Patents by Inventor Daichi Imamura
Daichi Imamura 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: 12556298Abstract: Provided is a sequence allocation method capable of reducing inter-cell interference of a reference signal when a ZC sequence is used as the reference signal in a mobile communication system. In the sequence allocation method, R×M sequences specified by a ZC sequence number r (r=1 to R) and a cyclic shift sequence number m (m=1 to M) are divided into a plurality of sequence groups X (X=1 to R) in accordance with the transmission band width of the reference signal, so that the ZC sequence is allocated to each cell in each sequence group unit. When it is assumed that R=9 and M=6, the number of sequences is 54. Each of the sequence groups is formed by two sequences. Accordingly, the number of sequence groups is 27. The 27 types of sequence groups are allocated to each cell.Type: GrantFiled: September 24, 2024Date of Patent: February 17, 2026Assignee: Panasonic Holdings CorporationInventors: Yoshihiko Ogawa, Daichi Imamura, Sadaki Futagi, Tomofumi Takata
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Patent number: 12432002Abstract: Provided are a wireless communication apparatus and a reference signal generating method, wherein inter-cell interference is reduced inside and outside a CoMP set. A CoMP mode setting unit (101) sets whether the terminal (100) thereof is a CoMP terminal or a Non-CoMP terminal. When the terminal (100) is set as a Non-CoMP terminal, the hopping pattern calculating unit (104) calculates a ZC sequence number to be used as the transmission timing, from among all the ZC sequence numbers that can be used within the system. When the terminal (100) is set as a CoMP terminal, the hopping pattern calculating unit (104) calculates a ZC sequence number to be used as the transmission timing, by hopping the ZC sequence numbers to be used within the CoMP set. A ZC sequence generating unit (105) generates a ZC sequence to be used as an SRS, using the calculated ZC sequence number.Type: GrantFiled: January 9, 2024Date of Patent: September 30, 2025Assignee: Sun Patent TrustInventors: Takashi Iwai, Daichi Imamura, Akihiko Nishio, Yoshihiko Ogawa, Masaru Fukuoka
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Patent number: 12418354Abstract: A radio communication device capable of randomizing both inter-cell interference and intra-cell interference. In this device, a spreading section primarily spreads a response signal in a ZAC sequence set by a control unit. A spreading section secondarily spreads the primarily spread response signal in a block-wise spreading code sequence set by the control unit. The control unit controls the cyclic shift amount of the ZAC sequence used for the primary spreading in the spreading section and the block-wise spreading code sequence used for the secondary spreading in the spreading section according to a set hopping pattern. The hopping pattern set by the control unit is made up of two hierarchies. An LB-based hopping pattern different for each cell is defined in the first hierarchy in order to randomize the inter-cell interference. A hopping pattern different for each mobile station is defined in the second hierarchy to randomize the intra-cell interference.Type: GrantFiled: January 18, 2024Date of Patent: September 16, 2025Assignee: Panasonic Holdings CorporationInventors: Seigo Nakao, Daichi Imamura, Katsuhiko Hiramatsu
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Patent number: 12362851Abstract: A base station communicates with a terminal, for which an uplink component carrier and downlink component carriers are configured. The base station adjusts a payload size of control information, transmitted in a downlink control channel, based on a basic payload size, and maps the control information onto a search space in at least one of the downlink component carriers. The basic payload size of the control information mapped onto a search space in a primary downlink component carrier is based on a number of information bits obtained from a bandwidth of the primary downlink component carrier, and on a number of information bits obtained from a bandwidth of the uplink component carrier. The basic payload size of the control information mapped onto a search space in a non-primary downlink component carrier is based on a number of information bits obtained from a bandwidth of the non-primary downlink component carrier.Type: GrantFiled: July 15, 2024Date of Patent: July 15, 2025Assignee: Sun Patent TrustInventors: Seigo Nakao, Akihiko Nishio, Daichi Imamura
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Patent number: 12349145Abstract: A base station is disclosed, including an information size adjusting section configured to adjust a size of control information based on a first basic information size of control information mapped on a user equipment (UE) specific search space in a first component carrier. The base station also includes a transmitter configured to transmit the control information mapped on the UE specific search space. A first determination method for determining the first basic information size is different from a second determination method for determining a second basic information size of control information mapped on a common search space in the first component carrier. The first determination method for determining the first basic information size is different from a third determination method for determining a third basic information size of control information mapped on a search space in a second component carrier that is different from the first component carrier.Type: GrantFiled: January 11, 2024Date of Patent: July 1, 2025Assignee: Sun Patent TrustInventors: Seigo Nakao, Daichi Imamura, Takahisa Aoyama
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Publication number: 20250158788Abstract: A wireless communication base station apparatus which is able to prevent deterioration in the throughput of LTE terminals even when LTE terminals and LTE+ terminals coexist. In this apparatus, based on the mapping pattern of the reference signals used only in LTE+ terminals, a setting unit sets, in each subframe, the resource block groups where the reference signals used only by the LTE+ terminals are mapped. For symbols mapped to the antennas, an mapping unit maps, to all the resource blocks within one frame, cell specific reference signals used for both LTE terminals and LTE+ terminals. For the symbols mapped to the antennas, the mapping unit maps, to the plurality of resource blocks, of which part of the resource block groups is comprised, in the same subframe within one frame, the cell specific reference signals used only for LTE+ terminals, based on the setting results inputted from the setting unit.Type: ApplicationFiled: January 14, 2025Publication date: May 15, 2025Inventors: Akihiko NISHIO, Seigo NAKAO, Daichi IMAMURA
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Publication number: 20250150232Abstract: Disclosed are a wireless transmitter and a reference signal transmission method that improve channel estimation accuracy. In a terminal, which transmits a reference signal using n (n is a non-negative integer 2 or greater) band blocks (which correspond to clusters here), which are disposed with spaces therebetween in a frequency direction, a reference signal controller switches the reference signal formation method of a reference signal generator between a first formation method and a second formation method based on the number (n) of band blocks. In addition, a threshold value setting unit adjusts a switching threshold value based on the frequency spacing between band blocks. Thus, the reference signal formation method can be selected with good accuracy and, as a result, channel estimation accuracy is further improved.Type: ApplicationFiled: January 7, 2025Publication date: May 8, 2025Inventors: Takashi IWAI, Sadaki FUTAGI, Tomohumi TAKATA, Daichi IMAMURA, Yoshihiko OGAWA
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Publication number: 20250151067Abstract: Provided are a terminal device and a retransmission control method that make it possible to minimize increases in overhead in an uplink control channel (PUCCH), even if channel selection is used as the method to transmit response signals during carrier-aggregation communication using a plurality of downlink unit bands. On the basis of the generation status of uplink data and error-detection results obtained by a CRC unit, a control unit in the provided terminal uses response signal transmission rules to control the transmission of response signals or uplink control signals that indicate the generation of uplink data. If an uplink control signal and a response signal are generated simultaneously within the same transmission time unit, the control unit changes the resources allocated to the response signal and/or the phase point of the response signal in accordance with the number and position of ACKs within the error-detection result pattern.Type: ApplicationFiled: January 13, 2025Publication date: May 8, 2025Inventors: Seigo NAKAO, Akihiko NISHIO, Ayako HORIUCHI, Daichi IMAMURA
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Publication number: 20250150989Abstract: A radio communication apparatus is provided, which includes a receiver and a controller. The receiver, in operation, receives a first power headroom (PHR), which is obtained by subtracting a transmit power for a data channel from a maximum transmit power at a mobile station and which is transmitted from the mobile station, and receives a second PHR, which is obtained by subtracting the transmit power for the data channel and a transmit power for a control channel from the maximum transmit power at the mobile station and which is transmitted from the mobile station. The controller, in operation, selectively sets a simultaneous transmission of the data channel and the control channel in different frequency bands to be performed by the mobile station. When the data channel and the control channel are simultaneously transmitted in different frequency bands from the mobile station, the second PHR is obtained and transmitted from the mobile station.Type: ApplicationFiled: January 9, 2025Publication date: May 8, 2025Inventors: Takashi IWAI, Akihiko NISHIO, Daichi IMAMURA, Yoshihiko OGAWA, Atsushi MATSUMOTO
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Publication number: 20250126544Abstract: An integrated circuit includes circuitry, which, in operation, controls transmitting downlink data to a terminal apparatus; receiving a plurality of transport blocks which are transmitted in a same time period using a same frequency band in a spatial multiplexing scheme, wherein a same acknowledgement information (ACK/NACK) relating to an error detection result of the downlink data is scrambled with different scrambling schemes respectively for the plurality of transport blocks and the respectively scrambled ACK/NACK is multiplexed with data on respective ones of the plurality of transport blocks, and channel quality information (CQI) of a downlink channel is multiplexed with the data on only one transport block of the plurality of transport blocks by the terminal apparatus; and extracting the ACK/NACK and the CQI from the received plurality of transport blocks.Type: ApplicationFiled: December 23, 2024Publication date: April 17, 2025Inventors: Yoshihiko OGAWA, Seigo NAKAO, Akihiko NISHIO, Masayuki HOSHINO, Daichi IMAMURA, Atsushi SUMASU
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Patent number: 12279236Abstract: Where first and second reference signals for a first and second communication system, respectively, are transmitted, resources that affect a reception apparatus compatible only with the first communication system can be minimized, and the throughput can be prevented from being deteriorated. As resources for a reference signal CSI-RS for LTE-A, last half symbols in a time direction of a resource unit RB/Sub-frame defined in a frequency-time domain are used, and the CSI-RS is allocated in a position up to the last two symbols or in the last symbol, or the like, of a particular RB/Sub-frame and transmitted when a reference signal 4RS for LTE is transmitted to a reception apparatus in addition to transmitting CSI-RS for LTE-A. The reception apparatus receives CSI-RS allocated in the last half symbol of RB/Sub-frame based on CSI-RS allocation information, measures channel quality by using this CSI-RS, and transmits and reports feedback information.Type: GrantFiled: December 10, 2020Date of Patent: April 15, 2025Assignee: Sun Patent TrustInventors: Masayuki Hoshino, Akihiko Nishio, Seigo Nakao, Daichi Imamura
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Patent number: 12278776Abstract: A communication apparatus includes a receiver and a transmitter. The receiver, in operation, receives from a neighboring cell a reference signal mapped to at least one first resource element. No signal is received from a serving cell on the at least one first resource element. The transmitter, in operation, transmits to a base station measurement information obtained based on the reference signal.Type: GrantFiled: January 19, 2024Date of Patent: April 15, 2025Assignee: Sun Patent TrustInventors: Hui Tong, Ming Xu, Masayuki Hoshino, Daichi Imamura
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Patent number: 12278780Abstract: The present disclosure provides a terminal device that allows constraints on user allocation to be prevented and spread codes to be allocated in a scheduler when non-adaptive HARQ is employed using a PHICH. A codeword generator generates code words by encoding data, a layer mapping unit places each CW in one or a plurality of layers, a DMRS generator generates a reference signal for each layer in which a CW is placed by using any resource among a plurality of resources defined by a mutually orthogonal plurality of OCCs, and an ACK/NACK demodulator receives a response signal indicating a retransmission request. When a response signal requesting retransmission of only a CW placed in a plurality of layers is received, the DMRS generator uses each resource having the same OCC among the plurality of resources for the reference signals generated in the corresponding layers.Type: GrantFiled: March 1, 2024Date of Patent: April 15, 2025Assignee: Sun Patent TrustInventors: Masayuki Hoshino, Akihiko Nishio, Daichi Imamura
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Patent number: 12267193Abstract: Disclosed are a wireless communication base station device and a division number determination method that improves the frequency diversity effect while maintaining channel estimation accuracy regardless of the number of divisions in the frequency domain of a transmission signal from a wireless communication terminal device. A determination unit determines the number of divisions in the frequency domain of a transmission signal from a wireless communication terminal device. Here, the determination unit increases the number of divisions in the frequency domain of the transmission signal from the wireless communication terminal device as the number of pilot blocks included in the transmission signal increases. In addition, a scheduling unit schedules allocation to the frequency resources of the divided transmission signal according to the number of divisions determined by the determination unit.Type: GrantFiled: June 13, 2022Date of Patent: April 1, 2025Assignee: Sun Patent TrustInventors: Yoshihiko Ogawa, Seigo Nakao, Daichi Imamura, Akihiko Nishio, Masayuki Hoshino, Katsuhiko Hiramatsu, Kenichi Miyoshi, Yasuaki Yuda, Sadaki Futagi, Takashi Iwai
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Patent number: 12256335Abstract: Disclosed is a wireless communication device that can suppress an increase in power consumption of a terminal while preventing the degradation of SINR measurement precision resulting from TPC errors in a base station. A terminal controls the transmission power of a second signal by adding an offset to the transmission power of a first signal; an offset-setting unit sets an offset correction value in response to a transmission time gap between a third signal transmitted the previous time and the second signal transmitted this time; and a transmission power control unit controls the transmission power of the second signal using the correction value.Type: GrantFiled: May 22, 2024Date of Patent: March 18, 2025Assignee: Sun Patent TrustInventors: Takashi Iwai, Daichi Imamura, Akihiko Nishio, Yoshihiko Ogawa, Shinsuke Takaoka
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Publication number: 20250089034Abstract: A scheduling apparatus and a scheduling method, wherein the amount of signaling for frequency resource allocation information can be reduced while maintaining system throughput performance. In a base station apparatus, a scheduling section allocates frequency resources to frequency allocation target terminals based on set frequency allocation units, and a frequency allocation parameter setting section adjusts the set frequency allocation units set in the scheduling section based on cluster numbers. Due to this, in each cluster number, frequency resources can be allocated based on the most suitable frequency allocation units with respect to the signaling bit number. As a result, the amount of signaling for frequency resource allocation information can be reduced. Further, system throughput can be maintained by making the cluster number, which is a parameter having little effect on system throughput, a setting parameter for frequency allocation units.Type: ApplicationFiled: November 21, 2024Publication date: March 13, 2025Inventors: Takashi Iwai, Sadaki FUTAGI, Daichi IMAMURA, Akihiko NISHIO, Seigo NAKAO, Yoshihiko OGAWA
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Publication number: 20250070950Abstract: Provided is a radio communication device which can prevent interference between SRS and PUCCH when the PUCCH transmission bandwidth fluctuates and suppress degradation of CQI estimation accuracy by the band where no SRS is transmitted. The device includes: an SRS code generation unit (201) which generates an SRS (Sounding Reference Signal) for measuring uplink line data channel quality; an SRS arrangement unit (202) which frequency-multiplexes the SRS on the SR transmission band and arranges it; and an SRS arrangement control unit (208) which controls SRS frequency multiplex so as to be uniform in frequency without modifying the bandwidth of one SRS multiplex unit in accordance with the fluctuation of the reference signal transmission bandwidth according to the SRS arrangement information transmitted from the base station and furthermore controls the transmission interval of the frequency-multiplexed SRS.Type: ApplicationFiled: November 12, 2024Publication date: February 27, 2025Inventors: Atsushi MATSUMOTO, Daichi IMAMURA, Takashi IWAI, Yoshihiko OGAWA, Tomofumi TAKATA, Katsuhiko HIRAMATSU
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Publication number: 20250071774Abstract: Disclosed is a base station in which the frequency usage efficiency can be improved when the communication bandwidths are asymmetric in the uplink line and the downlink line. A base station can communicate by using a plurality of downlink unit bands and a smaller number of uplink unit bands. A control unit allocates uplink resource allocation information and downlink resource allocation information to a PDCCH which is arranged in each of the plurality of downlink unit bands, and allocates a response signal to the uplink line data to a PHICH which is arranged in the same number of downlink unit bands from the plurality of downlink unit bands as there are uplink unit bands. A transmit RF unit transmits the resource allocation information or the response signal.Type: ApplicationFiled: November 12, 2024Publication date: February 27, 2025Inventors: Seigo Nakao, Akihiko Nishio, Daichi Imamura
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Patent number: 12238038Abstract: A wireless communication base station apparatus which is able to prevent deterioration in the throughput of LTE terminals even when LTE terminals and LTE+ terminals coexist. In this apparatus, based on the mapping pattern of the reference signals used only in LTE+ terminals, a setting unit sets, in each subframe, the resource block groups where the reference signals used only by the LTE+ terminals are mapped. For symbols mapped to the antennas, an mapping unit maps, to all the resource blocks within one frame, cell specific reference signals used for both LTE terminals and LTE+ terminals. For the symbols mapped to the antennas, the mapping unit maps, to the plurality of resource blocks, of which part of the resource block groups is comprised, in the same subframe within one frame, the cell specific reference signals used only for LTE+ terminals, based on the setting results inputted from the setting unit.Type: GrantFiled: April 16, 2024Date of Patent: February 25, 2025Assignee: Sun Patent TrustInventors: Akihiko Nishio, Seigo Nakao, Daichi Imamura
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Patent number: 12232116Abstract: Provided are a terminal device and a retransmission control method that make it possible to minimize increases in overhead in an uplink control channel (PUCCH), even if channel selection is used as the method to transmit response signals during carrier-aggregation communication using a plurality of downlink unit bands. On the basis of the generation status of uplink data and error-detection results obtained by a CRC unit, a control unit in the provided terminal uses response signal transmission rules to control the transmission of response signals or uplink control signals that indicate the generation of uplink data. If an uplink control signal and a response signal are generated simultaneously within the same transmission time unit, the control unit changes the resources allocated to the response signal and/or the phase point of the response signal in accordance with the number and position of ACKs within the error-detection result pattern.Type: GrantFiled: December 18, 2019Date of Patent: February 18, 2025Assignee: Sun Patent TrustInventors: Seigo Nakao, Akihiko Nishio, Ayako Horiuchi, Daichi Imamura