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.

Abstract: A base station includes a scheduler configured to perform frequency scheduling for each subframe; a control channel generating unit configured to generate a control channel including common control information to be mapped to radio resources distributed across a system frequency band and specific control information to be mapped to one or more resource blocks allocated to each selected user device; and a transmission signal generating unit configured to generate a transmission signal by time-division-multiplexing the common control information and the specific control information according to scheduling information from the scheduler. The common control information includes a format indicator representing one of preset options that indicates the number of symbols occupied by the common control information in one subframe. The common control information includes information units with a predetermined data size.

Abstract: A base station for communicating with a first user equipment terminal within a first system band and communicating with a second user equipment terminal within a second system band includes a first reference signal sequence generating unit configured to generate M types of reference signal sequences; a second reference signal sequence generating unit configured to generate N (N>M) types of reference signal sequences; a scheduling unit configured to allocate resource blocks to the first user equipment terminal and the second user equipment terminal; a signal multiplexing unit configured to multiplex the M types of reference signal sequences into the resource block for the first user equipment terminal and multiplex the N types of reference signal sequences into the resource block for the second user equipment terminal; and a transmitting unit configured to transmit signals including the M types of reference signal sequences and the N types of reference signal sequences.

Abstract: To suppress deterioration of retransmission efficiency and retransmit a transmission signal efficiently even when the system bandwidth is extended, provided are a base station apparatus (20) which divides, in a retransmission block dividing section (21), a transmission signal into retransmission blocks according to a retransmission block table in which the number of the retransmission blocks each of which is a retransmission unit of a transmission signal is increased corresponding to the number of transmission antennas and registered, and retransmits in downlink transmission signals associated with the divided retransmission blocks, and a mobile terminal apparatus (10) which receives the transmission signals associated with the retransmission blocks from the base station apparatus (20), and combines the retransmission blocks to restore the transmission signal prior to division.

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).

Abstract: A radio communication system includes a first radio base station, second radio base stations, and mobile stations. Each of the mobile stations measures a first reception characteristic value and a second reception characteristic value for respective radio waves. The first radio base station determines the radio base station to which each of the mobile stations should connect, according to the first reception characteristic value, and classifies the mobile stations into a first mobile-station group and a second mobile-station group according to the second characteristic values.

Abstract: In a radio communication system provided with first radio base stations, second radio base stations, and a mobile station, the first radio base stations execute transmission of radio signals to the mobile station, located in first cells, in a first period, and stop the transmission of the radio signals to the mobile station in a second period; and the second radio base stations execute transmission of radio signals to the mobile station, located in second cells, in both the first period and the second period. In the first period, first radio base stations and second radio base stations included in a coordinated-transmission base station set are capable of coordinating with each other to send radio signals, whereas, in the second period, the second radio base stations included in the coordinated-transmission base station set are capable of coordinating with each other to send radio signals.

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.

Abstract: 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.

Abstract: A transmission apparatus for transmitting an uplink control signal by using a predetermined number of basic frequency blocks in a plurality of basic frequency blocks, wherein a system band is divided into a plurality of bands by a basic frequency block having a predetermined bandwidth, includes: a mapping unit configured to map control information to subcarriers in a basic frequency block in a given subframe; an inverse Fourier transform unit configured to perform inverse Fourier transform on a signal to which the control information is mapped; and a radio transmission unit configured to transmit a transmission signal, to a receiving apparatus by radio, including a signal on which inverse Fourier transform has been performed. In a subframe subsequent to the given subframe, the mapping unit maps the control information to subcarriers in a basic frequency block of a band different from a band of the basic frequency block in the given subframe.

Abstract: The present invention is designed such that, when a user terminal performs radio communication using a plurality of serving cells of different component carriers, it is possible to flexibly report aperiodic channel state information of a serving cell required on the network side among the plurality of serving cells. A radio base station apparatus transmits an uplink scheduling grant, which includes an identification field that identifies an uplink serving cell where an uplink shared channel is allocated among a plurality of uplink serving cells and a request field that requests reporting of aperiodic channel state information from a user terminal, to the user terminal, via a downlink control channel, and the user terminal reports aperiodic channel state information of a downlink serving cell that is designated by a combination of the identification field and the request field, to the radio base station apparatus, via the uplink shared channel.

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.

Abstract: A mobile terminal selects a radio base station that is the access point for the mobile terminal in accordance with received-radiowave characteristic values for respective radio base stations. The multiple radio base stations include a macrobase station and multiple picobase stations. Each picobase station includes a load measurement unit adapted for measuring or calculating the communication load index of the picobase station itself; an adjustment-value setting unit adapted for setting an adjustment value that is used by the mobile terminal to change the received-radiowave characteristic value of the picobase station itself, depending on the communication load index; and an adjustment-value signaling unit adapted for signaling the adjustment value set by the adjustment-value setting unit to the mobile terminal.

Abstract: A radio communication system includes a first radio base station that forms a first cell, second radio base stations that form second cells, and mobile stations that execute radio communication with radio base stations.

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.

Abstract: A communication terminal in a multi-carrier system using a frequency bandwidth including a plurality of resource blocks, each of the resource blocks including one or more sub-carriers. The communication terminal includes a receiving unit configured to receive a signal in which a control channel is multiplexed into a single radio frame based on a number of control channels allocated into the single radio frame to use a lower coding rate by repeating transmitting without changing encoding method in which a channel other than the control channel is multiplexed in accordance with scheduling information for allocating one or more of the plurality of resource blocks to the communication terminal and a processing unit configured to perform a process on the signal received by the receiving unit.

Abstract: The present invention provides a mobile terminal apparatus, a base station apparatus, and a communication control method, which allow control suitable for interference reduction in a layered network such as HetNet, and which support a next-generation mobile communication system. A mobile terminal apparatus has a receiving section (103) that receives radio frames of a pico cell, in which a protected subframe, the transmission of which by a macro cell is suppressed, and a non-protected subframe, the transmission of which by the macro cell is not suppressed, coexist, a measurement section (112) that measures reception quality from the reference signals multiplexed individually on the protected subframe and the non-protected subframe, and a transmission section (103) that notifies two types of reception quality information of the protected subframe and the non-protected subframe, measured in the measurement section (112), to a base station apparatus (20B).

Abstract: In order to make transmission power control of a PDCCH signal in an appropriate manner in a communication system having a system band formed with a plurality of fundamental frequency blocks, the present invention provides a radio base station apparatus having: a transmitting section configured to transmit downlink control channel signals for respective fundamental frequency blocks to a mobile terminal apparatus; and a receiving section configured to receive retransmission response signals that are transmitted in a predetermined fundamental frequency block from the mobile terminal apparatus.

Abstract: A disclosed communication control method includes determining a number of bits for transmitting downlink shared data channel information based on one or both of a number of users and a traffic amount and generating a signal for the downlink shared data channel information to be transmitted with the determined number of bits.

Abstract: Provided is a base station comprising a multiplexer so constituted as to frequency-divide/multiplex a first channel for transmitting first data to be transmitted to a plurality of mobile stations, and a second channel for transmitting second data to be transmitted to one mobile station.