Patents by Inventor Naoto Okubo
Naoto Okubo 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: 20120190393Abstract: A radio base station eNB according to the present invention includes: a PRS transmission unit 12 configured to transmit PRS in subordinate cells #1 to #3; and a PDCCH signal transmission unit 10 configured to, when transmitting the PRS in the cells #1 to #3, generate and transmit a PDCCH signal by using PRS-RNTI.Type: ApplicationFiled: August 27, 2010Publication date: July 26, 2012Applicant: NTT DOCOMO, INC.Inventors: Minami Ishii, Sadayuki Abeta, Naoto Okubo, Mikio Iwamura
-
Publication number: 20120182951Abstract: A radio base station eNB according to the present invention includes: a synchronization signal transmission unit 10 configured to transmit a synchronization signal including a cell ID assigned to a subordinate cell #1; a broadcast information transmission unit 11 configured to transmit broadcast information including a virtual cell ID assigned to the cell #1; and an RS transmission unit 14 configured to transmit CRS (first reference signal) determined uniquely by the cell ID and transmit PRS (second reference signal) determined uniquely by the virtual cell ID, wherein a range of values assignable as the virtual cell ID is configured to be larger than a range of values assignable as the cell ID.Type: ApplicationFiled: August 13, 2010Publication date: July 19, 2012Applicant: NTT DOCOMO, INC.Inventors: Naoto Okubo, Sadayuki Abeta
-
Publication number: 20120120917Abstract: A radio base station according to the present invention comprising a simulator device, including a downlink signal output unit configured to transmit a downlink signal for a first cell and transmit a downlink signal for a second cell, in the form of a simulation signal, to a mobile station, in which the downlink signal output unit is configured to shift the lead position of a radio frame from which to transmit the downlink signal for a first cell, and the lead position of a radio frame from which to transmit the downlink signal for a second cell.Type: ApplicationFiled: May 14, 2010Publication date: May 17, 2012Applicant: NTT DOCOMO, INC.Inventors: Tetsuto Shimomura, Naoto Okubo, Hiroyuki Ishii
-
Publication number: 20120106480Abstract: A radio base station according to the present invention comprising: a simulator device including a downlink signal output unit configured to transmit a downlink signal for a first cell, and a downlink signal for a second cell, in the form of a simulation signal, to a mobile station, in which the downlink signal output unit is configured to shift a lead position of a radio frame from which to transmit the downlink signal for a first cell and a lead position of a radio frame from which to transmit the downlink signal for a second cell.Type: ApplicationFiled: May 14, 2010Publication date: May 3, 2012Applicant: NTT DOCOMO, INC.Inventors: Tetsuto Shimomura, Naoto Okubo, Hiroyuki Ishii
-
Publication number: 20120093123Abstract: A radio base station includes a resource assignment unit configured to determine a time direction resource, a frequency direction resource, and a code direction resource which are to be assigned as a scheduling request transmission resource for transmitting a scheduling request that requests scheduling for uplink data communication to each mobile station. The resource assignment unit is configured to determine the time direction resource and the frequency direction resource, which are to be assigned as the scheduling request transmission resource, and then determine the code direction resource to be assigned as the scheduling request transmission resource. The resource assignment unit is configured to assign, as the scheduling request transmission resource, in order from a frequency direction resource having a lower usage rate of the code direction resource in each time direction resource.Type: ApplicationFiled: March 24, 2010Publication date: April 19, 2012Applicant: NTT DOCOMO, INC.Inventors: Kohei Kiyoshima, Hiroyuki Ishii, Naoto Okubo
-
Publication number: 20120087324Abstract: A radio base station according to the present invention comprising: a radio base station configured to transmit a transmission power control command for a mobile station for controlling transmission power of an uplink data signal of the mobile station via a downlink control channel for a transmission power control command mapped to a specific subframe in a downlink channel, the radio base station including a resource assignment unit configured to decide the specific subframe and a transmission unit configured to transmit the transmission power control command for the mobile station via the downlink control channel for the transmission power control command mapped to the specific subframe decided by the resource assignment unit, in which the resource assignment unit is configured to decide the specific subframe according to a number of transmission power control commands transmitted in each subframe.Type: ApplicationFiled: May 18, 2010Publication date: April 12, 2012Applicant: NTT DOCOMO, INC.Inventors: Kohei Kiyoshima, Hiroyuki Ishii, Naoto Okubo
-
Publication number: 20120063412Abstract: A radio base station including a resource assignment unit configured to assign a time direction resource, a frequency direction resource, and a code direction resource, as a physical signal transmission resource for transmitting a predetermined physical signal, to each mobile station is disclosed. The frequency direction resource is specified by a frequency position within a frequency region when frequency bandwidths used in a plurality of physical signals transmitted by each mobile station are the same.Type: ApplicationFiled: March 24, 2010Publication date: March 15, 2012Applicant: NTT DOCOMO, INC.Inventors: Kohei Kiyoshima, Hiroyuki Ishii, Naoto Okubo
-
Publication number: 20120063399Abstract: A radio base station includes a resource assignment unit for assigning a resource candidate for transmitting a semi-persistent scheduling transmission acknowledgement signal to a first mobile station during a semi-persistent scheduling bearer setting process. The resource candidate for transmitting a semi-persistent scheduling transmission acknowledgement signal is formed by a combination of a frequency direction resource and a code direction resource by which the first mobile station transmits a transmission acknowledgement signal after a predetermined timing from a timing of receiving downlink data, to the downlink data that has been scheduled by semi-persistent scheduling and has been transmitted via a downlink data channel.Type: ApplicationFiled: March 24, 2010Publication date: March 15, 2012Applicant: NTT DOCOMO, INC.Inventors: Kohei Kiyoshima, Hiroyuki Ishii, Naoto Okubo
-
Publication number: 20120057563Abstract: A radio base station including a resource assignment unit configured to determine a time direction resource, a frequency direction resource, and a code direction resource which are to be assigned as a reception quality notification resource that should be used for notifying each mobile station of a reception quality in a downlink, the resource assignment unit is configured to determine the time direction resources and the frequency direction resources, which are to be assigned as the reception quality notification resource, and then determine the code direction resources to be assigned as the reception quality notification resource the resource assignment unit is configured to assign, as the reception quality notification resource, in order from a frequency direction resource with a lower usage rate of the code direction resource, within each time direction resource.Type: ApplicationFiled: March 24, 2010Publication date: March 8, 2012Applicant: NTT DOCOMO, INC.Inventors: Kohei Kiyoshima, Naoto Okubo, Hiroyuki Ishii
-
Publication number: 20120039286Abstract: A base station according to the present invention includes: a PUSCH resource assignment unit (11A) configured to assign a PUSCH resource to a PUSCH of a mobile station (UE); a PHICH resource assignment unit (11B) configured to assign a first frequency direction resource and a first code direction resource to a PHICH, based on identification information of the PUSCH resource; and a notification unit (12) configured to notify, to the mobile station (UE), the PUSCH resource. When a usage situation of a code direction resource in the first frequency direction resource satisfies predetermined conditions, the PHICH resource assignment unit (11B) is configured to change a frequency direction resource and a code direction resource assigned to the PHICH from the first frequency direction resource and the first code direction resource to a second frequency direction resource and a second code direction resource.Type: ApplicationFiled: March 3, 2010Publication date: February 16, 2012Applicant: NTT DOCOMO, INC.Inventors: Naoto Okubo, Hiroyuki Ishii
-
Publication number: 20120028641Abstract: A mobile station according to the present invention includes: a dedicated signaling reception unit (12) configured to receive a dedicated signaling including a priority for a frequency or a group of frequencies of each radio access network; and a camp-on processing unit (13) configured to select a camp-on cell based on the priority or a radio quality in each cell, wherein when a predetermined flag is set to the dedicated signaling received by the dedicated signaling reception unit (12), the camp-on processing unit (13) is configured to select the camp-on cell based on the radio quality in each cell, from a plurality of cells that use a different frequency but reside within an identical radio access network, and to select the camp-on cell based on the priority included in the dedicated signaling, from a plurality of cells within a different radio access network.Type: ApplicationFiled: February 8, 2010Publication date: February 2, 2012Applicant: NTT DOCOMO, INC.Inventors: Mikio Iwamura, Hiroyuki Ishii, Kenichiro Aoyagi, Hiroaki Yamagishi, Naoto Okubo
-
Publication number: 20120026952Abstract: A mobile communication method according to the present invention, includes the steps of: (A) assigning a radio resource for a PRACH in each cell within a mobile communication system in which cells are synchronized; and (B) performing, at a mobile station (UE), a random access procedure by transmitting an RA preamble via the PRACH using the radio resource assigned in each cell, wherein in the step (A), as the radio resource for a PRACH, a resource block in a different sub-frame is assigned between adjacent cells.Type: ApplicationFiled: February 1, 2010Publication date: February 2, 2012Applicant: NTT DOCOMO, INC.Inventors: Naoto Okubo, Hiroyuki Ishii
-
Publication number: 20120026960Abstract: A radio base station (eNB) is a radio base station that can simultaneously transmit a first downlink signal in which a transmission stream number is adaptively changed, and a second downlink signal in which a transmission stream number is fixed to 1, to a mobile station using an MIMO scheme, the radio base station including: a reception quality reception unit configured to receive information indicating reception quality of the first downlink signal transmitted by the mobile station; a reception quality adjustment unit configured to calculate an adjustment value of the information indicating the reception quality based on a stream number of the first downlink signal; and a processing unit configured to perform an adaptive modulation and demodulation process and a transmission power control process on the second downlink signal based on the calculated adjustment value.Type: ApplicationFiled: March 3, 2010Publication date: February 2, 2012Applicant: NTT DOCOMO, INC.Inventors: Naoto Okubo, Hiroyuki Ishii, Yoshihisa Kishiyama
-
Publication number: 20120002616Abstract: A base station apparatus determines which mode of a subframe bundling mode (second mode) and a non-bundling mode (first mode) should be used by a user apparatus for communication, and reports a determination result. In the first mode, RTT period is a first period, and each of transmission and retransmission of the signal is performed every 1 TTI. In the second mode, RTT period is a second period that is longer than the first period, and each of transmission and retransmission of the signal is performed every plurality of TTIs. A radio resource to be used for retransmission is determined according to a first frequency hopping pattern in the first mode, and is determined according to a second frequency hopping pattern that is different from the first frequency hopping pattern in the second mode.Type: ApplicationFiled: January 29, 2010Publication date: January 5, 2012Applicant: NTT DOCOMO, INC.Inventors: Hiroyuki Ishii, Kohei Kiyoshima, Naoto Okubo
-
Publication number: 20120002577Abstract: A radio base station includes a power estimate unit configured to estimate a transmission power of an uplink signal in a mobile station (UE), a transmission format determination unit configured to determine a transmission bandwidth and a transmission frequency of the uplink signal as a transmission format of the uplink signal transmitted by the mobile station (UE), and a transmission instruction unit configured to instruct the mobile station (UE) to transmit the uplink signal by using the determined transmission format. The transmission format determination unit is configured to determine the transmission bandwidth of the uplink signal based on an estimation value of the transmission power, and to determine the transmission frequency of the uplink signal based on information relating to a cell with which the mobile station communicates.Type: ApplicationFiled: February 4, 2010Publication date: January 5, 2012Applicant: NTT DOCOMO, INC.Inventors: Hiroyuki Ishii, Naoto Okubo
-
Publication number: 20110317745Abstract: In a mobile communication system according to the present invention, a reference signal sequence includes a plurality of signal sequences assigned in slot units in the predetermined physical channel based on a hopping pattern and a sequence shift pattern; the hopping pattern is configured to be determined based on a slot number and an SFN in the predetermined physical channel or the predetermined physical signal; the sequence shift pattern is configured to be determined based on the identification information of the cell to which the predetermined physical channel or the predetermined physical signal has been set; and the hopping cycle is configured to be determined based on a cycle of the slot number and an SFN cycle.Type: ApplicationFiled: December 24, 2009Publication date: December 29, 2011Applicant: NTT DOCOMO, INC.Inventors: Naoto Okubo, Hiroyuki Ishii, Sadayuki Abeta, Yoshihisa Kishiyama
-
Publication number: 20110310817Abstract: A radio base station (eNB) according to the present invention includes an aggregation level determination unit configured to determine an aggregation level based on CQI notified from a mobile station (UE), a control channel element assignment unit configured to assign a plurality of continuous CCE to a PDCCH addressed to the mobile station (UE), based on the determined aggregation level, and a resource assignment unit configured to assign resource element groups constituting the assigned CCE as a resource for the PDCCH addressed to the mobile station (UE). The control channel element assignment unit is configured to assign a plurality of continuous CCE to the PDCCH addressed to the mobile station (UE) based on an aggregation level changed by the aggregation level determination unit, when failing to assign CCE to the PDCCH addressed to the mobile station (UE).Type: ApplicationFiled: November 6, 2009Publication date: December 22, 2011Applicant: NTT DOCOMO, INC.Inventors: Naoto Okubo, Hiroyuki Ishii
-
Publication number: 20110305152Abstract: A radio base station (eNB) includes: a calculation unit (12) configured to calculate an adjusted value of reception quality information, based on an average value of the reception quality information in the at least one first resource block assigned to a mobile station (UE) in a PDSCH, and the number of resource elements assigned within the first resource blocks as one of a radio resource for a downlink common channel and a radio resource for a PDCCH; and a selection unit (13) configured to select, based on the adjusted value of the reception quality information, a modulation scheme that should be used in the PDSCH and the number of bits that can be transmitted in each of the first resource block.Type: ApplicationFiled: December 18, 2009Publication date: December 15, 2011Applicant: NTT DOCOMO, INC.Inventors: Yoshiaki Ofuji, Hiroyuki Ishii, Naoto Okubo
-
Publication number: 20110299466Abstract: A radio base station (eNB) according to the present invention includes: an RI acquisition unit (11) configured to acquire, from a mobile station (UE), an “RI” indicating number of streams determined by the mobile station (UE); an adjustment unit (12) configured to adjust the “RI” acquired by the RI acquisition unit (11), by using an offset value “RI offset” unique to the mobile station (UE); and a stream-number determination unit (13) configured to determine the number of streams to be simultaneously transmitted to the mobile station (UE), based on the “RI” adjusted by the adjustment unit (12).Type: ApplicationFiled: December 15, 2009Publication date: December 8, 2011Applicant: NTT DOCOMO, INC.Inventors: Yoshiaki Ofuji, Naoto Okubo
-
Publication number: 20110294439Abstract: A radio base station (eNB) according to the present invention includes: a calculation unit (12) configured to calculate an adjusted value of a reception quality, based on the reception quality in a specific mobile station in at least one first resource block assigned to the specific mobile station in a PUSCH, and the number of resource elements assigned to transmission of dedicated control information in the first resource blocks; and a selection unit (13) configured to select, based on the adjusted value of the reception quality, the number of bits which can be transmitted and a modulation scheme that should be used in the first resource blocks.Type: ApplicationFiled: December 18, 2009Publication date: December 1, 2011Applicant: NTT DOCOMO, INC.Inventors: Yoshiaki Ofuji, Hiroyuki Ishii, Naoto Okubo