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: A mobile communication terminal includes an interference rejection combining processor for obtaining a received signal vector with regard to each of multiple resource elements and for calculating receiving weights so as to suppress influence to a desired beam of electric wave sent from the desired base station by other beams, on the basis of the received signal vectors; a non-interference-rejection receiving weight calculator for calculating receiving weights so as not to suppress influence to the desired beam by other beams; a signal separator for separating a signal destined for the mobile communication terminal from signals destined for other mobile communication terminals; and an interference rejection combining determiner for determining whether the receiving weights to suppress influence by other beams or the receiving weights calculated by the non-interference-rejection receiving weight calculator should be used for signal separation by the signal separator, on the basis of an index representing a rela

Abstract: The present invention provides a base station apparatus, a mobile terminal apparatus and a communication control method which can improve the accuracy of channel quality estimation. A communication control method includes the steps of: arranging a CSI-RS, which is a reference signal for downlink channel estimation, in resources of subframes for CSI-RS transmission; setting, in the subframes for CSI-RS transmission, resources to which the CSI-RS is allocated in neighboring areas, to be muting resources; and reporting transmission interval information, which indicates a transmission interval of subframes that are set at the same timing in a transmission cycle of a subframe for CSI-RS transmission in a subject area and in a transmission cycle of a subframe for CSI-RS transmission in the neighboring areas, to a mobile terminal apparatus.

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.

Abstract: A mobile communication terminal including multiple receiving antennas demodulates an interfering UE-specific reference signal that might be used in another mobile communication terminal, and analyzes interference parameters specified by the interfering UE-specific reference signal demodulated by the interfering UE-specific reference signal demodulator, the interference parameters being parameters with regard to another beam sent to another mobile communication terminal from an interfering base station. Then, the mobile communication terminal calculates receiving weights so as to suppress influence to the desired beam from other beams, on the basis of desired beam parameters and the interference parameters.

Abstract: A radio communication system includes a user device, base stations, and a communication control device. The communication control device generates and reports, to the user device, selection information that is used to select base stations with which the user device should maintain synchronization. The user device selects, based on the selection information, base stations with which the user device should maintain synchronization. The user device reports, to the communication control device, identifiers of the selected base stations and received levels of radio waves transmitted from the base stations corresponding to the identifiers. The user device maintains synchronization with each of the selected base stations.

Abstract: In a radio communication system in which a high-power base station and a low-power base station collaborate for inter-cell interference control, the downlink transmission power at the high-power base station is suitably controlled. The high-power base station executes wireless transmission to the user terminals using resources that are the same as resources used by the low-power radio base station. A transmission power controller of the radio base station uses a first downlink transmission power at first resources and uses a lower second downlink transmission power at second resources. The transmission power controller adjusts the second downlink transmission power in accordance with the number of user terminals capable of executing interference rejection combining, the downlink traffic amount for user terminals capable of executing interference rejection combining, or the number of downlink resource blocks allocated to user terminals capable of executing interference rejection combining.

Abstract: Resources available for large power base stations are controlled in a radio communication system in which mobile terminals with and without interference suppression capability are used together and in which a large power base station and small power base stations coordinate inter-cell interference control. A radio base station coordinates inter-cell interference control with at least one second radio base station forming a second cell within a first cell of the radio base station, the second cell having a smaller area than the first cell. The radio base station has a resource setter for setting a ratio of a first resource in which the radio base station is to execute radio communication and a second resource in which the radio base station is to stop radio communication according to the ratio of the number of mobile terminals capable of executing interference rejection combining to the total number of mobile terminals connecting to the radio base station or to at least one second radio base station.

Abstract: In a radio communication system including multiple mobile terminals and multiple radio base stations, the mobile terminal has a function of interference rejection combining. The radio base stations share downlink channel characteristics for mobile terminals connected to radio base stations. The radio base station gives weights to radio waves transmitted from multiple transmission antennas to perform in-phase addition of an interfering radio wave beam directed to a mobile terminal for which the desired radio base station is another radio base station to an interfering radio wave beam transmitted from yet another radio base station for limiting the number of interfering radio wave beams that arrive at the mobile terminal. The radio base station does not perform in-phase addition when the number of interfering radio wave beams of which interference can be suppressed by the mobile terminal is equal to or greater than the number of radio base stations that send interfering radio wave beams to the mobile terminal.

Abstract: Provided are a base station apparatus, a mobile terminal apparatus and a communication control method capable of selecting a CSI-RS arrangement flexibly in accordance with a system configuration. The base station apparatus has a CSI-RS arrangement section (211) configured to arrange a CSI-RS in a resource reserved for broadcasting when a mobile terminal apparatus (10) is notified of position information of the CSI-RS by broadcasting or in a resource associated with an cell ID of a serving area when the mobile terminal apparatus (10) obtains the position of the CSI-RS based on the cell ID; an identification information generating section (212) configured to generate an identification bit for identifying whether the CSI-RS is arranged in the resource reserved for broadcasting or in the resource associated with the cell ID; and a transmission/reception section (203) configured to transmit the identification information to the mobile terminal apparatus.

Abstract: Provided is a receiver to improve the accuracy of estimating a covariance matrix RI+N based on a data signal. In an IRC receiver 10 according to the present invention, a data signal is configured to be transmitted in an SFBC pair including two resource elements, an estimated covariance matrix RI+N is configured to include a first covariance matrix RI+N (2m) including a desired signal component in even-numbered resource elements in the SFBC pair and a second covariance matrix RI+N (2m+1) including a desired signal component in odd-numbered resource elements in the space frequency block coding scheme unit, and a covariance matrix averaging unit 13 and a covariance matrix generation unit 16 are configured to perform, as the aforementioned predetermined process, an averaging process on each of elements in the first covariance matrix RI+N (2m) and elements in the second covariance matrix RI+N (2m+1).

Abstract: A radio communication system includes multiple radio base stations and multiple mobile communication terminals. Each mobile communication terminal measures a reception quality of radio waves from each radio base station. A first mobile communication terminal that can execute interference rejection combining offsets the reception quality value of radio waves from a second radio base station by using a first bias value. A second mobile communication terminal that cannot execute interference rejection combining offsets the reception quality value of radio waves from the second radio base station by using a second bias value that is lower than the first bias value. The first radio base station selects, as the radio access point for the mobile communication terminal, a radio base station corresponding to a reception quality value indicating a best reception quality among the first reception power value and the offset second reception power value.

Abstract: The IRC receiver 10 according to the present invention includes a channel estimation unit 11 that performs a channel estimation process so as to estimate a channel matrix H, a transmission weight matrix generation unit 13 that generates a transmission weight matrix WTx, a covariance matrix estimation unit 12 that estimates an interference signal covariance matrix (I) including a covariance matrix RI+N and an interference signal component on the basis of CRS, an IRC reception weight generation unit 14 that generates an IRC reception weight WIRC on the basis of the channel matrix H, the transmission weight matrix WTx, and the covariance matrix RI+N, and a received SINR estimation unit 15 that estimates received SINR on the basis of the channel matrix H, the interference signal covariance matrix (I), the transmission weight matrix WTx, and the IRC reception weight WIRC.

Abstract: Appropriate reception processing is performed using a CRS-based estimation method for a covariance matrix RI+N. An IRC receiver 10 according to the present invention includes: a covariance matrix estimation unit 12/13 configured to estimate a covariance matrix RI+N based on a CRS; a missing element insertion unit 14 configured to insert a given value into an inestimable element in an interference-signal covariance matrix RI+N (“˜” is on R) of interference signal components contained in the estimated covariance matrix RI+N; an IRC reception weight generation unit 16 configured to generate an IRC reception weight WIRC by using the control signal and the covariance matrix RI+N having the given value inserted thereinto; and a signal separation unit 17 configured to separate the data signal from a received signal by using the generated reception weight and the control signal.

Abstract: The radio communication system of the present invention is provided with a cluster pattern determining section that determines the assignment of each cluster pattern to each cluster so as to suppress inter-cluster interference with other neighboring clusters less than or equal to a predetermined value, the cluster pattern is defining a directional pattern of which directional beams emitted from the respective radio base stations face each other for each identical frequency block between neighboring sectors in a cluster composed of neighboring cells, the each cluster pattern being in different combinations of directional patterns and frequency blocks.

Abstract: A coordinated transmission method of the invention has the steps of selecting a directional pattern corresponding to an area in which a radio terminal locates, from among a plurality of directional patterns determined respectively corresponding to a plurality of resources in frequency domains where the plurality of directional patterns is configured so that a plurality of radio base stations surrounding the area transmits, to the area, directional beams of same frequency domain resources to face one another, while not transmitting the directional beams of the same frequency domain resources using the same frequency domain resources to areas adjacent to the area, and of distributing a signal to transmit to the radio terminal according to the selected directional pattern, determining a frequency domain and directions of directional beams regarding the distributed signal, and delivering the signal to each of the plurality of radio base stations that simultaneously transmits the signal to the radio terminal.

Abstract: The present invention provides a radio communication system which includes a plurality of radio base station apparatuses that transmit reference signals orthogonal to each other among a plurality of transmitting antennas and a mobile terminal apparatus that performs channel estimation based on the reference signals transmitted from the plurality of radio base station apparatuses, sets priority among a plurality of neighboring radio base station apparatuses and introduces a bias in the number of reference signals that can be allocated to each radio base station apparatus according to the priority from the radio resources shared among the plurality of neighboring radio base station apparatuses.

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: 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.

Abstract: The present invention provides a base station apparatus, a mobile terminal apparatus and a communication control method which can improve the accuracy of channel quality estimation. A communication control method includes the steps of: allocating a CSI-RS (Channel State Information-Reference Signal), which is a reference signal for downlink channel estimation, in resources for the CSI-RS that are defined for CSI-RS transmission; setting to muting resources in the resources for the CSI-RS; and reporting parameters to specify the CSI-RS, including at least a transmitting subframe cycle, a subframe offset and transmission power, to a mobile terminal apparatus.