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: 20200245308
    Abstract: 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: Application
    Filed: April 16, 2020
    Publication date: July 30, 2020
    Inventors: Seigo Nakao, Akihiko Nishio, Daichi Imamura
  • Publication number: 20200245326
    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: April 13, 2020
    Publication date: July 30, 2020
    Inventors: Takashi IWAI, Daichi IMAMURA, Tomofumi TAKATA, Yoshihiko OGAWA
  • Patent number: 10727997
    Abstract: A Method of scrambling reference signals, device and user equipment using the method are provided. In the method, a plurality of layers of reference signals assigned on predetermined radio resource of a plurality of layers of resource blocks with the same time and frequency resources are scrambled, the method comprising: an orthogonalizing step of multiplying each layer of reference signal selectively by one of a plurality of orthogonal cover codes (OCCs) with the same length wherein the OCC multiplied to a first layer of reference signal can be configured as different from those multiplied to other layers of reference signals; and a scrambling step of multiplying all of symbols obtained from the OCC multiplied to each of the other layers of reference signals by a symbol-common scrambling sequence wherein the symbol-common scrambling sequences can be different from each other for reference signals multiplied by the same OCC.
    Type: Grant
    Filed: June 28, 2018
    Date of Patent: July 28, 2020
    Assignee: Sun Patent Trust
    Inventors: Hui Tong, Masayuki Hoshino, Ming Xu, Daichi Imamura
  • Publication number: 20200229200
    Abstract: It is possible to provide a radio communication terminal device and a radio transmission method which can improve reception performance of a CQI and a reference signal. A phase table storage unit stores a phase table which correlates the amount of cyclic shift to complex coefficients {w1, w2} to be multiplied on the reference signal. A complex coefficient multiplication unit reads out a complex coefficient corresponding to the amount of cyclic shift indicated by resource allocation information, from the phase table storage unit and multiplies the read-out complex coefficient on the reference signal so as to change the phase relationship between the reference signals in a slot.
    Type: Application
    Filed: March 31, 2020
    Publication date: July 16, 2020
    Inventors: Tomofumi Takata, Daichi Imamura, Seigo Nakao, Sadaki Futagi, Takashi Iwai, Yoshihiko Ogawa
  • Patent number: 10716132
    Abstract: A wireless communication base station device, terminal device, and method have reduced signaling while maintaining high scheduling gain. A judgment unit pre-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, and the maximum value for the number of clusters that is output by the judgment 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: August 2, 2018
    Date of Patent: July 14, 2020
    Assignee: Sun Patent Trust
    Inventors: Yoshihiko Ogawa, Akihiko Nishio, Daichi Imamura, Seigo Nakao, Masayuki Hoshino, Takashi Iwai, Sadaki Futagi
  • Patent number: 10715287
    Abstract: In a base station, a control unit and a data size regulation unit control the data size of downstream assignment control data and upstream assignment control data in the PDCCH signal based on the communication format used between the base station and a terminal, the number of base station antennas (M) (nonnegative number), the number of terminal antennas (N) (nonnegative number), the bandwidth of the downstream band, and the bandwidth of the upstream band. Specifically, the control unit determines it is unnecessary to adjust the aforementioned data size when the selected communication format is first established between multiple antennas and when where there are multiple for one of M and N and only one for the other. The quality of downstream assignment control data is prevented from degrading, while preventing the number of blind determinations from increasing on the receiving side of the downstream control channel signal.
    Type: Grant
    Filed: December 8, 2017
    Date of Patent: July 14, 2020
    Assignee: Sun Patent Trust
    Inventors: Seigo Nakao, Akihiko Nishio, Daichi Imamura
  • Patent number: 10708886
    Abstract: Provided is a radio communication terminal which is capable of measuring quality in communication with a handover destination with high accuracy. The radio communication terminal is capable of communicating with a base station or a relay node, and includes: a receiver which receives control information including information relating to measurement of measuring quality of a neighbor cell; an extractor which extracts information on a subframe where the measurement should be performed, which is a subframe where only transmission of a signal from the relay node connected to the base station is performed, from the information relating to the measurement; a measurement section which performs the measurement, on a subframe basis, based on the extracted information on the subframe where the measurement should be performed; and a transmitter which transmits a result of the measurement to the base station or the relay node.
    Type: Grant
    Filed: February 25, 2019
    Date of Patent: July 7, 2020
    Assignee: Sun Patent Trust
    Inventors: Yasuaki Yuda, Seigo Nakao, Ayako Horiuchi, Akihiko Nishio, Daichi Imamura, Kenichi Miyoshi
  • Publication number: 20200213064
    Abstract: A communication apparatus comprises a generator that generates frequency resource position information corresponding to a first information which is based on the communication quality information received from user equipments, the frequency resource position information indicating validity or invalidity of the first information for each frequency resource, and a transmitter that transmits the first information, the frequency resource position information and a cell ID which the frequency resource position is applied, to another communication apparatus via a backhaul.
    Type: Application
    Filed: March 10, 2020
    Publication date: July 2, 2020
    Inventors: Shinsuke Takaoka, Daichi Imamura, Kenichi Miyoshi
  • Publication number: 20200204231
    Abstract: The present disclosure provides a method of generating codebook in a wireless communication system with multiple antenna arrays, as well as a wireless communication system, base station and terminal using the codebook for communication. The method comprises steps of: providing a basic codebook which contains multiple pre-coding matrices; and assigning phase offsets to certain pre-coding matrices in the basic codebook to form a codebook with phase offset. The feedback overhead from a client to a base station side is reduced and a good precision of feedback for multi-antenna array is kept by applying the method of generating codebook and using the generated codebook in the wireless communication system, base station and terminal.
    Type: Application
    Filed: February 28, 2020
    Publication date: June 25, 2020
    Inventors: Hui Tong, Masayuki Hoshino, Ming Xu, Seigo Nakao, Daichi Imamura
  • Publication number: 20200205091
    Abstract: 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: Application
    Filed: March 2, 2020
    Publication date: June 25, 2020
    Inventors: Takashi Iwai, Akihiko Nishio, Daichi Imamura, Yoshihiko Ogawa, Atsushi Matsumoto
  • Patent number: 10693604
    Abstract: The invention provides a base station that does not cause the number of blind decodings to be increased and further can prevent the flexibility of resource allocation from degrading. A search space setting unit sets search spaces each of which is constituted by one or more control channel elements (CCEs) and each of which is to be decoded in the terminals and each of which is defined by a plurality of to-be-decoded candidates. An allocating unit places, in one of the plurality of to-be-decoded candidates included in the search space, a control channel. The number of connections of CCEs constituting the to-be-decoded candidate is associated with the number of to-be-decoded candidates. The search space setting unit causes, in accordance with the control channel to be transmitted, the association of the number of connections of CCEs constituting the to-be-decoded candidate with the number of to-be-decoded candidates to differ.
    Type: Grant
    Filed: June 15, 2018
    Date of Patent: June 23, 2020
    Assignee: Sun Patent Trust
    Inventors: Seigo Nakao, Akihiko Nishio, Ayako Horiuchi, Daichi Imamura
  • Publication number: 20200196292
    Abstract: Provided are a radio terminal device, a radio base station device, and a channel signal forming method which can prevent quality degradation of the downlink resource allocation information by reducing the frequency of the zero information addition process to the downlink resource allocation information when executing communication using an uplink unit band and multiple downlink unit bands correlated to the uplink unit band. A base station includes: a PDCCH generation unit which includes the uplink allocation information relating to the uplink unit band only in some of the channel signals formed for each of the downlink unit bands; and a padding unit which adds zero information to the downlink allocation information only in the selected some channel signals having the bandwidth of the corresponding downlink unit band smaller than that of the uplink unit band until the downlink allocation information size becomes equal to the uplink allocation information size.
    Type: Application
    Filed: February 27, 2020
    Publication date: June 18, 2020
    Inventors: Seigo Nakao, Akihiko Nishio, Daichi Imamura, Takahisa Aoyama
  • Patent number: 10687368
    Abstract: A sequence allocating method and apparatus wherein in a system where a plurality of different Zadoff-Chu sequences or GCL sequences are allocated to a single cell, the arithmetic amount and circuit scale of a correlating circuit at a receiving end can be reduced. In ST201, a counter (a) and a number (p) of current sequence allocations are initialized, and in ST202, it is determined whether the number (p) of current sequence allocations is coincident with a number (K) of allocations to one cell. In ST203, it is determined whether the number (K) of allocations to the one cell is odd or even. If K is even, in ST204-ST206, sequence numbers (r=a and r=N?a), which are not currently allocated, are combined and then allocated. If K is odd, in ST207-ST212, for sequences that cannot be paired, one of sequence numbers (r=a and r=N?a), which are not currently allocated, is allocated.
    Type: Grant
    Filed: May 23, 2019
    Date of Patent: June 16, 2020
    Assignee: Panasonic Corporation
    Inventors: Daichi Imamura, Takashi Iwai, Kazunori Inogai, Sadaki Futagi, Atsushi Matsumoto
  • Patent number: 10686550
    Abstract: A radio transmitting device and method enables reduction of an increase of CGI memories for the control channel and an improvement of the throughput of the data channel. When multiplex transmission through the control channel and the data channel is carried out and when adaptive modulation is applied to both channels, an MCS selecting section is provided with one CQI table for the data channel and CQI tables for the control channel, and a table selecting MCS determining section selects one of the tables depending on the transmission bandwidth of the terminal and determines the MCS of the control channel while looking up the selected CQI table.
    Type: Grant
    Filed: January 22, 2019
    Date of Patent: June 16, 2020
    Assignee: Godo Kaisha IP Bridge 1
    Inventors: Sadaki Futagi, Daichi Imamura, Seigo Nakao, Tomofumi Takata
  • Patent number: 10681650
    Abstract: A base station includes a transmitter which transmits an offset value for a transmission power of a sounding reference signal (SRS) to a terminal apparatus; and a receiver which receives the SRS at the transmission power controlled by the terminal apparatus. The offset value used to control the transmission power is set within one of a first offset setting range having a first lower limit value and a first upper limit value and a second offset setting range having a second lower limit value and a second upper limit value. A difference between the first and second lower limit values equals a difference between the first and second upper limit values. A step width of the offset values within the first offset setting range equals a step width of the offset values within the second offset setting range. The SRS is a periodic SRS (P-SRS) or an aperiodic SRS (A-SRS).
    Type: Grant
    Filed: November 27, 2018
    Date of Patent: June 9, 2020
    Assignee: Sun Patent Trust
    Inventors: Takashi Iwai, Daichi Imamura, Masayuki Hoshino, Akihiko Nishio, Takashi Tamura, Kazuki Takeda
  • Patent number: 10681635
    Abstract: The transmission of a reference signal, such as a CSI-RS, is enabled while maintaining a power saving effect when performing inter-cell cooperative transmission/reception or the like in a plurality of cells. In order to realize inter-cell cooperative transmission/reception, a CSI-RS which is used for estimating the state of a spatial propagation path of a communication line is generated by a CSI-RS generation unit, and the CSI-RS is disposed in a predetermined subframe by a disposition unit and transmitted. At this time, when a frame has ten subframes #0 to #9, the CSI-RS is disposed in the subframes #4 and #9, which are subframes excluding the subframes #0 and #5 incapable of transmitting a CSI-RS and are subframes other than subframes capable of acting as MBSFN subframes when discontinuous communication (Extended Cell DTX) is performed so as to achieve power saving, and transmitted.
    Type: Grant
    Filed: April 18, 2019
    Date of Patent: June 9, 2020
    Assignee: SUN PATENT TRUST
    Inventors: Atsushi Sumasu, Daichi Imamura, Ayako Horiuchi, Yasuaki Yuda
  • Publication number: 20200178219
    Abstract: To suppress concentration of channel quality information requests and reports in a case of discontinuously transmitting reference signals at specific resources in a time domain, and thereby preventing degradation in throughput. A transmission apparatus transmits an instruction of CSI request distributed for each reception apparatus in a subframe concurrently with or earlier than a reference signal CSI-RS to each of reception apparatuses. Each of the reception apparatuses detects the CSI request from the transmission apparatus and calculates CSI from a channel estimation value of CSI-RS received thereafter. Then, the reception apparatus identifies CSI report subframe of the own apparatus from CSI report interval information of a given time interval notified in advance, the subframe in which the CSI request is detected and transmission timing of CSI-RS, and transmits a feedback signal including CSI report value by using PUSCH at the timing of the CSI report subframe.
    Type: Application
    Filed: February 7, 2020
    Publication date: June 4, 2020
    Inventors: Masayuki HOSHINO, Akihiko NISHIO, Seigo NAKAO, Daichi IMAMURA, Yasuaki YUDA
  • Publication number: 20200178156
    Abstract: A terminal and a communication method thereof whereby, even in a case of employing an asymmetric carrier aggregation system and further employing a MIMO transmission method for upstream channels, the error characteristic of control information can be prevented from being degraded. In the terminal, a transport signal forming unit forms transport signals by arranging, based on an arrangement rule, ACK/NACK and CQI in a plurality of layers. According to the arrangement rule, an error detection result is arranged, on a priority basis, in a layer that is different from a layer in which the channel quality information is arranged. In this way, the puncturing of CQI using ACK/NACK can be minimized, with the result that the error characteristic of control information can be prevented from being degraded.
    Type: Application
    Filed: February 10, 2020
    Publication date: June 4, 2020
    Inventors: Yoshihiko OGAWA, Seigo NAKAO, Akihiko NISHIO, Masayuki HOSHINO, Daichi IMAMURA, Atsushi SUMASU
  • Publication number: 20200177332
    Abstract: A data alignment method capable of preventing degradation in demodulation performance due to variation in signal qualities when a data signal to which a Turbo code is applied is transmitted simultaneously from a plurality of cells. The method divides signal components to be used for data alignment into resources common to all the cells and resources dependent on the cells and transmits encoded and rate-matched data with the first half thereof aligned to the resources common to all the cells and the second half thereof aligned to the resources dependent on the cells.
    Type: Application
    Filed: December 10, 2019
    Publication date: June 4, 2020
    Inventors: Masayuki HOSHINO, Seigo NAKAO, Daichi IMAMURA
  • Patent number: 10674493
    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: Grant
    Filed: May 6, 2019
    Date of Patent: June 2, 2020
    Assignee: Sun Patent Trust
    Inventors: Akihiko Nishio, Daichi Imamura