Patents by Inventor Tatsunori OBARA
Tatsunori OBARA 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).
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Patent number: 10993241Abstract: In order to prevent wireless resources from becoming scarce in a Sidelink V2X communication, a UE (10) that carries out the Sidelink V2X communication causes: a free resource search unit (105) to search for free resources within a first resource range; a transmission processing unit (107) to transmit a first transmission packet by using the free resources within the first resource range; a transmission inhibition timer unit (108) to set transmission inhibition time which is time for inhibiting start of a second resource range after the transmission of the first transmission packet within the first resource range; and the free resource search unit (105) to search for free resources within the second resource range after the expiration of the transmission inhibition time.Type: GrantFiled: March 31, 2017Date of Patent: April 27, 2021Assignee: NTT DOCOMO, INC.Inventors: Tatsunori Obara, Riichi Kudou
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Patent number: 10708821Abstract: A management apparatus in a wireless communication system including multiple transmission points transmitting reference signals, the management apparatus managing the transmission points, and a mobile station, includes: a management unit for managing first and second clusters generated by grouping one or more transmission points used to communicate with the mobile station among the multiple transmission points; and a control unit for controlling allocation of the reference signals transmitted from the multiple transmission points in the first and second clusters. The management unit detects that multiple cells formed by the transmission points in the first cluster overlap some of multiple cells formed by the transmission points in the second cluster. When the management unit detects the overlap, the control unit allocates the orthogonal reference signals to the multiple cells formed by the transmission points in the first cluster and the multiple cells formed by the transmission points in the second cluster.Type: GrantFiled: February 16, 2017Date of Patent: July 7, 2020Assignee: NTT DOCOMO, INC.Inventors: Tatsuki Okuyama, Satoshi Suyama, Tatsunori Obara, Yukihiko Okumura
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Patent number: 10700756Abstract: A user equipment UE includes: a measurer that measures, for each of a plurality of candidate beams, a benchmark pertaining to communication quality; a comparer that compares the benchmark with a first threshold value and a second threshold value; and a feedback unit that transmits the benchmark to the base station as feedback information pertaining to an interference beam if the benchmark is the first threshold value or higher and lower than the second threshold value, transmits the benchmark to the base station as feedback information pertaining to a desired beam if the benchmark is the second threshold value or higher, and transmits no feedback information to the base station if the benchmark is lower than the first threshold value, based on the comparison results of the comparer.Type: GrantFiled: February 1, 2017Date of Patent: June 30, 2020Assignee: NTT DOCOMO, INC.Inventors: Tatsuki Okuyama, Satoshi Suyama, Tatsunori Obara, Yukihiko Okumura
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Patent number: 10637543Abstract: There is provided a base station that supports multi-user MIMO and performs communication with a plurality of mobile stations of a radio communication system including the base station and the plurality of mobile stations, the base station including a determination unit that determines a number of a plurality of streams to be transmitted to each of the plurality of mobile stations and parameters to be applied to each of the plurality of streams to be transmitted to each of the plurality of mobile stations based on a channel estimation value for each of the plurality of mobile stations, and a transmitter that generates a determined number of streams according to the parameters determined by the determination unit to be transmitted to the respective plurality of mobile stations.Type: GrantFiled: March 8, 2017Date of Patent: April 28, 2020Assignee: NTT DOCOMO, INC.Inventors: Tatsunori Obara, Satoshi Suyama, Tatsuki Okuyama, Yukihiko Okumura
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Patent number: 10637542Abstract: Provided is a base station for communicating with mobile stations of a radio communication system including the base station and mobile stations including an obtaining unit that obtains a channel matrix for each mobile stations; a selector that selects, among the mobile stations, a combination of two or more mobile stations with which communication based on multi-user MIMO is to be performed; and a communication unit that communicates, based on multi-user MIMO, with the two or more mobile stations of the selected combination, wherein the selector calculates, for each of all combinations of two mobile stations of the two or more mobile stations, a correlation value between the channel matrices for the two mobile stations, and selects the combination of the two or more mobile stations, so that, for all the combinations of the two mobile stations, the correlation values is less than or equal to a predetermined value.Type: GrantFiled: February 21, 2017Date of Patent: April 28, 2020Assignee: NTT DOCOMO, INC.Inventors: Tatsuki Okuyama, Satoshi Suyama, Tatsunori Obara, Yukihiko Okumura
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Patent number: 10623910Abstract: A server device for determining, on the basis of a communication cost in a communication area in which at least one terminal is communicatable and the position of the at least one terminal, a first terminal to which uplink data is to be transmitted in a first communication area, in which the communication cost is less than a threshold, transmitting to the first terminal an indication for uplink data transmission in the first communication area, and receiving uplink data from the first terminal.Type: GrantFiled: September 27, 2017Date of Patent: April 14, 2020Assignee: NTT DOCOMO, INC.Inventors: Tatsunori Obara, Shinpei Yasukawa, Riichi Kudou
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Publication number: 20200077410Abstract: In order to prevent wireless resources from becoming scarce in a Sidelink V2X communication, a UE (10) that carries out the Sidelink V2X communication causes: a free resource search unit (105) to search for free resources within a first resource range; a transmission processing unit (107) to transmit a first transmission packet by using the free resources within the first resource range; a transmission inhibition timer unit (108) to set transmission inhibition time which is time for inhibiting start of a second resource range after the transmission of the first transmission packet within the first resource range; and the free resource search unit (105) to search for free resources within the second resource range after the expiration of the transmission inhibition time.Type: ApplicationFiled: March 31, 2017Publication date: March 5, 2020Applicant: NTT DOCOMO, INC.Inventors: Tatsunori Obara, Riichi Kudou
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Patent number: 10542485Abstract: A base station transmits first discovery signals in different transmission directions from the base station through beamforming; transmits, for one or more first transmission directions corresponding to one or more first discovery signals reported from the mobile station, second discovery signals in second transmission directions within a predetermined range from the first transmission direction; and, for transmitting the second discovery signal, transmits the second discovery signal by multiplying, by a correction precoding vector for adding, to the first transmission direction, a transmission angle difference between the first transmission direction within the predetermined range from the second discovery signal and a second transmission direction of the second discovery signal to be transmitted, and by performing beamforming for the second discovery signal to which the correction precoding vector is multiplied, using a first weight matrix for beamforming in the first transmission direction within the predeType: GrantFiled: March 8, 2017Date of Patent: January 21, 2020Assignee: NTT DOCOMO, INC.Inventors: Tatsunori Obara, Satoshi Suyama, Tatsuki Okuyama, Yukihiko Okumura
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Patent number: 10505593Abstract: A wireless communication system includes: a plurality of first wireless stations; a plurality of second wireless stations; and a management apparatus configured to manage the plurality of first wireless stations and the plurality of second wireless stations. The management apparatus includes a selection unit that selects a plurality of antennas to be used to transmit reference signals from a plurality of antennas included in the plurality of first wireless stations or a plurality of antennas included in the plurality of second wireless stations, and an instruction unit that instructs the plurality of first wireless stations or the plurality of second wireless stations to transmit reference signals using the plurality of antennas used to transmit the reference signals and selected by the selection unit.Type: GrantFiled: March 2, 2017Date of Patent: December 10, 2019Assignee: NTT DOCOMO, INC.Inventors: Tatsuki Okuyama, Satoshi Suyama, Tatsunori Obara, Yukihiko Okumura
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Publication number: 20190349713Abstract: A server device for determining, on the basis of a communication cost in a communication area in which at least one terminal is communicatable and the position of the at least one terminal, a first terminal to which uplink data is to be transmitted in a first communication area, in which the communication cost is less than a threshold, transmitting to the first terminal an indication for uplink data transmission in the first communication area, and receiving uplink data from the first terminal.Type: ApplicationFiled: September 27, 2017Publication date: November 14, 2019Applicant: NTT DOCOMO, INC.Inventors: Tatsunori Obara, Shinpei Yasukawa, Riichi Kudou
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Patent number: 10425255Abstract: There is provided an estimation device including an acquisition unit that acquires a channel estimation value for each combination of all of a plurality of combinations between a plurality of transmission antenna elements included in a base station and a plurality of reception antenna elements included in a mobile station; and an estimation unit that calculates a channel impulse response for each combination of all of the plurality of combinations between the plurality of transmission antenna elements and the plurality of reception antenna elements using the channel estimation values, and that estimates power delay profile by averaging, over all the combinations of the plurality of combinations between the plurality of transmission antenna elements and the plurality of reception antenna elements, power values for the respective combinations that are calculated from the calculated channel impulse responses for the respective combinations.Type: GrantFiled: March 9, 2017Date of Patent: September 24, 2019Assignee: NTT DOCOMO, INC.Inventors: Tatsunori Obara, Satoshi Suyama, Tatsuki Okuyama, Yukihiko Okumura
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Publication number: 20190281533Abstract: A wireless terminal device comprising: a storage unit that holds connection ID mapping information having associated therein a connection ID and at least one logical connection destination; a communications unit that receives control information including the connection ID and communications control information for the logical connection destination; and a control unit that specifies a logical connection destination corresponding to the connection ID included in the control information received by the communications unit, on the basis of the connection ID mapping information, and performs processing on the specified logical connection destination, on the basis of the communications control information.Type: ApplicationFiled: October 30, 2017Publication date: September 12, 2019Applicant: NTT DOCOMO, INC.Inventors: Shinpei Yasukawa, Satoshi Nagata, Riichi Kudou, Tatsunori Obara
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Publication number: 20190097843Abstract: There is provided an estimation device including an acquisition unit that acquires a channel estimation value for each combination of all of a plurality of combinations between a plurality of transmission antenna elements included in a base station and a plurality of reception antenna elements included in a mobile station; and an estimation unit that calculates a channel impulse response for each combination of all of the plurality of combinations between the plurality of transmission antenna elements and the plurality of reception antenna elements using the channel estimation values, and that estimates power delay profile by averaging, over all the combinations of the plurality of combinations between the plurality of transmission antenna elements and the plurality of reception antenna elements, power values for the respective combinations that are calculated from the calculated channel impulse responses for the respective combinations.Type: ApplicationFiled: March 9, 2017Publication date: March 28, 2019Applicant: NTT DOCOMO, INC.Inventors: Tatsunori Obara, Satoshi Suyama, Tatsuki Okuyama, Yukihiko Okumura
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Publication number: 20190082354Abstract: A management apparatus in a wireless communication system including multiple transmission points transmitting reference signals, the management apparatus managing the transmission points, and a mobile station, includes: a management unit for managing first and second clusters generated by grouping one or more transmission points used to communicate with the mobile station among the multiple transmission points; and a control unit for controlling allocation of the reference signals transmitted from the multiple transmission points in the first and second clusters. The management unit detects that multiple cells formed by the transmission points in the first cluster overlap some of multiple cells formed by the transmission points in the second cluster. When the management unit detects the overlap, the control unit allocates the orthogonal reference signals to the multiple cells formed by the transmission points in the first cluster and the multiple cells formed by the transmission points in the second cluster.Type: ApplicationFiled: February 16, 2017Publication date: March 14, 2019Applicant: NTT DOCOMO, INC.Inventors: Tatsuki Okuyama, Satoshi Suyama, Tatsunori Obara, Yukihiko Okumura
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Publication number: 20190075515Abstract: A base station transmits first discovery signals in different transmission directions from the base station through beamforming; transmits, for one or more first transmission directions corresponding to one or more first discovery signals reported from the mobile station, second discovery signals in second transmission directions within a predetermined range from the first transmission direction; and, for transmitting the second discovery signal, transmits the second discovery signal by multiplying, by a correction precoding vector for adding, to the first transmission direction, a transmission angle difference between the first transmission direction within the predetermined range from the second discovery signal and a second transmission direction of the second discovery signal to be transmitted, and by performing beamforming for the second discovery signal to which the correction precoding vector is multiplied, using a first weight matrix for beamforming in the first transmission direction within the predeType: ApplicationFiled: March 8, 2017Publication date: March 7, 2019Applicant: NTT DOCOMO, INC.Inventors: Tatsunori Obara, Satoshi Suyama, Tatsuki Okuyama, Yukihiko Okumura
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Publication number: 20190074870Abstract: A wireless communication system includes: a plurality of first wireless stations; a plurality of second wireless stations; and a management apparatus configured to manage the plurality of first wireless stations and the plurality of second wireless stations. The management apparatus includes a selection unit that selects a plurality of antennas to be used to transmit reference signals from a plurality of antennas included in the plurality of first wireless stations or a plurality of antennas included in the plurality of second wireless stations, and an instruction unit that instructs the plurality of first wireless stations or the plurality of second wireless stations to transmit reference signals using the plurality of antennas used to transmit the reference signals and selected by the selection unit.Type: ApplicationFiled: March 2, 2017Publication date: March 7, 2019Applicant: NTT DOCOMO, INC.Inventors: Tatsuki Okuyama, Satoshi Suyama, Tatsunori Obara, Yukihiko Okumura
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Publication number: 20190074874Abstract: There is provided a base station that supports multi-user MIMO and performs communication with a plurality of mobile stations of a radio communication system including the base station and the plurality of mobile stations, the base station including a determination unit that determines a number of a plurality of streams to be transmitted to each of the plurality of mobile stations and parameters to be applied to each of the plurality of streams to be transmitted to each of the plurality of mobile stations based on a channel estimation value for each of the plurality of mobile stations, and a transmitter that generates a determined number of streams according to the parameters determined by the determination unit to be transmitted to the respective plurality of mobile stations.Type: ApplicationFiled: March 8, 2017Publication date: March 7, 2019Applicant: NTT DOCOMO, INC.Inventors: Tatsunori Obara, Satoshi Suyama, Tatsuki Okuyama, Yukihiko Okumura
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Publication number: 20180331746Abstract: A user equipment UE includes: a measurer that measures, for each of a plurality of candidate beams, a benchmark pertaining to communication quality; a comparer that compares the benchmark with a first threshold value and a second threshold value; and a feedback unit that transmits the benchmark to the base station as feedback information pertaining to an interference beam if the benchmark is the first threshold value or higher and lower than the second threshold value, transmits the benchmark to the base station as feedback information pertaining to a desired beam if the benchmark is the second threshold value or higher, and transmits no feedback information to the base station if the benchmark is lower than the first threshold value, based on the comparison results of the comparer.Type: ApplicationFiled: February 1, 2017Publication date: November 15, 2018Applicant: NTT DOCOMO, INC.Inventors: Tatsuki Okuyama, Satoshi Suyama, Tatsunori Obara, Yukihiko Okumura
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Publication number: 20180316397Abstract: Provided is a base station for communicating with mobile stations of a radio communication system including the base station and mobile stations including an obtaining unit that obtains a channel matrix for each mobile stations; a selector that selects, among the mobile stations, a combination of two or more mobile stations with which communication based on multi-user MIMO is to be performed; and a communication unit that communicates, based on multi-user MIMO, with the two or more mobile stations of the selected combination, wherein the selector calculates, for each of all combinations of two mobile stations of the two or more mobile stations, a correlation value between the channel matrices for the two mobile stations, and selects the combination of the two or more mobile stations, so that, for all the combinations of the two mobile stations, the correlation values is less than or equal to a predetermined value.Type: ApplicationFiled: February 21, 2017Publication date: November 1, 2018Applicant: NTT DOCOMO, INC.Inventors: Tatsuki Okuyama, Satoshi Suyama, Tatsunori Obara, Yukihiko Okumura
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Patent number: 10116370Abstract: A number LR of receive beamforming circuits provided in a receive beamformer execute receive beamforming (NR/LR) times with respect to a received signal vector received by NR reception antennas AR, thereby generating a receive beamforming (BF) output vector having NR receive BF output components. A calculation processor calculates a reception power for each of the NR receive BF output components, selects LR receive BF output components in decreasing order of reception power, and determines a suitable receive BF weight matrix including LR reception orthogonal BF weight vectors corresponding to the selected receive BF output components.Type: GrantFiled: March 23, 2016Date of Patent: October 30, 2018Assignee: NTT DOCOMO, INC.Inventors: Tatsunori Obara, Satoshi Suyama, Jiyun Shen, Yukihiko Okumura