Patents by Inventor Hirohito Suda

Hirohito Suda 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: 9544159
    Abstract: A base station receives channel state information corresponding to each of spare coordinated groups from each of user devices. A first group includes a plurality of coordinated groups arranged in advance. The spare coordinated groups corresponding to each user device are such as selected from the first group and include at least a service sector of best channel quality obtained measurement by the user device. The base station specifies a user device group corresponding to each of coordinated groups contained in each of coordinated group patterns. The user device group corresponding to the coordinated group is formed of user devices having the coordinated group in their spare coordinated groups. The base station uses channel state information reported from the user devices of the user device group corresponding to the coordinated group as a basis to perform user scheduling on the coordinated group.
    Type: Grant
    Filed: March 22, 2012
    Date of Patent: January 10, 2017
    Assignee: NTT DOCOMO, INC.
    Inventors: Satoshi Nagata, Xiang Yun, Lan Chen, Xiaoming She, Juejia Zhou, Hirohito Suda
  • Patent number: 9401830
    Abstract: In order to recognize a relatively accurate channel state of each UE, a channel of the UE is reconfigured based on channel phase information and channel quality information reported from the UE to obtain a channel matrix of the UE. Besides, a channel of the UE is reconfigured based on channel phase information and channel quality information reported from the UE to obtain a channel matrix of the UE, a precoding matrix of the UE is determined based on the channel matrix of the UE, and precoding is performed on data to transmit to the UE, using the precoding matrix.
    Type: Grant
    Filed: May 10, 2012
    Date of Patent: July 26, 2016
    Assignee: NTT DOCOMO, INC.
    Inventors: Satoshi Nagata, Jianchi Zhu, Xiaoming She, Xiang Yun, Yu Jiang, Lan Chen, Hirohito Suda
  • Patent number: 9307423
    Abstract: Provided are a method for coordinating inter-cell interference in a heterogeneous network (HetNet) and the heterogeneous network. The method includes: forming M normal base stations and low-power nodes within coverage of the respective normal base stations in the heterogeneous network into a coordinated group; combining mute/non-mute states of bandwidths of the M normal base stations to obtain a plurality of states of the coordinated group; a user of each of the normal base stations feeding at least one first CQI back to the normal base station; a user of each of the low-power nodes feeding one or more second CQIs back to the low-power node; using the first CQI and the second CQIs as a basis to make capacity estimation of the coordinated group; and setting the mute/non-mute states of the bandwidths of the M normal base stations in accordance with a state of the coordinated group corresponding to an optimal system capacity so as to perform data transmission.
    Type: Grant
    Filed: July 9, 2012
    Date of Patent: April 5, 2016
    Assignee: NTT DOCOMO, INC.
    Inventors: Satoshi Nagata, Jing Wang, Yu Jiang, Xiaoming She, Lan Chen, Hirohito Suda
  • Patent number: 9241299
    Abstract: The present invention discloses a method and a device for discovering a UE, a first UE and a base station. The method for discovering a UE comprises the steps of: monitoring, by a first UE, an uplink signal in a mobile communication system; extracting, by the first UE, first information for identifying a UE that is to be discovered and that transmits the uplink signal from the monitored uplink signal; transmitting, by the first UE, a monitoring report message carrying the first information to a base station, acquiring, by the first UE, the device ID of the UE to be discovered in accordance with the monitoring report response message and completing the discovery process of the UE. According to the present invention, it is able to discover the UE without changing a channel system of an existing system and occupying time-frequency resources of the system.
    Type: Grant
    Filed: July 16, 2013
    Date of Patent: January 19, 2016
    Assignee: NTT DOCOMO, INC.
    Inventors: Qun Zhao, Yongsheng Zhang, Hirohito Suda
  • Publication number: 20140169275
    Abstract: Provided are a method for coordinating inter-cell interference in a heterogeneous network (HetNet) and the heterogeneous network. The method includes: forming M normal base stations and low-power nodes within coverage of the respective normal base stations in the heterogeneous network into a coordinated group; combining mute/non-mute states of bandwidths of the M normal base stations to obtain a plurality of states of the coordinated group; a user of each of the normal base stations feeding at least one first CQI back to the normal base station; a user of each of the low-power nodes feeding one or more second CQIs back to the low-power node; using the first CQI and the second CQIs as a basis to make capacity estimation of the coordinated group; and setting the mute/non-mute states of the bandwidths of the M normal base stations in accordance with a state of the coordinated group corresponding to an optimal system capacity so as to perform data transmission.
    Type: Application
    Filed: July 9, 2012
    Publication date: June 19, 2014
    Applicant: NTT DOCOMO, INC.
    Inventors: Satoshi Nagata, Jing Wang, Yu Jiang, Xiaoming She, Lan Chen, Hirohito Suda
  • Publication number: 20140064236
    Abstract: In order to recognize a relatively accurate channel state of each UE, a channel of the UE is reconfigured based on channel phase information and channel quality information reported from the UE to obtain a channel matrix of the UE. Besides, a channel of the UE is reconfigured based on channel phase information and channel quality information reported from the UE to obtain a channel matrix of the UE, a precoding matrix of the UE is determined based on the channel matrix of the UE, and precoding is performed on data to transmit to the UE, using the precoding matrix.
    Type: Application
    Filed: May 10, 2012
    Publication date: March 6, 2014
    Applicant: NTT DOCOMO, INC.
    Inventors: Satoshi Nagata, Jianchi Zhu, Xiaoming She, Xiang Yun, Yu Jiang, Lan Chen, Hirohito Suda
  • Publication number: 20140024369
    Abstract: The present invention discloses a method and a device for discovering a UE, a first UE and a base station. The method for discovering a UE comprises the steps of: monitoring, by a first UE, an uplink signal in a mobile communication system; extracting, by the first UE, first information for identifying a UE that is to be discovered and that transmits the uplink signal from the monitored uplink signal; transmitting, by the first UE, a monitoring report message carrying the first information to a base station, acquiring, by the first UE, the device ID of the UE to be discovered in accordance with the monitoring report response message and completing the discovery process of the UE. According to the present invention, it is able to discover the UE without changing a channel system of an existing system and occupying time-frequency resources of the system.
    Type: Application
    Filed: July 16, 2013
    Publication date: January 23, 2014
    Inventors: Qun Zhao, Yongsheng Zhang, Hirohito Suda
  • Publication number: 20140016533
    Abstract: A base station receives channel state information corresponding to each of spare coordinated groups from each of user devices. A first group includes a plurality of coordinated groups arranged in advance. The spare coordinated groups corresponding to each user device are such as selected from the first group and include at least a service sector of best channel quality obtained measurement by the user device. The base station specifies a user device group corresponding to each of coordinated groups contained in each of coordinated group patterns. The user device group corresponding to the coordinated group is formed of user devices having the coordinated group in their spare coordinated groups. The base station uses channel state information reported from the user devices of the user device group corresponding to the coordinated group as a basis to perform user scheduling on the coordinated group.
    Type: Application
    Filed: March 22, 2012
    Publication date: January 16, 2014
    Applicant: NTT DOCOMO, INC.
    Inventors: Satoshi Nagata, Xiang Yun, Lan Chen, Xiaoming She, Juejia Zhou, Hirohito Suda
  • Patent number: 8306133
    Abstract: A transmitter which transmits information in transmission frame to a receiver, the transmission frame including multiple transmission symbols and guard intervals obtained by replicating a fixed time period of a transmission symbol, generates a transmission frame by making phases of one transmission symbol out of two transmission symbols and a guard interval thereof continuous with phases of the other transmission symbol and a guard interval thereof, when the two continuous transmission symbols are the same.
    Type: Grant
    Filed: September 28, 2007
    Date of Patent: November 6, 2012
    Assignee: NTT DoCoMo, Inc.
    Inventors: Hirohito Suda, Hiromasa Fujii
  • Publication number: 20110274197
    Abstract: The present invention provides a method for transmitting MIMO related information. The method includes: encoding MIMO related information of a user equipment (UE) by a base station, and transmitting downlink control signaling including a result of the encoding; receiving by the UE the downlink control signaling transmitted by the base station, obtaining the result of the encoding, and obtaining the MIMO related information of the UE by decoding the result of the encoding. By adopting the method, the base station is enabled to transmit MIMO related information required by the UE to the UE with small signaling overhead.
    Type: Application
    Filed: May 3, 2011
    Publication date: November 10, 2011
    Applicant: NTT DoCoMo, Inc.
    Inventors: Jianchi Zhu, Xiaoming She, Lan Chen, Hidekazu Taoka, Hirohito Suda
  • Patent number: 8019013
    Abstract: A receiver that receives a signal from a transmitter, including: a plurality of antennas; a channel estimation unit; a channel accumulation unit; a transmission weight generator; a feedback information transmission unit; and a reception weight generator. The plurality of antennas receive a second signal from the transmitter, the second signal being transmitted by using first feedback information. The channel estimation unit estimates a communication channel state on the basis of the second signal, and then outputs second channel estimation information. The reception weight generator generates reception weight information to be multiplied by the second signal, on the basis of first channel estimation information accumulated in the channel accumulation unit and a first transmission weight.
    Type: Grant
    Filed: July 20, 2010
    Date of Patent: September 13, 2011
    Assignee: NTT DoCoMo, Inc.
    Inventors: Takefumi Yamada, Hirohito Suda, Shigeru Tomisato
  • Publication number: 20110007832
    Abstract: A receiver that receives a signal from a transmitter, including: a plurality of antennas; a channel estimation unit; a channel accumulation unit; a transmission weight generator; a feedback information transmission unit; and a reception weight generator. The plurality of antennas receive a second signal from the transmitter, the second signal being transmitted by using first feedback information. The channel estimation unit estimates a communication channel state on the basis of the second signal, and then outputs second channel estimation information. The reception weight generator generates reception weight information to be multiplied by the second signal, on the basis of first channel estimation information accumulated in the channel accumulation unit and a first transmission weight.
    Type: Application
    Filed: July 20, 2010
    Publication date: January 13, 2011
    Applicant: NTT DoCoMo, Inc
    Inventors: Takefumi YAMADA, Hirohito SUDA, Shigeru TOMISATO
  • Patent number: 7826541
    Abstract: A wireless relay system for relaying a radio signal transmitted from a first wireless station to a second wireless station via a wireless relay apparatus is disclosed. The wireless relay system includes a relay control part for receiving transmission symbols transmitted from the first wireless station and refraining from relaying a portion of the symbols, a pilot signal transmission part for transmitting a pilot signal that is inserted into a section of the portion of the transmission symbols, a coupling loop interference wave estimation part for receiving the pilot signal and estimating a coupling loop interference wave based on the pilot signal, and a coupling loop interference wave cancellation part for subtracting the estimated coupling loop interference wave from a reception signal.
    Type: Grant
    Filed: February 18, 2005
    Date of Patent: November 2, 2010
    Assignee: NTT DoCoMo, Inc.
    Inventors: Hiromasa Fujii, Hirohito Suda, Tetsu Tanaka
  • Patent number: 7813440
    Abstract: This invention provides an MIMO communication system and MIMO communication method. An MIMO receiver estimates state of each communication channel from the received signals received by #1 to #L antennas, generates feedback information according to the information of channel state, sends the feedback information to a transmitter through a feedback path, processes the feedback information in order to compensate feedback-delay of the feedback path, generate K*L proper reception weights by using the information of channel state and processed feedback information, multiplies the received #1 to #L substreams of respective #1 to #K signal streams by the proper #1 to #L reception weights, respectively, composes the #1 to #L weighted substreams to obtain respective composed #1 to #K signal streams and demodulate the composed #1 to #K signal streams, respectively, and combines the demodulated K signal streams to reproduce an original transmission signal.
    Type: Grant
    Filed: January 30, 2004
    Date of Patent: October 12, 2010
    Assignee: NTT DoCoMo, Inc.
    Inventors: Takefumi Yamada, Hirohito Suda, Shigeru Tomisato
  • Patent number: 7783311
    Abstract: A receiving station used in a wireless communication system receives information from one or more transmitting stations. The receiving station comprises a receiving unit (112) configured to receive information containing ID information of a transmitting station, and a data extracting unit (1011) configured to extract the ID information from the received information. Transmit timing sequence acquiring means (2012, 2013 and 2014) of the receiving station estimates a transmit timing sequence (Hs) of the transmitting station based on the extracted ID information. Synchronizing means (2014) of the receiving station brings the receive timing of the receiving station in synchronization with transmit timing of the transmitting station based on the transmit timing sequence.
    Type: Grant
    Filed: September 9, 2004
    Date of Patent: August 24, 2010
    Assignee: NTT DoCoMo, Inc.
    Inventors: Kosei Takiishi, Shinzo Ohkubo, Hirohito Suda
  • Publication number: 20100111207
    Abstract: A transmitter which transmits information in transmission frame to a receiver, the transmission frame including multiple transmission symbols and guard intervals obtained by replicating a fixed time period of a transmission symbol, generates a transmission frame by making phases of one transmission symbol out of two transmission symbols and a guard interval thereof continuous with phases of the other transmission symbol and a guard interval thereof, when the two continuous transmission symbols are the same.
    Type: Application
    Filed: September 28, 2007
    Publication date: May 6, 2010
    Applicant: NTT DoCoMo, Inc.
    Inventors: Hirohito Suda, Hiromasa Fujii
  • Patent number: 7652981
    Abstract: Symbols converted by a serial-to-parallel converting part (12) from serial to parallel form are subjected to inverse Fourier transform processing in an inverse Fourier transform part (13) as sub-carrier signal components of a frequency interval equal to the symbol rate, then the levels of the resulting time domain signal components are compared with a permissible peak level Cth in a peak component detecting part (22) to detect peak components, and the peak components are transformed by a Fourier transform part (23) to frequency domain components, which are subtracted by subtractors (240 to 24N?1) from the corresponding sub-carrier signal components to thereby reduce the peak power.
    Type: Grant
    Filed: December 2, 2003
    Date of Patent: January 26, 2010
    Assignee: NTT DoCoMo, Inc.
    Inventors: Shigeru Tomisato, Hirohito Suda, Takefumi Yamada
  • Patent number: 7646820
    Abstract: A transmission apparatus used in a radio communication system adopting the OFDM scheme is disclosed. The transmission apparatus includes: a dividing inverse Fourier transform part including plural transform parts, wherein the dividing inverse Fourier transform part divides a signal to be transmitted into plural signals, and each of the plural transform parts performs inverse Fourier transform on one of the plural signals; a peak control part for outputting a peak control signal based on peaks that are detected from output signals of the dividing inverse Fourier transform part; and a peak reducing process part for adjusting a weight or an arranging order of an output signal of the dividing inverse Fourier transform part according to the peak control signal to output an adjusted signal, and synthesizing the adjusted signal with other signal so as to output a synthesized signal.
    Type: Grant
    Filed: May 24, 2005
    Date of Patent: January 12, 2010
    Assignee: NTT DoCoMo, Inc.
    Inventors: Jiyun Shen, Hiromasa Fujii, Takahiro Asai, Hirohito Suda
  • Patent number: 7633924
    Abstract: An object of the present invention is to provide a communications system etc., which can reduce the influence of interference from other systems which results from a difference in symbol length, in an area where a plurality of systems using different transmission methods are mixed. The present invention relates to a communications system in which a plurality of systems share the same frequency bandwidth so as to transmit information symbols. One of the plurality of systems 1 includes an identifying unit 109 configured to identify the symbol length of an information symbol transmitted in a different system 2; and an adjusting unit 102, 107 configured to adjust the symbol length of an information symbol to be transmitted, in accordance with an identified symbol length.
    Type: Grant
    Filed: November 20, 2003
    Date of Patent: December 15, 2009
    Assignee: NTT DoCoMo, Inc.
    Inventors: Hiromasa Fujii, Shigeru Tomisato, Hirohito Suda, Tetsushi Abe, Takefumi Yamada
  • Patent number: 7619963
    Abstract: An OFDM signal frame generator includes a rate determiner configured to determine rate information to generate a signal frame to be transmitted as an OFDM signal based on a value of a received signal quality. The signal frame generator further includes a pilot and data arrangement format determiner configured to determine a pilot and data arrangement format of the signal that is to be transmitted; power amplification rate determiner configured to determine a power amplification rate for the signal frame; data symbol generator configured to generate data symbol series to be transmitted based on the rate information and based on the power amplification rate; and transmission signal frame generator configured to generate the signal frame based on the generated data symbol series, on the number of pilot symbols, and based on the pilot & data arrangement format.
    Type: Grant
    Filed: June 14, 2004
    Date of Patent: November 17, 2009
    Assignee: NTT DoCoMo, Inc.
    Inventors: Tetsushi Abe, Hirohito Suda, Shigeru Tomisato, Hiromasa Fujii, Takefumi Yamada