Ntt Docomo, Inc.

Agency for Science, Technology and Research

Daisuke Nishikawa

Yoshihisa Kishiyama

Kazuaki Takeda

Tetsushi Abe

Hiroyuki Ishii

Teruo Kawamura

Yuta Sagae

Satoshi Nagata

Mamoru Sawahashi

Tooru Uchino

Kenichi Higuchi

Nobuhiko Miki

Hideaki Takahashi

Anil Umesh

Sadayuki Abeta

Motohiro Tanno

Zhongding Lei

Francois Po Shin Chin

Sai Ho Wong

One aspect of the present invention relates to a mobile station having a SAR backoff function including a SAR signaling receiving unit configured to receive a SAR signaling from a base station, the SAR signaling indicating that a SAR backoff is available, and a maximum transmit power determination unit configured to determine maximum transmit power of the mobile station depending on whether the SAR signaling receiving unit has received the SAR signaling, wherein in response to receiving the SAR signaling at the SAR signaling receiving unit, the maximum transmit power determination unit applies a power reduction factor associated with the SAR backoff to determine the maximum transmit power.

Mobile station and method for use in radio communication system

A radio communication method for a radio base station, apparatus that controls transmission of an aperiodic SRS (Sounding Reference Signal) by a mobile terminal apparatus is described. The radio communication method includes selecting a specific bit information piece to report to the mobile terminal apparatus, from a table having four bit in formation pieces including one bit information piece to indicate not to trigger the aperiodic SRS and three bit information pieces to indicate to transmit the aperiodic SRS using first to third default SRS parameters respectively, the four bit information pieces all being defined in a 2-bit bit field in downlink control information to be transmitted in one subframe, and transmitting, to the mobile terminal apparatus; the first to third default SRS parameters by higher layers and the specific bit information piece by a downlink control channel.

Radio base station apparatus, mobile terminal apparatus and radio communication method

In order to prevent any increase in number of blind detections and make efficient use of radio resources even when a format of downlink control information is changed in accordance with a communication environment, the present invention provides a radio communication method for generating control information by using a predetermined DCI format out of a plurality of DCI formats including a first DCI format having an uplink scheduling grant and a second DCI format having downlink scheduling assignment. When the first DCI format is extended in size, the second DCI format is added with an information field so as to have the same size as the extended first DCI format, and information to extend an existing function of the second DCI format and/or information to add a new function is added to the information field thereby to generate the control information.

Radio base station apparatus, user terminal and radio communication method

The present invention is designed to provide a radio communication system which can control uplink transmission power adequately even in an HetNet environment. A radio communication system having a first radio base station apparatus and a second radio base station apparatus that is configured to able to communicate with the first radio base station apparatus is provided; and, in this radio communication system, the first radio base station apparatus has a first communication quality measurement section that measures the received quality of an uplink reference signal transmitted from a user terminal, and generates first received quality information, and a reporting section that reports the first communication quality information to the second radio base station apparatus, and the second radio base station apparatus has a second communication quality measurement section that measures the received quality of the uplink reference signal transmitted from the user terminal, and generates second communication quality information, a correction value determining section that determines a correction value for the transmission power of the user terminal on the uplink based on the first communication quality information and the second communication quality information, and a reporting section that reports the determined correction value to the user terminal.

Radio communication system, radio base station apparatus, user terminal and radio communication method

The present invention is designed to minimize the increase of user terminal power consumption even when downlink control channels are extended. A radio base station apparatus having: an allocation section that allocates downlink control information in a first control region from a top of a radio frame to a predetermined OFDM symbol and in a second control region that is frequency-divided with a data region in a region that is time-divided with the first control region, and also allocates decoding control information that indicates a user terminal to perform a decoding process for the second control region, in the first control region; and a transmission section that transmits the downlink control information and the decoding control information; and a user terminal having: a receiving section that receives the downlink control information and the decoding control information from the radio base station apparatus; and a decoding section that controls the decoding process for the second control region based on the decoding control information received, are provided.

User terminal, radio base station apparatus, radio communication system and radio communication method

To ensure stable operation of a user terminal even in the case where the user terminal is instructed to transmit uplink signals at different transmission timings with a plurality of component carriers, in a radio communication system provided with a radio base station apparatus that indicates transmission timings of uplink signals for each component carrier, and a user terminal that transmits an uplink signal at a transmission timing set based on transmission timing information indicated from the radio base station apparatus and the like, it is a feature that the radio base station apparatus indicates different transmission timing information in a plurality of component carriers, and that the user terminal avoids simultaneous transmission of uplink signals in the case of performing communications using a plurality of contiguous component carriers.

Using different transmission timings in radio communication system, user terminal and radio communication method

A radio base station apparatus that reports SRS (Sounding Reference Signal) transmission control information to a mobile terminal apparatus and controls transmission of an SRS by the mobile terminal apparatus is described. The radio base station includes an SRS setting section configured to select bit information to report to the mobile terminal apparatus, from a table having bit information to indicate not to trigger the SRS and bit information to indicate to trigger the SRS using a default SRS parameter and a reporting section configured to report the bit information for the mobile terminal apparatus using a downlink control channel.

The present invention aims to reduce an insertion loss or the like caused by a diplexer inserted to reduce leakage from an uplink bandwidth to a downlink bandwidth of different bands, and thereby to improve a communication quality. A mobile communication method according to the present invention includes the steps of: transmitting simultaneous transmission capability information from a mobile station UE to a radio base station eNB, the simultaneous transmission capability information indicating whether or not the mobile station UE is able to transmit uplink data signal via multiple carriers in multiple bands within a same sub-frame in performing uplink CA; performing scheduling for the mobile station UE by the radio base station eNB based on the simultaneous transmission capability information; and performing communications by the mobile station UE based on the scheduling information.

Mobile communication method, radio base station, and mobile station

It is an object of the present invention to adequately report the SRS transmission timing and SRS parameters to a mobile terminal apparatus, when an aperiodic SRS is adopted, and efficiently use radio resources to be used for SRS transmission. A radio base station apparatus that reports SRS transmission control information to a mobile terminal apparatus and controls transmission of an SRS by the mobile terminal apparatus, and the radio base station apparatus has an SRS setting section that selects bit information to report to the mobile terminal apparatus, from a table having bit information to indicate not to trigger the SRS and bit information to indicate to trigger the SRS using a default SRS parameter, and a reporting section that reports the bit information for the mobile terminal apparatus using a downlink control channel.

An objective is to improve communication quality by reducing an insertion loss or the like of a diplexer inserted to reduce a leakage from an uplink band to a downlink band in different bands. A mobile communication method according to the present invention includes the steps of: transmitting simultaneous transmission capability information from a mobile station UE to a radio base station eNB, the simultaneous transmission capability information indicating whether or not the mobile station UE can transmit uplink data signals via multiple carriers in the same sub-frame while performing uplink CA; performing scheduling for the mobile station UE by the radio base station eNB on the basis of the simultaneous transmission capability information; and performing communication by the mobile station UE on the basis of the scheduling information.

A user equipmentaccording to the present invention is provided with a RSSI measuring unitthat, 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.

User equipment and measurement method

A user equipment () according to the present invention includes an interference removing function capable of removing interference from a neighboring cell, a RSSI measuring unit () 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 () 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.

It is an object of the present invention to provide a reference signal transmitting method, a mobile terminal apparatus and a base station apparatus capable of reducing influences on a PDCCH even when performing transmission control over an aperiodic reference signal for measuring channel quality. Downlink control information corresponding to each component carrier in which transmission control information of a reference signal for measuring channel quality is set is aggregated and assigned to a downlink control channel of a specific component carrier for a mobile terminal apparatus that performs radio communication in a system band containing a plurality of component carriers and transmitted, and when the mobile terminal apparatus controls transmission of the reference signal for measuring channel quality based on the transmission control information of the reference signal for measuring channel quality included in the received downlink control information, the downlink control information corresponding to each component carrier includes a bit field in which identifier information of the component carrier is set and the transmission control information of the reference signal for measuring channel quality is set in the bit field.

Reference signal transmitting method, mobile terminal apparatus and radio base station apparatus

To suppress and minimize changes from the method of transmitting an uplink control information in the LTE system, while supporting increases in the system band and increases in the transmission layer when there is a PUSCH signal transmitted in the same subframe, provided is a configuration for generating a UCI signal for a base station apparatus () in a mobile communication system having a system band comprised of a plurality of component carriers, multiplexing the UCI signal into a PUSCH signal transmitted in the same subframe as the UCI signal in a user specific component carrier used in transmission of a PUCCH signal, and transmitting the PUSCH signal into which the UCI signal is multiplexed to the base station apparatus ().

Growing community of inventors

Tokyo, Japan

Daisuke Nishikawa