Patents by Inventor Hidetoshi Kayama

Hidetoshi Kayama 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: 10051490
    Abstract: A determination apparatus for determining communication availability in an Orthogonal Frequency Division Multiplexing (OFDM) scheme communication system, the determination apparatus includes a reception unit configured to receive a wireless signal including an OFDM symbol in which a pilot signal is inserted at a constant interval in a frequency axis direction, an obtaining unit configured to obtain a discrete sample signal by sampling the wireless signal, a correlation value calculation unit configured to calculate a correlation value of the discrete sample signal for a time shift amount that is defined in advance according to the constant interval, and a determination unit configured to determine the communication availability in the communication system based on at least a result of determination whether the correlation value for the time shift amount has a peak or not.
    Type: Grant
    Filed: February 20, 2013
    Date of Patent: August 14, 2018
    Assignee: NTT DOCOMO, INC.
    Inventors: Hiroki Harada, Hidetoshi Kayama
  • Patent number: 9960875
    Abstract: The present disclosure provides a base station, a communication system and a method thereof. The communication system includes three base stations adjacent to each other, and each base station serves at least one UE. The method includes: acquiring, by each base station, a channel matrix of a channel from the base station to an adjacent base station; calculating an interference alignment-based transmission precoding matrix for each base station based on the channel matrices of the channels between the base stations; and precoding, by each base station, data to be transmitted with the interference alignment-based transmission precoding matrix.
    Type: Grant
    Filed: April 9, 2015
    Date of Patent: May 1, 2018
    Assignee: NTT DOCOMO, INC.
    Inventors: Chongning Na, Xiaolin Hou, Atsushi Harada, Hidetoshi Kayama
  • Patent number: 9620864
    Abstract: A method of designing a reflectarray including a substrate having a surface perpendicular to a predetermined axis, wherein elements are disposed on the substrate. The method obtains a reflection phase of the elements as a function of a design parameter such as element spacing, when a radio wave enters the arranged elements, and stores a relationship between the reflection phase and the design parameter in a memory. Here, the design parameter is equally set for the elements. The method repeatedly determines, for each of the elements, the design parameter of a specific element in accordance with the relationship. The function of the design parameter has a range of almost 360 degrees with respect to a range of the design parameter. The reflection phase is the continuous function of the element spacing such that two resonant points occur at which the reflection phase becomes zero.
    Type: Grant
    Filed: December 3, 2012
    Date of Patent: April 11, 2017
    Assignee: NTT DOCOMO, INC.
    Inventors: Tamami Maruyama, Yasuhiro Oda, Hidetoshi Kayama, Ngoc Hao Tran, Jiyun Shen
  • Patent number: 9531079
    Abstract: A reflectarray reflects an incident wave in a desired direction. The reflectarray includes a substrate including a surface which is perpendicular to a predetermined axis; and at least first and second element groups, wherein the first and second element groups are disposed on the substrate, and include elements that reflect a radio wave. The first element group and the second element group reflect the radio wave with corresponding reflection phases which are different from each other. The radio wave enters while forming an angle other than 0 degrees with respect to the predetermined axis. The elements included in the first element group reflect the radio wave with a first reflection phase, and the elements included in the second element group reflect the radio wave with a second reflection phase, wherein the second reflection phase is different from the first reflection phase.
    Type: Grant
    Filed: December 3, 2012
    Date of Patent: December 27, 2016
    Assignee: NTT DOCOMO, INC.
    Inventors: Tamami Maruyama, Yasuhiro Oda, Hidetoshi Kayama, Ngoc Hao Tran, Jiyun Shen
  • Patent number: 9451603
    Abstract: The present application provides an information transmission method, an information transmission apparatus, and a base station. The information transmission method comprises: an allocation step of, according to a search space allocation mode, performing search space allocation in a target resource consisting of at least two resource subsets and allocating, for the first user, a first search space capable of transmitting the first user control information, the search space allocation mode being associated with the at least two resource subsets; and a first transmission step of transmitting the first user control information via the first search space so that the first user can acquire the first user control information from the first search space according to the search space allocation mode. According to the present invention, the resource utilization efficiency will be improved.
    Type: Grant
    Filed: October 17, 2013
    Date of Patent: September 20, 2016
    Assignee: NTT DoCoMo, Inc.
    Inventors: Qin Mu, Liu Liu, Lan Chen, Hidetoshi Kayama, Kazuaki Takeda
  • Patent number: 9425512
    Abstract: A reflectarray reflects an incident wave in a desired direction. The reflectarray includes a substrate including a surface which is perpendicular to a predetermined axis, and elements disposed on the substrate. A specific element among the elements reflects the incident wave with a specific reflection phase among a plurality of reflection phases. Each of the elements has an element structure including, at least, a patch and a ground plate. Element spacing of first neighboring elements is different from element spacing of second neighboring elements, and a length of a gap between patches of the first neighboring elements is equal to a length of a gap between patches of the second neighboring elements.
    Type: Grant
    Filed: December 3, 2012
    Date of Patent: August 23, 2016
    Assignee: NTT DOCOMO, INC.
    Inventors: Tamami Maruyama, Yasuhiro Oda, Hidetoshi Kayama, Jiyun Shen, Ngoc Hao Tran
  • Patent number: 9184508
    Abstract: A multi-beam reflectarray includes two or more element arrays including plural elements aligned along a predetermined direction. The multi-beam reflectarray is such that, in each of a first element group and a second element group included in at least one of the element arrays, a difference between phases of radio waves reflected by corresponding two elements is in proportion to a first product of a distance between the two elements and a value of a trigonometric function with respect to an angle of reflection by the two elements, and a distance between neighboring elements in the first element group is equal to a product of a rational number and a distance between neighboring elements in the second element group.
    Type: Grant
    Filed: August 15, 2012
    Date of Patent: November 10, 2015
    Assignee: NTT DOCOMO, INC.
    Inventors: Tamami Maruyama, Yasuhiro Oda, Jiyun Shen, Ngoc Hao Tran, Hidetoshi Kayama
  • Publication number: 20150295671
    Abstract: The present disclosure provides a base station, a communication system and a method thereof. The communication system includes three base stations adjacent to each other, and each base station serves at least one UE. The method includes: acquiring, by each base station, a channel matrix of a channel from the base station to an adjacent base station; calculating an interference alignment-based transmission precoding matrix for each base station based on the channel matrices of the channels between the base stations; and precoding, by each base station, data to be transmitted with the interference alignment-based transmission precoding matrix.
    Type: Application
    Filed: April 9, 2015
    Publication date: October 15, 2015
    Applicant: NTT DoCoMo, Inc.
    Inventors: Chongning NA, Xiaolin HOU, Atsushi HARADA, Hidetoshi KAYAMA
  • Patent number: 9042900
    Abstract: A CRS base station (21) includes a transmitting section configured to transmit a synchronization establishment signal, a receiving section configured to receive a random access signal corresponding to the synchronization establishment signal, a determining section configured to determine whether or not the random access signal received by the receiving section has been transmitted from an MCS terminal (12) and an interference reduction processing section configured to perform interference reduction processing on the MCS terminal (12) when the determining section determines that the random access signal has been transmitted from the MCS terminal (12).
    Type: Grant
    Filed: April 11, 2014
    Date of Patent: May 26, 2015
    Assignee: NTT DOCOMO, INC.
    Inventors: Hiromasa Fujii, Hiroto Yasuda, Hiroki Harada, Shunji Miura, Hidetoshi Kayama
  • Publication number: 20150128190
    Abstract: Disclosed is a method and server for generating a video program recommendation for a particular video program. The method may include the following steps of: extracting key information from an electronic program guide of a particular video program and the particular video program; searching for contents related with the key information on a public social media by using the key information, and obtaining search results; extracting an abstract from the search results as an inquiry request; searching for video programs in a broadcasting video library and an Internet video library based on the inquiry request, and using obtained search results as a video program recommendation for the particular video program; and storing the video program recommendation in association with the particular video program. By using the solutions of the above embodiments, video program recommendations may be generated collectively for video programs at the side of the server.
    Type: Application
    Filed: October 16, 2014
    Publication date: May 7, 2015
    Applicant: NTT DoCoMo, Inc.
    Inventors: Yingjie WANG, Yongsheng ZHANG, Hidetoshi KAYAMA
  • Publication number: 20150128186
    Abstract: The mobile multimedia terminal, a video program recommendation method and a server thereof may include steps of: extracting key information from electronic program guides; crawling social media information related with a terminal user from social media; generating an inquiry at least based on the key information and the crawled social media information; sending the inquiry to a server; searching for video programs in a broadcasting video library and an Internet video library by using the inquiry and taking information of public social media as a constraint condition, as video program recommendations for the terminal, by the server; sending the video program recommendations to the terminal by the server; and presenting the video program recommendations to the user in association with the played programs.
    Type: Application
    Filed: October 16, 2014
    Publication date: May 7, 2015
    Applicant: NTT DoCoMo, Inc.
    Inventors: Yingjie WANG, Yongsheng ZHANG, Hidetoshi KAYAMA
  • Publication number: 20150061966
    Abstract: A reflectarray reflects an incident wave in a desired direction. The reflectarray includes a substrate including a surface which is perpendicular to a predetermined axis; and at least first and second element groups, wherein the first and second element groups are disposed on the substrate, and include elements that reflect a radio wave. The first element group and the second element group reflect the radio wave with corresponding reflection phases which are different from each other. The radio wave enters while forming an angle other than 0 degrees with respect to the predetermined axis. The elements included in the first element group reflect the radio wave with a first reflection phase, and the elements included in the second element group reflect the radio wave with a second reflection phase, wherein the second reflection phase is different from the first reflection phase.
    Type: Application
    Filed: December 3, 2012
    Publication date: March 5, 2015
    Applicant: NTT DOCOMO, INC.
    Inventors: Tamami Maruyama, Yasuhiro Oda, Hidetoshi Kayama, Ngoc Hao Tran, Jiyun Shen
  • Patent number: 8948068
    Abstract: A wireless station in a second communication system, with at least a portion of a first frequency band used in a first communication system and a portion of a second frequency band used in the second communication system being shared or neighboring, the wireless station including a waveform characteristic quantity extracting unit that extracts a waveform characteristic quantity which shows a statistical characteristic of a signal received from the first communication system; a communication parameter determining unit that determines communication parameters to be used for the wireless station in the second communication system depending on a determination result of whether the extracted waveform characteristic quantity is of a predetermined waveform characteristic quantity for reducing an interference; and a transmission and reception unit that transmits and receives a wireless communication signal in the second communication system in accordance with the determined communication parameters.
    Type: Grant
    Filed: January 13, 2012
    Date of Patent: February 3, 2015
    Assignee: NTT DOCOMO, INC.
    Inventors: Hiroki Harada, Hiromasa Fujii, Shunji Miura, Hidetoshi Kayama
  • Publication number: 20150022414
    Abstract: A method of designing a reflectarray including a substrate having a surface perpendicular to a predetermined axis, wherein elements are disposed on the substrate. The method obtains a reflection phase of the elements as a function of a design parameter such as element spacing, when a radio wave enters the arranged elements, and stores a relationship between the reflection phase and the design parameter in a memory. Here, the design parameter is equally set for the elements. The method repeatedly determines, for each of the elements, the design parameter of a specific element in accordance with the relationship. The function of the design parameter has a range of almost 360 degrees with respect to a range of the design parameter. The reflection phase is the continuous function of the element spacing such that two resonant points occur at which the reflection phase becomes zero.
    Type: Application
    Filed: December 3, 2012
    Publication date: January 22, 2015
    Applicant: NTT DOCOMO, INC.
    Inventors: Tamami Maruyama, Yasuhiro Oda, Hidetoshi Kayama, Ngoc Hao Tran, Jiyun Shen
  • Publication number: 20150015455
    Abstract: A reflectarray reflects an incident wave in a desired direction. The reflectarray includes a substrate including a surface which is perpendicular to a predetermined axis, and elements disposed on the substrate. A specific element among the elements reflects the incident wave with a specific reflection phase among a plurality of reflection phases. Each of the elements has an element structure including, at least, a patch and a ground plate. Element spacing of first neighboring elements is different from element spacing of second neighboring elements, and a length of a gap between patches of the first neighboring elements is equal to a length of a gap between patches of the second neighboring elements.
    Type: Application
    Filed: December 3, 2012
    Publication date: January 15, 2015
    Applicant: NTT DOCOMO, INC.
    Inventors: Tamami Maruyama, Yasuhiro Oda, Hidetoshi Kayama, Jiyun Shen, Ngoc Hao Tran
  • Publication number: 20140362721
    Abstract: A determination apparatus for determining communication availability in an Orthogonal Frequency Division Multiplexing (OFDM) scheme communication system, the determination apparatus includes a reception unit configured to receive a wireless signal including an OFDM symbol in which a pilot signal is inserted at a constant interval in a frequency axis direction, an obtaining unit configured to obtain a discrete sample signal by sampling the wireless signal, a correlation value calculation unit configured to calculate a correlation value of the discrete sample signal for a time shift amount that is defined in advance according to the constant interval, and a determination unit configured to determine the communication availability in the communication system based on at least a result of determination whether the correlation value for the time shift amount has a peak or not.
    Type: Application
    Filed: February 20, 2013
    Publication date: December 11, 2014
    Applicant: NTT DOCOMO, INC.
    Inventors: Hiroki Harada, Hidetoshi Kayama
  • Patent number: 8903404
    Abstract: A CRS base station (21) includes a transmitting section configured to transmit a synchronization establishment signal, a receiving section configured to receive a random access signal corresponding to the synchronization establishment signal, a determining section configured to determine whether or not the random access signal received by the receiving section has been transmitted from an MCS terminal (12) and an interference reduction processing section configured to perform interference reduction processing on the MCS terminal (12) when the determining section determines that the random access signal has been transmitted from the MCS terminal (12).
    Type: Grant
    Filed: January 30, 2012
    Date of Patent: December 2, 2014
    Assignee: NTT DoCoMo, Inc.
    Inventors: Hiromasa Fujii, Hiroto Yasuda, Hiroki Harada, Shunji Miura, Hidetoshi Kayama
  • Publication number: 20140221030
    Abstract: A CRS base station (21) includes a transmitting section configured to transmit a synchronization establishment signal, a receiving section configured to receive a random access signal corresponding to the synchronization establishment signal, a determining section configured to determine whether or not the random access signal received by the receiving section has been transmitted from an MCS terminal (12) and an interference reduction processing section configured to perform interference reduction processing on the MCS terminal (12) when the determining section determines that the random access signal has been transmitted from the MCS terminal (12).
    Type: Application
    Filed: April 11, 2014
    Publication date: August 7, 2014
    Applicant: NTT DOCOMO, INC.
    Inventors: Hiromasa Fujii, Hiroto Yasuda, Hiroki Harada, Shunji Miura, Hidetoshi Kayama
  • Publication number: 20140112268
    Abstract: The present application provides an information transmission method, an information transmission apparatus, and a base station. The information transmission method comprises: an allocation step of, according to a search space allocation mode, performing search space allocation in a target resource consisting of at least two resource subsets and allocating, for the first user, a first search space capable of transmitting the first user control information, the search space allocation mode being associated with the at least two resource subsets; and a first transmission step of transmitting the first user control information via the first search space so that the first user can acquire the first user control information from the first search space according to the search space allocation mode. According to the present invention, the resource utilization efficiency will be improved.
    Type: Application
    Filed: October 17, 2013
    Publication date: April 24, 2014
    Applicant: NTT DoCoMo, Inc.
    Inventors: Qin MU, Liu Liu, Lan Chen, Hidetoshi Kayama, Kazuaki Takeda
  • Patent number: 8583134
    Abstract: A method for adaptive coordinated transmission in wireless communications includes: determining more than one transmitter for performing coordinated transmission, configuring one of the more than one transmitter to be a serving transmitter with others of the more than one transmitter being cooperating transmitters, and determining more than one receiver; determining, by a cooperating transmitter, a cooperation mode according to measured signal parameters of the more than one receiver after receiving a cooperation request from the serving transmitter, and providing the cooperation mode to the serving transmitter; generating, by each of the more than one transmitter, a transmit signal corresponding to the more than one receiver according to the cooperation mode determined, and transmitting the transmit signal to each of the more than one receiver.
    Type: Grant
    Filed: March 26, 2010
    Date of Patent: November 12, 2013
    Assignee: NTT DoCoMo, Inc.
    Inventors: Xiaolin Hou, Zhan Zhang, Hidetoshi Kayama