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).

  • Publication number: 20220271875
    Abstract: Provided is a radio communication device which can make Acknowledgement (ACK) reception quality and Negative Acknowledgement (NACK) reception quality to be equal to each other. The device includes: a scrambling unit (214) which multiplies a response signal after modulated, by a scrambling code “1” or “e?j(?/2)”, so as to rotate a constellation for each of response signals on a cyclic shift axis; a spread unit (215) which performs a primary spread of the response signal by using a Zero Auto Correlation (ZAC) sequence set by a control unit (209); and a spread unit (218) which performs a secondary spread of the response signal after subjected to the primary spread, by using a block-wise spread code sequence set by the control unit (209).
    Type: Application
    Filed: May 10, 2022
    Publication date: August 25, 2022
    Inventors: Seigo NAKAO, Daichi IMAMURA
  • Publication number: 20220255655
    Abstract: 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: Application
    Filed: April 26, 2022
    Publication date: August 11, 2022
    Inventors: Takashi Iwai, Daichi Imamura, Akihiko Nishio, Yoshihiko Ogawa, Masaru Fukuoka
  • Publication number: 20220256476
    Abstract: 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: Application
    Filed: April 27, 2022
    Publication date: August 11, 2022
    Inventors: Takashi Iwai, Daichi Imamura, Akihiko Nishio, Yoshihiko Ogawa, Shinsuke Takaoka
  • Publication number: 20220255709
    Abstract: 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: Application
    Filed: April 25, 2022
    Publication date: August 11, 2022
    Inventors: Atsushi MATSUMOTO, Daichi IMAMURA, Takashi IWAI, Yoshihiko OGAWA, Tomofumi TAKATA, Katsuhiko HIRAMATSU
  • Publication number: 20220240230
    Abstract: A communication apparatus has a receiver and a decoder. The receiver receives a control signal including first downlink control information and second downlink control information, and receives decoding area information that indicates whether the extended Physical Downlink Control Channel (PDCCH) should be decoded for each of a plurality of terminal apparatuses. The decoder decodes each of a plurality of first mapping candidates in the PDCCH area or decodes each of the plurality of first mapping candidates in the PDCCH area and each of the plurality of second mapping candidates in the extended PDCCH. A number of the second mapping candidates included in the user-specific search space equals to or is more than a number of the first mapping candidates included in the common search space.
    Type: Application
    Filed: April 11, 2022
    Publication date: July 28, 2022
    Inventors: Yoshiko SAITO, Ayako HORIUCHI, Seigo NAKAO, Akihiko NISHIO, Daichi IMAMURA, Alexander GOLITSCHEK EDLER VON ELBWART, Sujuan FENG
  • Publication number: 20220240298
    Abstract: Communication apparatuses and methods reduce the amount of signaling while maintaining a high scheduling gain. A determination unit stores a correspondence between the number of code words and the number of clusters to reduce the maximum value for the number of clusters allocated to each terminal as the number of code words increases, and thus determines the maximum value for the number of clusters based on the number of code words acquired. Based on the number of code words for a transmission signal from a terminal, an estimated value for the reception quality that is output by an estimation unit, and the maximum value for the number of clusters that is output by the determination unit, a scheduling unit schedules the allocation of the transmission signal transmitted by each terminal to a transmission band frequency (frequency resource) so as not to exceed the maximum value for the number of clusters.
    Type: Application
    Filed: April 11, 2022
    Publication date: July 28, 2022
    Inventors: Yoshihiko OGAWA, Akihiko NISHIO, Daichi IMAMURA, Seigo NAKAO, Masayuki HOSHINO, Takashi IWAI, Sadaki FUTAGI
  • Patent number: 11398891
    Abstract: 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: Grant
    Filed: February 5, 2021
    Date of Patent: July 26, 2022
    Assignee: Sun Patent Trust
    Inventors: Akihiko Nishio, Seigo Nakao, Daichi Imamura
  • Patent number: 11394507
    Abstract: 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: Grant
    Filed: December 22, 2020
    Date of Patent: July 19, 2022
    Assignee: Sun Patent Trust
    Inventors: Takashi Iwai, Sadaki Futagi, Tomohumi Takata, Daichi Imamura, Yoshihiko Ogawa
  • Patent number: 11395295
    Abstract: 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: Grant
    Filed: April 20, 2020
    Date of Patent: July 19, 2022
    Assignee: Sun Patent Trust
    Inventors: Yoshihiko Ogawa, Seigo Nakao, Daichi Imamura, Akihiko Nishio, Masayuki Hoshino, Katsuhiko Hiramatsu, Kenichi Miyoshi, Yasuaki Yuda, Sadaki Futagi, Takashi Iwai
  • Patent number: 11387862
    Abstract: A wireless communication terminal apparatus wherein CoMP communication can normally be performed without increasing the overhead of an upstream line control channel. In this apparatus, a spreading unit (214) primarily spreads a response signal by use of a ZAC sequence established by a control unit (209). A spreading unit (217) secondarily spreads the response signal, to which CP has been added, by use of a block-wise spread code sequence established by the control unit (209). The control unit (209) controls, in accordance with sequence numbers and a hopping pattern established therein, the circular shift amount of the ZAC sequence to be used for the primary spread in the spreading unit (214) and the block-wise spread code sequence to be used for the secondary spread in the spreading unit (217). The hopping pattern established in the control unit (209) is a hopping pattern common to a plurality of base stations that CoMP-receive the response signal.
    Type: Grant
    Filed: February 19, 2021
    Date of Patent: July 12, 2022
    Assignee: Sun Patent Trust
    Inventors: Seigo Nakao, Hidetoshi Suzuki, Daichi Imamura
  • Patent number: 11388744
    Abstract: A base station able to maintain backward compatibility with an LTE mobile station while minimizing the amount of increase in uplink scheduling information reception and demodulation/decoding processing in independent uplink/downlink cell data transmission. A wireless communication system includes a cell #1, a cell #2, and an LTE-A mobile station, and supports independent uplink/downlink cell data transmission. The base station of the cell #2 arranges a PDCCH+, which includes uplink scheduling information from the LTE-A mobile station to the base station of the cell #2, in a downlink data region in the downlink connection of the base station of the cell #1.
    Type: Grant
    Filed: August 24, 2020
    Date of Patent: July 12, 2022
    Assignee: SUN PATENT TRUST
    Inventors: Atsushi Sumasu, Shozo Okasaka, Shinsuke Takaoka, Seigo Nakao, Daichi Imamura
  • Publication number: 20220191860
    Abstract: Provided are a communication device and an SRS transmission method capable of reducing the possibility of a difference in recognition between the presence or absence of an SRS transmission between a base station and a terminal or of an SRS resource so as to prevent degradation of system throughput. At a terminal (200), a reception processing unit (203) detects control information indicating whether or not to request transmission of a sounding reference signal (SRS), whereupon a transmission signal forming unit (207) transmits an A-SRS by way of control by a transmission control unit (206) on the basis of control information. The transmission control unit (206) determines whether or not to execute SRS transmission on the basis of an “SRS Transmission Execution Rule” and the reception status of trigger information.
    Type: Application
    Filed: March 4, 2022
    Publication date: June 16, 2022
    Inventors: Akihiko Nishio, Daichi Imamura
  • Patent number: 11362772
    Abstract: Provided is a radio communication device which can make Acknowledgement (ACK) reception quality and Negative Acknowledgement (NACK) reception quality to be equal to each other. The device includes: a scrambling unit (214) which multiplies a response signal after modulated, by a scrambling code “1” or “e?j(?/2)” so as to rotate a constellation for each of response signals on a cyclic shift axis; a spread unit (215) which performs a primary spread of the response signal by using a Zero Auto Correlation (ZAC) sequence set by a control unit (209); and a spread unit (218) which performs a secondary spread of the response signal after subjected to the primary spread, by using a block-wise spread code sequence set by the control unit (209).
    Type: Grant
    Filed: May 10, 2021
    Date of Patent: June 14, 2022
    Assignee: Panasonic Holdings Corporation
    Inventors: Seigo Nakao, Daichi Imamura
  • Patent number: 11356958
    Abstract: 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: Grant
    Filed: November 17, 2020
    Date of Patent: June 7, 2022
    Assignee: Sun Patent Trust
    Inventors: Takashi Iwai, Daichi Imamura, Akihiko Nishio, Yoshihiko Ogawa, Shinsuke Takaoka
  • Patent number: 11349588
    Abstract: 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: Grant
    Filed: September 30, 2020
    Date of Patent: May 31, 2022
    Assignee: SUN PATENT TRUST
    Inventors: Takashi Iwai, Daichi Imamura, Akihiko Nishio, Yoshihiko Ogawa, Masaru Fukuoka
  • Patent number: 11343051
    Abstract: 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: Grant
    Filed: September 28, 2020
    Date of Patent: May 24, 2022
    Assignee: Panasonic Holdings Corporation
    Inventors: Atsushi Matsumoto, Daichi Imamura, Takashi Iwai, Yoshihiko Ogawa, Tomofumi Takata, Katsuhiko Hiramatsu
  • Patent number: 11337196
    Abstract: A communication apparatus has a receiver and a decoder. The receiver receives a control signal including first downlink control information and second downlink control information, and receives decoding area information that indicates whether the extended Physical Downlink Control Channel (PDCCH) should be decoded for each of a plurality of terminal apparatuses. The decoder decodes each of a plurality of first mapping candidates in the PDCCH area or decodes each of the plurality of first mapping candidates in the PDCCH area and each of the plurality of second mapping candidates in the extended PDCCH. A number of the second mapping candidates included in the user-specific search space equals to or is more than a number of the first mapping candidates included in the common search space.
    Type: Grant
    Filed: September 17, 2018
    Date of Patent: May 17, 2022
    Assignee: SUN PATENT TRUST
    Inventors: Yoshiko Saito, Ayako Horiuchi, Seigo Nakao, Akihiko Nishio, Daichi Imamura, Alexander Golitschek Edler Von Elbwart, Sujuan Feng
  • Patent number: 11330618
    Abstract: Communication apparatuses and methods reduce the amount of signaling while maintaining a high scheduling gain. A determination unit stores a correspondence between the number of code words and the number of clusters to reduce the maximum value for the number of clusters allocated to each terminal as the number of code words increases, and thus determines the maximum value for the number of clusters based on the number of code words acquired. Based on the number of code words for a transmission signal from a terminal, an estimated value for the reception quality that is output by an estimation unit, and the maximum value for the number of clusters that is output by the determination unit, a scheduling unit schedules the allocation of the transmission signal transmitted by each terminal to a transmission band frequency (frequency resource) so as not to exceed the maximum value for the number of clusters.
    Type: Grant
    Filed: June 9, 2020
    Date of Patent: May 10, 2022
    Assignee: Sun Patent Trust
    Inventors: Yoshihiko Ogawa, Akihiko Nishio, Daichi Imamura, Seigo Nakao, Masayuki Hoshino, Takashi Iwai, Sadaki Futagi
  • Publication number: 20220132500
    Abstract: It is an object to provide a sequence allocating method that, while maintaining the number of Zadoff-Chu sequences to compose a sequence group, is configured to make it possible to reduce correlations between different sequential groups. This method comprises the steps of setting a standard sequence with a standard sequence length and a standard sequence number in a step, setting a threshold value in accordance with an RB number in a step, setting a sequence length corresponding to RB number in a step, judging whether ¦r/N?rb/Nb¦=Xth(m) is satisfied in a step, including a plurality of Zadoff-Chu sequences with a sequence number and a sequence length in a sequence group in a step if the judgment is positive, and allocating the sequence group to the same cell in a step.
    Type: Application
    Filed: January 7, 2022
    Publication date: April 28, 2022
    Inventors: Takashi IWAI, Daichi IMAMURA, Tomofumi TAKATA, Yoshihiko OGAWA
  • Patent number: 11310789
    Abstract: In a terminal, a control unit transmits a bundle response signal using a resource in a basic region of an uplink control channel in an uplink unit band of a unit band group when no error is detected in each of a plurality of pieces of downlink data of the unit band group, the uplink control channel in the uplink unit band being associated with a downlink control channel in a basic unit band that is a downlink unit band in which a broadcast channel signal including information relating to the uplink unit band is transmitted, and the control unit transmits the bundle response signal using a resource in an additional region of the uplink control channel when an error is detected in each of the plurality of pieces of downlink data.
    Type: Grant
    Filed: September 30, 2020
    Date of Patent: April 19, 2022
    Assignee: Godo Kaisha IP Bridge 1
    Inventors: Seigo Nakao, Daichi Imamura