Patents by Inventor Masayuki TAKEKAWA
Masayuki TAKEKAWA 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: 12114248Abstract: There is provided a radio communication system comprising: a plurality of movable bodies that support route diversity transmission using a plurality of radio communication lines for data transmission; and an integration controller configured to collect line states of the radio communication lines for each of the plurality of movable bodies. The integration controller is configured to transmit a control signal of the radio communication line to a particular unmanned movable body so as to increase the number of unmanned movable bodies in which the number of radio communication lines whose line states satisfy a quality determination criterion is greater than or equal to a predetermined value, based on the line states of the radio communication lines collected for each of the plurality of movable bodies.Type: GrantFiled: January 10, 2021Date of Patent: October 8, 2024Assignee: HITACHI KOKUSAI ELECTRIC INC.Inventor: Masayuki Takekawa
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Publication number: 20240322967Abstract: A wireless communication control apparatus includes at least one processor, the at least one processor carrying out: an information acquisition process of acquiring information pertaining to a terminal; and a switching control process of carrying out switching, based on the information pertaining to the terminal, between whether a base station causes a plurality of wireless slave stations to function respectively as a plurality of separate cells or causes the plurality of wireless slave stations to function as a single cell.Type: ApplicationFiled: March 15, 2024Publication date: September 26, 2024Applicant: NEC CorporationInventors: Kei YANAGISAWA, Yu TSUMURAYA, Shuhei MIZUGUCHI, Masayuki TAKEKAWA, Sawaka SEKI, Hideki KIKKAWA, Kota TANIZAWA, Eri HOSOO, Kosei KOBAYASHI
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Publication number: 20240073776Abstract: A radio communication system according to the present example comprises: a plurality of unattended movable bodies (M1, M2) that are capable of route diversity transport using a plurality of radio communication lines for data transport; and a regulation station 30 that collects the line states of the radio communication lines for the respective ones of the plurality of unattended movable bodies. On the basis of the line states of the radio communication lines collected for the respective ones of the plurality of movable bodies, the regulation station 30 transmits a control signal of the radio communication line to a particular unattended movable body so as to increase the number of unattended movable bodies for which the number of radio communication lines the line states of which satisfy a quality determination criterion is equal to or greater than a predetermined value (for example, two lines).Type: ApplicationFiled: January 10, 2021Publication date: February 29, 2024Inventor: MASAYUKI TAKEKAWA
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Patent number: 11653297Abstract: An unmanned mobile vehicle M acquires the line quality of a wireless communication line to each of the corresponding base stations having been measured by each mobile station and transmits the line quality to a control station 30. The control station 30 acquires the line quality of a wireless communication line to each of the corresponding mobile stations having been measured by each base station and transmits the line quality to the unmanned mobile vehicle M. When the same communication data is transmitted using two or more wireless communication lines in combination between the control station 30 and the unmanned mobile vehicle M, the transmitting side of the communication data selects two or more wireless communication lines that are used for the transmission of the communication data, on the basis of the line quality of each wireless communication line having been measured by each base station or each mobile station on the receiving side of the communication data.Type: GrantFiled: February 17, 2020Date of Patent: May 16, 2023Assignee: HITACHI KOKUSAI ELECTRIC INC.Inventors: Masayuki Takekawa, Tatsuya Abe
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Publication number: 20230048435Abstract: An unmanned mobile vehicle M acquires the line quality of a wireless communication line to each of the corresponding base stations having been measured by each mobile station and transmits the line quality to a control station 30. The control station 30 acquires the line quality of a wireless communication line to each of the corresponding mobile stations having been measured by each base station and transmits the line quality to the unmanned mobile vehicle M.Type: ApplicationFiled: February 17, 2020Publication date: February 16, 2023Applicant: HITACHI KOKUSAI ELECTRIC INC.Inventors: Masayuki TAKEKAWA, Tatsuya ABE
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Patent number: 10374688Abstract: Provided is a technique for efficiently using a channel bandwidth in a wireless communication system provided with a function for dividing a frequency channel into a plurality of segments and performing relay using the segments that differ from relay section to relay section. In a second scheme, an upstream direction of a first relay section is a DL section, and two segments are used. An upstream direction of a second relay section is a UL section, and two segments are used. That is, 2/3 of an area is used in a frequency-axis direction, and 1/2 of the area is used in a time-axis direction similarly to a first scheme. A data area ratio for the second scheme becomes 1/3. A data area ratio for the first scheme is 1/6. Thus, a throughput for the second scheme is twice a throughput for the first scheme.Type: GrantFiled: February 20, 2015Date of Patent: August 6, 2019Assignee: HITACHI KOKUSAI ELECTRIC INC.Inventors: Kei Yanagisawa, Masayuki Takekawa
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Patent number: 10070406Abstract: A method for adjusting a transmission timing of a terminal station, which is performed at a base station in a Time-Division Duplex communication system, is disclosed. The method includes (a) receiving ranging signals or other reference signals, transmitted from a terminal station; (b) determining whether transmission timing at the terminal station is appropriate or not, by referring to the ranging signals transmitted from the terminal station; and (c) transmitting a value for adjusting the transmission timing at the terminal station. The value of the transmission timing is a value of the integral multiples of the timing offset detection capability of the ranging signal, or a value calculated by referring to the received reference signals, which have assigned with a different interval from an interval of the ranging signals.Type: GrantFiled: September 20, 2016Date of Patent: September 4, 2018Assignee: Hitachi Kokusai Electric, Inc.Inventors: Masayuki Takekawa, Keigo Hasegawa
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Publication number: 20180048379Abstract: Provided is a technique for efficiently using a channel bandwidth in a wireless communication system provided with a function for dividing a frequency channel into a plurality of segments and performing relay using the segments that differ from relay section to relay section. In a second scheme, an upstream direction of a first relay section is a DL section, and two segments are used. An upstream direction of a second relay section is a UL section, and two segments are used. That is, ? of an area is used in a frequency-axis direction, and ½ of the area is used in a time-axis direction similarly to a first scheme. A data area ratio for the second scheme becomes ?. A data area ratio for the first scheme is ?. Thus, a throughput for the second scheme is twice a throughput for the first scheme.Type: ApplicationFiled: February 20, 2015Publication date: February 15, 2018Applicant: HITACHI KOKUSAI ELECTRIC INC.Inventors: Kei YANAGISAWA, Masayuki TAKEKAWA
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Patent number: 9781719Abstract: The present invention introduces a multichannel MAC into a white-space-using system. A base station and a terminal station are each configured from a plurality of wireless communication units and centralized control units thereof. Each of the wireless communication units wirelessly transmits/receives for one channel. The base station operates one or more channels according to white-space-channel status, and is assigned to a terminal station. When operating a plurality of channels, it is possible to select a redundancy mode for assigning data by duplicating the terminal-station data in a plurality of channels, and a high-speed mode for dividing the data and distributing the data among the plurality of channels.Type: GrantFiled: August 29, 2013Date of Patent: October 3, 2017Assignee: HITACHI KOKUSAI ELECTRIC INC.Inventors: Keigo Hasegawa, Keat Beng Toh, Masayuki Takekawa, Kei Yanagisawa, Madoka Tanaka
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Patent number: 9743412Abstract: In the wireless communication system, each of a base station 11 and a terminal station 12 obtains its location information, and upon establishment of synchronization, the terminal station 12 transmits a terminal station free channel list and its location information by extremely low power wireless communication, and the base station 11 compares a base station free channel list created based on information from a database 40 with the terminal station free channel list from the terminal station 12, and determines, when there is a common free channel, the free channel as uplink/downlink channels and determines, when there is no common free channel, an uplink channel and a downlink channel as different channels, calculates a base station-terminal station distance from the location information of the base station 11 and the location information of the terminal station 12, and determines terminal station's uplink transmission power based on the distance.Type: GrantFiled: January 16, 2014Date of Patent: August 22, 2017Assignee: Hitachi Kokusai Electric, Inc.Inventors: Kei Yanagisawa, Keigo Hasegawa, Masayuki Takekawa
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Patent number: 9713171Abstract: Provided is a wireless communication system that is capable of preventing interference between secondary use systems that do not use a database. The wireless communication system uses a white space for opposing communication between a base station and a terminal station. At startup, the base station transmits a preamble over a cycle that is n-times a frame length (where n is an integer 2 or greater), changes a set frequency channel if ranging is not detected from a terminal station within a fixed time interval, and begins normal operation using the set frequency channel if ranging is detected. At startup, the terminal station detects a preamble within a received signal, changes a set frequency channel if a peak is detected at each frame length, and transmits a ranging signal if peaks are detected for cycles that are n-times the frame length and peaks are not detected for other cycles.Type: GrantFiled: September 5, 2014Date of Patent: July 18, 2017Assignee: Hitachi Kokusai Electric Inc.Inventors: Kei Yanagisawa, Masayuki Takekawa, Keigo Hasegawa
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Patent number: 9661644Abstract: There is provided a wireless communication system that is capable of preventing interference with a primary use system caused by a CPE emitting radio waves at a frequency which is not a transmittable frequency before acquiring a list of transmittable frequencies based on its position information. In a wireless communication system that uses white space, a BS 10 and a CPE 22 store a specific frequency which is guaranteed to not interfere with a primary user. The BS 10 regularly switches between a first period when communication is performed at an operating frequency that uses white space and a second period when communication is performed at the specific frequency.Type: GrantFiled: March 28, 2014Date of Patent: May 23, 2017Assignee: Hitachi Kokusai Electric, Inc.Inventors: Masayuki Takekawa, Keigo Hasegawa, Kei Yanagisawa
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Patent number: 9609523Abstract: Disclosed is a wireless communication system using white spaces and a base station that does not have its own backhaul, starts wireless communications without radiating radio waves of frequencies causing interference with primary users. A BS being in isolation starts a wireless communication with a CPE, connected to the internet, so as to access a database to acquire a list of frequencies available for transmission. The BS uses a predetermined frequency to perform the wireless communication with the CPE, and acquires, via this wireless communication, the list of frequencies available for transmission. Thereafter, the BS performs wireless communications with the CPE and with another CPE on the basis of the acquired list of frequencies available for transmission. The BS can hold, in advance, information of the predetermined frequency for which it has been estimated that the BS will cause no interference with the wireless communications of the primary users.Type: GrantFiled: September 10, 2014Date of Patent: March 28, 2017Assignee: HITACHI KOKUSAI ELECTRIC, INC.Inventors: Masayuki Takekawa, Keigo Hasegawa, Kei Yanagisawa, Keat Beng Toh
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Publication number: 20170013582Abstract: A method for adjusting a transmission timing of a terminal station, which is performed at a base station in a Time-Division Duplex communication system, is disclosed. The method includes (a) receiving ranging signals or other reference signals, transmitted from a terminal station; (b) determining whether transmission timing at the terminal station is appropriate or not, by referring to the ranging signals transmitted from the terminal station; and (c) transmitting a value for adjusting the transmission timing at the terminal station. The value of the transmission timing is a value of the integral multiples of the timing offset detection capability of the ranging signal, or a value calculated by referring to the received reference signals, which have assigned with a different interval from an interval of the ranging signals.Type: ApplicationFiled: September 20, 2016Publication date: January 12, 2017Inventors: Masayuki TAKEKAWA, Keigo HASEGAWA
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Patent number: 9467867Abstract: To establish a wireless link with a terminal station without interfering with a primary user of a frequency, in a system and method in which a base station accesses a management apparatus for managing the frequency available for wireless communication via the wireless link with the terminal station.Type: GrantFiled: November 13, 2014Date of Patent: October 11, 2016Assignee: HITACHI KOKUSAI ELECTRIC, INC.Inventors: Keigo Hasegawa, Masayuki Takekawa
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Publication number: 20160277938Abstract: To establish a wireless link with a terminal station without interfering with a primary user of a frequency, in a system and method in which a base station accesses a management apparatus for managing the frequency available for wireless communication via the wireless link with the terminal station.Type: ApplicationFiled: November 13, 2014Publication date: September 22, 2016Inventors: Keigo HASEGAWA, Masayuki TAKEKAWA
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Patent number: 9438329Abstract: A wireless communication terminal includes: an array antenna; a MAC processing section, provided to detect a first order system, that interprets information on a quiet period that the base station has informed of the MAC processing section in advance and generates a quiet period signal; a synthesizing section that weights signals received by antennas of the array antenna by using weighting coefficients, and combines the signals to produce a synthetic signal; and an array antenna control section that optimizes the weighting coefficients so as to reduce an interference signal received from the array antenna, over a period of presence of the quiet period signal. The optimized weighting coefficients are applied while downstream signals from the base station are being received, but are not applied while the primary usage system is being detected.Type: GrantFiled: November 19, 2013Date of Patent: September 6, 2016Assignee: Hitachi Kokusai Electric Inc.Inventors: Keat Beng Toh, Masayuki Takekawa, Keigo Hasegawa
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Publication number: 20160227418Abstract: Disclosed is a wireless communication system using white spaces and a base station that does not have its own backhaul, starts wireless communications without radiating radio waves of frequencies causing interference with primary users. A BS being in isolation starts a wireless communication with a CPE, connected to the internet, so as to access a database to acquire a list of frequencies available for transmission. The BS uses a predetermined frequency to perform the wireless communication with the CPE, and acquires, via this wireless communication, the list of frequencies available for transmission. Thereafter, the BS performs wireless communications with the CPE and with another CPE on the basis of the acquired list of frequencies available for transmission. The BS can hold, in advance, information of the predetermined frequency for which it has been estimated that the BS will cause no interference with the wireless communications of the primary users.Type: ApplicationFiled: September 10, 2014Publication date: August 4, 2016Applicant: HITACHI KOKUSAI ELECTRIC INC.Inventors: Masayuki TAKEKAWA, Keigo HASEGAWA, Kei YANAGISAWA, Keat Beng TOH
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Publication number: 20160227584Abstract: Provided is a wireless communication system that is capable of preventing interference between secondary use systems that do not use a database. The wireless communication system uses a white space for opposing communication between a base station and a terminal station. At startup, the base station transmits a preamble over a cycle that is n-times a frame length (where n is an integer 2 or greater), changes a set frequency channel if ranging is not detected from a terminal station within a fixed time interval, and begins normal operation using the set frequency channel if ranging is detected. At startup, the terminal station detects a preamble within a received signal, changes a set frequency channel if a peak is detected at each frame length, and transmits a ranging signal if peaks are detected for cycles that are n-times the frame length and peaks are not detected for other cycles.Type: ApplicationFiled: September 5, 2014Publication date: August 4, 2016Inventors: Kei YANAGISAWA, Masayuki TAKEKAWA, Keigo HASEGAWA
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Publication number: 20160135196Abstract: There is provided a wireless communication system that is capable of preventing interference with a primary use system caused by a CPE emitting radio waves at a frequency which is not a transmittable frequency before acquiring a list of transmittable frequencies based on its position information. In a wireless communication system that uses white space, a BS 10 and a CPE 22 store a specific frequency which is guaranteed to not interfere with a primary user. The BS 10 regularly switches between a first period when communication is performed at an operating frequency that uses white space and a second period when communication is performed at the specific frequency.Type: ApplicationFiled: March 28, 2014Publication date: May 12, 2016Inventors: Masayuki TAKEKAWA, Keigo Hasegawa, Kei YANAGISAWA