink signal based on the request to control the transmission power from the first control signal receiving unit and the request to control the transmission power from the second control signal receiving unit.
    Type: Application
    Filed: June 9, 2009
    Publication date: December 10, 2009
    Inventors: Keisuke TAKEUCHI, Kenzaburo FUJISHIMA, Rintaro KATAYAMA, Koki UWANO
  • Patent number: 7627298
    Abstract: A terminal 211 measures pilot signals transmitted in directional (beam) patterns from an adjacent cell and an own cell, and estimates reception qualities with the presence (high)/absence (low) of the interference from the adjacent cell. The terminal 211 requests data rate request values (DRC1, DRC2) corresponding to the reception qualities with the presence/absence of the interference to the base station 201. The base station 201 shares beam direction schedule with an adjacent cell base station, and confirms the presence/absence of interference to the terminal 211 for each slot. In accordance with the presence/absence of the interference, the base station 201 selects a suitable one of the two values of the data rates requested from the terminal 211, and modulates the data and transmits it.
    Type: Grant
    Filed: February 21, 2007
    Date of Patent: December 1, 2009
    Assignee: Hitachi Communication Technologies, Ltd.
    Inventors: Masanori Taira, Kenzaburo Fujishima, Koki Uwano
  • Publication number: 20090245088
    Abstract: When a receiving apparatus which employs a OFDM-based cellular wireless communication scheme detects as an excessive signal for each frame, the signal having signal intensity exceeding a reference value after a Fourier transform, a gain variable according to an excessive quantity relative to the reference value is used for each frame to control signal intensity such that the amplitude thereof is at most the reference value.
    Type: Application
    Filed: February 10, 2009
    Publication date: October 1, 2009
    Inventors: Keisuke TAKEUCHI, Kenzaburo FUJISHIMA, Rintaro KATAYAMA, Koki UWANO
  • Publication number: 20090210766
    Abstract: A non-terminated packet is transmitted, by utilizing a spatial layer responded with an ACK, which is assumed as a released layer. Alternatively, a non-terminated packet is transmitted by using a released layer and an original spatial layer in combination. Alternatively, a new packet is transmitted in a released layer by utilizating time till termination of transmission of a non-terminated packet. A wireless communication system effectively utilizing a released layer, a terminal and a base station.
    Type: Application
    Filed: February 18, 2009
    Publication date: August 20, 2009
    Inventors: Rintaro Katayama, Toshiyuki Saito, Mikio Kuwahara, Koki Uwano
  • Publication number: 20070243878
    Abstract: A terminal 211 measures pilot signals transmitted in directional (beam) patterns from an adjacent cell and an own cell, and estimates reception qualities with the presence (high)/absence (low) of the interference from the adjacent cell. The terminal 211 requests data rate request values (DRC1, DRC2) corresponding to the reception qualities with the presence/absence of the interference to the base station 201. The base station 201 shares beam direction schedule with an adjacent cell base station, and confirms the presence/absence of interference to the terminal 211 for each slot. In accordance with the presence/absence of the interference, the base station 201 selects a suitable one of the two values of the data rates requested from the terminal 211, and modulates the data and transmits it.
    Type: Application
    Filed: February 21, 2007
    Publication date: October 18, 2007
    Inventors: Masanori Taira, Kenzaburo Fujishima, Koki Uwano
  • Publication number: 20060217158
    Abstract: A wireless communication which suppresses radio interference between wireless base stations and improves the channel efficiency is implemented. In the wireless communication system including a central base station, a plurality of remote base stations having a direction-variable antenna, and a plurality of mobile stations to communicate with the remote base stations, the central base station performs centralized management of radio-wave beam patterns to be sent to the plurality of mobile stations which will communicate with remote base stations and performs packet scheduling of the mobile stations in such a manner that radio waves sent from the remote base stations will not cause strong interference at the mobile stations.
    Type: Application
    Filed: February 9, 2006
    Publication date: September 28, 2006
    Inventors: Koki Uwano, Masanori Taira, Kenzaburo Fujishima, Mikio Kuwahara