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 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.

Abstract: The present invention is designed to provide a radio base station apparatus, a mobile terminal apparatus, a radio communication system and a radio communication method which can cope with an increased number of users. A radio base station apparatus is provided with: a signal generating section that generates a first downlink control signal and a second downlink control signal for a mobile terminal apparatus; a first multiplexing section that multiplexes the first downlink control signal on a control region up to a predetermined number of symbols from the top of a subframe; a second multiplexing section that frequency-division-multiplexes the second downlink control signal on radio resources from the next symbol in the control region to the last symbol of the subframe; and a transmission section that transmits the first downlink control signal multiplexed on the control region and the second downlink control signal multiplexed on the radio resources.

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.

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.

Abstract: The present invention is designed to provide a radio base station apparatus, a mobile terminal apparatus, a radio communication system and a radio communication method which can cope with an increased number of users. A radio base station apparatus is provided with: a signal generating section that generates a first downlink control signal and a second downlink control signal for a mobile terminal apparatus; a first multiplexing section that multiplexes the first downlink control signal on a control region up to a predetermined number of symbols from the top of a subframe; a second multiplexing section that frequency-division-multiplexes the second downlink control signal on radio resources from the next symbol in the control region to the last symbol of the subframe; and a transmission section that transmits the first downlink control signal multiplexed on the control region and the second downlink control signal multiplexed on the radio resources.

Abstract: The present invention is designed to perform CQI measurement for adjacent cells without making the processes in the user terminal UE complex. A base station apparatus (eNodeB #1) provided in the serving cell has features of acquiring, from a base station apparatus (eNodeB #2) provided in an adjacent cell, the cell ID of the adjacent cell, and the position and transmission power of the CSI-RS, as parameters related to the CSI-RS of the adjacent cell, generating a broadcast signal including the above parameters related to the CSI-RS, and transmitting the generated signal to the user terminal (UE).

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.

Abstract: The present invention is designed to reduce the space to install antennas and still increase the system capacity despite the state of the distribution of user terminals in cells. According to the radio communication method of the present invention, a radio base station apparatus selects precoding vectors from a codebook that is set in advance to be uneven with respect to the direction of the arrangement of antenna elements, based on communication quality information of the user terminals in the cell, multiplies signals to supply to each antenna element by the selected precoding vectors, and transmits the signals multiplied by the precoding vectors to the user terminals, and the user terminal receives a signal from the radio base station apparatus, extracts a reference signal from the received signal and measures channel quality; and feeds back a communication quality feedback signal, including the measured channel quality, to the radio base station apparatus, via the uplink.

Abstract: The present invention is designed to enable a radio base station apparatus to adequately estimate a coordinated cell to cause interference upon CoMP transmission, and effectively execute CoMP transmission. A radio communication system, according to the present invention, includes a plurality of radio base station apparatuses, and a user terminal (UE) that is configured to be able to perform coordinated multiple point transmission/reception with the plurality of radio base station apparatuses, where the user terminal (UE) has a transmission section that transmits information to use to estimate a candidate cell to be an interference cell upon coordinated multiple point transmission, and the radio base station apparatus has an estimation section that estimates a candidate cell to be an interference cell upon coordinated multiple point transmission based on the information.

Abstract: Provided are a radio base station apparatus, a mobile terminal apparatus and a radio communication method capable of taking other-cell interference mitigation measures even in consideration of inter-cell coordination like CoMP. The radio communication method according to the present invention is characterized by, in a radio base station apparatus, generating notification information including subframe information of a serving cell and subframe information of another cell; and transmitting the notification information to a mobile terminal apparatus connected to the serving cell as a connected cell; and in the mobile terminal apparatus, receiving the notification information including the subframe information of the connected cell and the subframe information of another cell; and measuring channel quality of the connected cell with use of the subframe information of the connected cell and measuring channel quality of another cell with use of the subframe information of another cell.

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.

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.

Abstract: To signal CSI-RS location indexes indicative of CSI-RS location positions in a resource block with high efficiency, a signaling method of CSI-RS is characterized by having the steps of locating a CSI-RS that is a reference signal for downlink channel estimation in resources for CSI-RS reserved to transmit the CSI-RS, generating a CSI-RS location index indicative of a location position of the CSI-RS located in the resources for CSI-RS, in the CSI-RS location index an index pattern varies corresponding to the number of CSI-RS ports so that an index pattern of the relatively low number of CSI-RS ports is a subset of an index pattern of the relatively high number of CSI-RS ports, and transmitting the generated CSI-RS location index to a mobile terminal apparatus.

Abstract: The present invention is designed to apply CoMP transmission/reception flexibly in a system band that is formed with a plurality of fundamental frequency blocks, improve received quality in user terminals, and also widen the system band.

Abstract: The present invention is designed to flexibly report aperiodic channel state information to a plurality of radio base station apparatuses to be coordinated, even when coordinated multiple-point (CoMP) transmission/reception is performed.

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: 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.

Abstract: To provide a base station apparatus, mobile terminal apparatus and communication control method for enabling control adapted to interference inside a Heterogeneous network to be performed to support the next-generation mobile communication system, a base station apparatus (20) shares at least a part of the frequency band with another base station apparatus (40) that covers a macro-cell, covers a pico-cell (C1), is capable of transmitting a downlink transmission frame at transmission timing different from the another base station apparatus (40), and is configured to set resources, in which the downlink transmission frame undergoes interference from another downlink transmission frame including a blank period transmitted from the another base station apparatus (40), as blank resources, and assign user data to the downlink transmission frame while avoiding the blank resources.

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: To efficiently detect feedback control information on downlink shared data channel signals transmitted with a plurality of base frequency blocks also in the case of performing radio communications with a system band comprised of a plurality of base frequency blocks, it is a feature to have detecting sections (208, 210) configured to detect a correlation value between an ACK/NACK signal received in uplink and each of ACK/NACK candidate replicas associated with ACK and NACK in response to a downlink shared data channel signal of a particular base frequency block assigned to the mobile terminal apparatus among a plurality of base frequency blocks or of each of a plurality of base frequency blocks, and an A/N·DTX determining section (211) configured to determine feedback control information on the downlink shared data channel signal of the particular base frequency block or of each of the plurality of base frequency blocks, based on the detected correlation value and a DTX determination threshold value.