Patents by Inventor Tetsushi Abe

Tetsushi Abe 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).

  • Patent number: 8681886
    Abstract: The communication apparatus includes: a processing unit 52 configured to determine a data modulation scheme for each stream based on first signal quality q1 for each stream determined by the MMSE method; a processing unit 54 configured to determine second signal quality q2 corresponding to the first signal quality q1; a processing unit configured to determine third signal quality q3(1) of a stream by adding first signal quality q1(1) of the stream and a correction value ?q(1) derived from second signal quality q2(2) of equal to or more than 1 stream other than the stream; and a processing unit 58 configured to determine channel coding rate Rk corresponding to third signal quality q3(1) for each stream. The determined data modulation scheme and channel coding scheme are used for transmission of a following stream.
    Type: Grant
    Filed: May 20, 2009
    Date of Patent: March 25, 2014
    Assignee: NTT DoCoMo, Inc.
    Inventors: Hidekazu Taoka, Tetsushi Abe
  • Publication number: 20140073341
    Abstract: The present invention is designated to improve received quality in a mobile terminal apparatus when coordinated multiple-point transmission (CoMP)—in particular, DCS-CoMP—is adopted. With the radio communication method of the present invention, when dynamic cell selection-type coordinated multiple-point transmission is adopted, a radio base station apparatus increases transmission power in radio resources to transmit to a mobile terminal apparatus, transmits the increased transmission power to the mobile terminal apparatus as transmission power information and performs dynamic cell selection-type coordinated multiple-point transmission at the increased transmission power.
    Type: Application
    Filed: May 10, 2012
    Publication date: March 13, 2014
    Applicant: NTT DOCOMO, INC.
    Inventors: Satoshi Nagata, Tetsushi Abe, Yoshihisa Kishiyama, Jianchi Zhu, Xiang Yun
  • Publication number: 20140064244
    Abstract: The present invention is designed to provide a base station apparatus, a mobile terminal apparatus, a communication system and a communication method that cope with the shortage of downlink control channel capacity. For a mobile terminal apparatus that receives downlink signals using a resource region for downlink control signals and a resource region for downlink data signals, a base station apparatus is configured to set a plurality of virtual to resources for downlink control signals in a plurality of physical resources that are arranged in a frequency direction in the resource region for downlink data signals, and allocate the downlink control signals, in a distributed manner, between virtual resources of a relatively low frequency band side and virtual resources of a relatively high frequency band side in a plurality of virtual resources.
    Type: Application
    Filed: February 9, 2012
    Publication date: March 6, 2014
    Applicant: NTT DOCOMO, INC.
    Inventors: Yoshihisa Kishiyama, Kazuaki Takeda, Satoshi Nagata, Tetsushi Abe
  • Publication number: 20140056247
    Abstract: To reduce interference that a user terminal connecting to a base station apparatus forming a large-scale cell undergoes from a base station apparatus forming a small-scale cell in a radio communication system in which the small-scale cell is provided in the large-scale cell, a femto-base station forming a femto-cell provided in a macro-cell receives cell identification information of a macro-base station, determines cell identification information of the femto-base station based on the received cell identification information of the macro-base station so as to reduce interference to a control format indicator channel assigned to radio resources by the macro-base station, and controls assignment of control channels to radio resources based on the determined cell identification information of the femto-base station.
    Type: Application
    Filed: February 17, 2012
    Publication date: February 27, 2014
    Applicant: NTT DOCOMO, INC.
    Inventors: Zubin Bharucha, Auer Gunther, Tetsushi Abe, Nobuhiko Miki
  • Publication number: 20140057669
    Abstract: To reduce the number of cells in which a “Measurement Subframe Pattern” is broadcasted, in the mobile communication method according to the present invention, a radio base station eNB#2 broadcasts setting broadcast information in a cell #2 when a radio base station eNB#1 broadcasts a “Measurement Subframe Pattern” in a cell #1. A MOBILE STATION UE in Idle mode receives the “Measurement Subframe Pattern” broadcasted in the cell #1 in order to perform a “Measurement process” based on the “Measurement Subframe Pattern” when the MOBILE STATION UE detects, based on the setting broadcast information broadcasted in the cell #2, that the “Measurement Subframe Pattern” is broadcasted in a neighbor cell.
    Type: Application
    Filed: April 23, 2012
    Publication date: February 27, 2014
    Applicant: NTT DOCOMO, INC.
    Inventors: Hideaki Takahashi, Tetsushi Abe, Mikio Iwamura
  • Publication number: 20140050115
    Abstract: To enable a “Measurement process” using a plurality of “Measurement Subframe Patterns”, the mobile communication method according to the present invention includes notifying the ID corresponding to a “Measurement Subframe Pattern” to a MOBILE STATION UE using an “RRC Connection Release”; receiving the ID broadcasted in a neighbor cell when the MOBILE STATION UE is in Idle mode; and performing a “Measurement process” based on a “Measurement Subframe Pattern” corresponding to the received ID when the MOBILE STATION is in Idle mode.
    Type: Application
    Filed: April 23, 2012
    Publication date: February 20, 2014
    Applicant: NTT DOCOMO, INC.
    Inventors: Hideaki Takahashi, Tetsushi Abe, Mikio Iwamura
  • Publication number: 20140045497
    Abstract: A radio base station includes: a category acquisition unit configured to acquire one or more mobile station categories indicating capability of a mobile station with which to communicate; a category determination unit configured to determine a mobile station category to be applied to radio communications with the mobile station from the mobile station categories acquired by the category acquisition unit to correspond to one of parameters to be used in rate matching processing of the mobile station; and a category notification unit configured to notify the mobile station of the mobile station category determined by the category determination unit.
    Type: Application
    Filed: March 7, 2012
    Publication date: February 13, 2014
    Applicant: NTT DOCOMO, INC.
    Inventors: Tetsushi Abe, Mikio Iwamura, Kazuaki Takeda
  • Publication number: 20140023009
    Abstract: In order to report aperiodic channel state information (A-CSI) flexibly even when a user terminal performs radio communication using a plurality of component carriers (CCs) in an HetNet environment, the present invention provides an aperiodic channel sate information reporting method comprising: a step of transmitting in advance, from a pico base station (PeNB) to pico UE, channel state measurement target information having information about presence or absence of reporting of channel state information and a subframe as a measurement target associated with trigger bit information indicating information about presence or absence of reporting of channel state information and a component carrier as a measurement target (step ST401); and a step of reporting channel state information of the subframe and the component carrier designated by the trigger bit information transmitted on a PDCCH, to the pico base station (PeNB) on a PUSCH (step ST406).
    Type: Application
    Filed: February 13, 2012
    Publication date: January 23, 2014
    Applicant: NTT DOCOMO, INC.
    Inventors: Tetsushi Abe, Kazuaki Takeda, Nobuhiko Miki
  • Publication number: 20140003271
    Abstract: The present invention is designed to transmit and receive reference signals adequately even when the abundance ratio of reference signals in a predetermined period is increased. The present invention provides a base station apparatus that transmits CSI-RSs to the first mobile terminal apparatus which can receive CSI-RSs and to a second mobile terminal apparatus which can receive CSI-RSs that are set in a predetermined period at a lower abundance ratio than the first mobile terminal apparatus, and this base station apparatus allocates CSI-RSs to CSI-RS resource which can be muted at an abundance ratio which allows the first mobile terminal apparatus reception, reports the resources where CSI-RSs are allocated to the first mobile terminal apparatus, and, upon reporting the resources where CSI-RSs are allocated to the second mobile terminal apparatus, reports part of the resources as muted resources.
    Type: Application
    Filed: December 21, 2011
    Publication date: January 2, 2014
    Applicant: NTT DOCOMO, INC.
    Inventors: Tetsushi Abe, Satoshi Nagata
  • Publication number: 20130343270
    Abstract: In order to assure reception of broadcast information by a user terminal handed over to a micro base station by CRE (Cell Range Expansion) and to reduce the number of transmission stopped subframes in a macro base station, the present invention provides a notification method for a user terminal to receive modification notification information for notifying modification in system information from the micro base station, the notification method including: the macro base station notifying the micro base station of a subframe pattern including a protection subframe to protect the modification notification information every a plurality of radio frames; and the micro base station notifying the user terminal of identification information of the protection subframe in the subframe pattern.
    Type: Application
    Filed: November 8, 2011
    Publication date: December 26, 2013
    Applicant: NTT DOCOMO, INC.
    Inventors: Tetsushi Abe, Mikio Iwamura, Hideaki Takahashi, Hiroyuki Ishii, Satoshi Nagata, Naoto Ookubo, Nobuhiko Miki, Anil Umesh
  • Publication number: 20130336270
    Abstract: To effectively improve the reception quality in a pico-base station, while preventing throughput of a macro-base station from significantly deteriorating, a macro-base station (M-BS) is provided with a beam generating section (35) that generates a directional beam to a macro-UE using antenna weights based on a beampattern assigned to the macro-UE existing in a macro-cell having a first coverage area, and a coordination section (36) that determines a beam pattern so that a beam pattern to the macro-UE existing in the macro-cell is a beam pattern that suppresses interference power to a pico-UE existing in a pico-cell, in assigning the beam pattern to the macro-UE existing in the macro-cell during a transmission period assigned to a pico-base station (P-BS) locally forming the pico-cell in the macro-cell.
    Type: Application
    Filed: January 5, 2012
    Publication date: December 19, 2013
    Applicant: NTT DOCOMO, INC.
    Inventors: Satoshi Nagata, Tetsushi Abe, Nobuhiko Miki, Yuuya Saitou
  • Publication number: 20130336149
    Abstract: A user equipment (10) according to the present invention includes an interference removing function capable of removing interference from a neighboring cell, a RSSI measuring unit (107) that, with regard to a predetermined sub-frame, is configured to measure a radio quality of the serving cell and the neighboring cell for all OFDM symbols within the predetermined sub-frame and that, with regard to sub-frames other than the predetermined sub-frame, is configured to measure the radio quality of the serving cell and the neighboring cell for OFDM symbols containing a reference signal within the sub-frames. The RSSI measuring unit (107) measures the radio quality using the interference removing function in consideration of a received power of a reference signal, a PSS/SSS, and a PBCH signal.
    Type: Application
    Filed: January 11, 2012
    Publication date: December 19, 2013
    Applicant: NTT DOCOMO, INC.
    Inventors: Hiroyuki Ishii, Daisuke Nishikawa, Tetsushi Abe
  • Publication number: 20130336150
    Abstract: The present invention makes it possible to transmit and receive CSI-RSs adequately even when the number of CSI-RSs increase following the increase of antennas. The present invention provides a base station apparatus (20) that transmits CSI-RSs to a mobile terminal apparatus (10A) which is capable of receiving CSI-RSs for channel state measurement from a plurality of antennas, and to a mobile terminal apparatus (10B) which is capable of receiving CSI-RSs from a smaller number of antennas than the mobile terminal apparatus, and this base station apparatus has a CSI-RS allocation section (211) which allocates CSI-RSs for the number of antennas which the mobile terminal apparatus (10A) supports, to radio resources, and a transmitting/receiving section which reports, to the mobile terminal apparatus (10A), the resources where the CSI-RSs are allocated, and which, upon reporting the resources where CSI-RSs are allocated, to the mobile terminal apparatus (10B), reports part of the resources as resources to be muted.
    Type: Application
    Filed: February 13, 2012
    Publication date: December 19, 2013
    Applicant: NTT DOCOMO, INC.
    Inventors: Tetsushi Abe, Satoshi Nagata, Mikio Iwamura
  • Publication number: 20130336148
    Abstract: A user equipment 10 according to the present invention is provided with a RSSI measuring unit 107 that, with regard to a predetermined sub-frame, is configured to measure a radio quality of a serving cell and a neighboring cell for all OFDM symbols within the predetermined sub-frame and that, with regard to sub-frames other than the predetermined sub-frame, is configured to measure the radio quality of the serving cell and the neighboring cell for OFDM symbols containing a reference signal within the sub-frames.
    Type: Application
    Filed: January 11, 2012
    Publication date: December 19, 2013
    Applicant: NTT DOCOMO, INC.
    Inventors: Hiroyuki Ishii, Daisuke Nishikawa, Tetsushi Abe
  • Publication number: 20130322392
    Abstract: The present invention is designed to reduce interference from a macro base station to a small transmission power node. The present invention is characterized in providing a micro base station which forms, in a macro cell where a macro base station transmits a signal to a macro terminal, a micro cell where the micro base station transmits a signal to a micro terminal under control with low power, and this micro base station generates a PDCCH which includes downlink or uplink resource allocation information, and, in a non-transmission period in which the macro base station stops transmitting signals while leaving minimal quality measurement signals, shifts the transmission starting symbol of the PDCCH to a position where the PDCCH does not overlap the quality measurement signals.
    Type: Application
    Filed: February 13, 2012
    Publication date: December 5, 2013
    Applicant: NTT DOCOMO, INC.
    Inventors: Tetsushi Abe, Satoshi Nagata, Kazuaki Takeda
  • Publication number: 20130308540
    Abstract: The present invention is designated to reduce the deterioration of transmission characteristics upon data transmission, even when soft buffer memory for retransmission control is not sufficiently secured in a mobile terminal apparatus. The present invention provides the steps of, in a base station apparatus (eNB), performing channel coding of information bits (ST 802), performing a rate matching process for the coded bits after interleaving (ST 804), and transmitting transmission data to match the coded bit length after rate matching, to a mobile terminal apparatus (UE) (ST 806), and, in the mobile terminal apparatus (UE), receiving the transmission data (ST 807), performing channel decoding of the received data (ST 810), and discarding part of the received data in accordance with the size of the soft buffer memory in the mobile terminal apparatus (UE) and storing this in the soft buffer memory (ST 812 and ST 813).
    Type: Application
    Filed: January 5, 2012
    Publication date: November 21, 2013
    Applicant: NTT DOCOMO, INC.
    Inventors: Tetsushi Abe, Kazuaki Takeda, Naoto Ookubo, Hiroyuki Ishii, Yuta Sagae
  • Publication number: 20130308607
    Abstract: In order to transmit a paging to a user terminal with high quality, transmit a CSI-RS effectively and perform UL HARQ efficiently in HetNet, the present invention provides a radio communication method having the steps of: a micro base station which is arranged in a macro cell and forms a smaller micro cell than the macro cell, transmitting, to a user terminal, a signal having a CSI-RS subframe including a CSI-RS and a paging subframe including modification notification information indicating modification in system information and a control signal indicating not to measure a CSI-RS when the CSI-RS subframe and the paging subframe collide with each other; and the user terminal determining a CSI-RS subframe to measure the CSI-RS based on the control signal when the CSI-RS subframe and the paging subframe collide with each other.
    Type: Application
    Filed: November 8, 2011
    Publication date: November 21, 2013
    Applicant: NTT DOCOMO, INC.
    Inventors: Tetsushi Abe, Satoshi Nagata, Nobuhiko Miki, Naoto Ookubo
  • Publication number: 20130301445
    Abstract: Provided are a radio base station, a user terminal and a radio communication method capable of making accurate measurement in various network configurations in HetNet. The radio communication method according to the present invention has, in a heterogeneous network having a network configuration where a macro cell overlays a micro cell that is smaller than the macro cell, a radio base station that forms the macro cell and is connected to a macro terminal under control of the macro cell determining a measurement subframe to measure a CRS based on the network configuration, generating a time reference indicating the measurement subframe and transmitting a signal including the time reference and the CRS to the macro terminal; and the macro terminal receiving the time reference and the CRS and measuring the CRS in the measurement subframe indicated by the time reference.
    Type: Application
    Filed: November 10, 2011
    Publication date: November 14, 2013
    Applicant: NTT DOCOMO, INC.
    Inventors: Tetsushi Abe, Mikio Iwamura, Nobuniko Miki, Hideaki Takahashi
  • Publication number: 20130301528
    Abstract: Provided is a mobile communication method including a step A of transmitting, by a mobile station UE, “Measurement Report” including measurement results of radio qualities of neighboring cells #2 to #4 in a downlink to a radio base station eNB#1 that manages a cell #1 in which the mobile station UE is in communication, a step B of selecting, by the radio base station eNB#1, the cell #2 from among the neighboring cells #2 to #4 on the basis of the “Measurement Report”, and a step C of transmitting, by the radio base station eNB#1, “DL HI indication” indicating an influence of interference on the mobile station UE in a downlink direction being strong to a radio base station eNB#2 that manages the cell #2.
    Type: Application
    Filed: November 11, 2011
    Publication date: November 14, 2013
    Applicant: NTT DOCOMO, INC.
    Inventors: Hideaki Takahashi, Tetsushi Abe, Mikio Iwamura
  • Publication number: 20130301512
    Abstract: A mobile communication method according to the present invention includes a step of setting, by a radio base station eNB#10, when a subframe designated by a pattern of ABS, the pattern being notified by a radio base station eNB#1, matches a subframe set as an MBSFN subframe, the matching subframe as an MBSFN subframe used for “eICIC”.
    Type: Application
    Filed: October 20, 2011
    Publication date: November 14, 2013
    Applicant: NTT DOCOMO, INC.
    Inventors: Hideaki Takahashi, Tetsushi Abe