Abstract: The present invention is designed to improve spectral efficiency in a radio communication system which can use non-orthogonal multiple access (NOMA). Steps are provided in which a radio base station configures one of a plurality of transmission mode including a first transmission mode, which groups a plurality of transmission methods including a transmission method to employ non-orthogonal multiple access (NOMA) and multiple-user multiple-input and multiple-output (MU-MIMO), and a second transmission mode, which groups a plurality of transmission methods including a transmission method to employ this NOMA and open-loop transmit diversity, and transmits a downlink signal for this user terminal based on the configured transmission mode.

Abstract: Techniques for providing codebooks extended by gain information that can be transmitted in a reduced amount of signaling are disclosed.

Abstract: The present invention is designed to provide a radio base station, a user terminal, a radio communication system and a radio communication method of novel structures that can improve the efficiency of the use of radio resources sufficiently.

Abstract: The present invention is designed to provide a user terminal, a radio base station and a radio communication method of novel structures that can achieve a good communication environment. A radio base station non-orthogonal-multiplexes downlink signals for a plurality of user terminals over a given radio resource, a user terminal having received the downlink signals for the plurality of user terminals decodes downlink signal for another user terminal, judges whether or not the downlink signal for the other user terminal has been successfully received, based on the decoding result of the downlink signal, reports a judgement result as to whether or not the downlink signal for the other user terminal has been successfully received and a judgement result as to whether or not a downlink signal for the user terminal has been successfully received, to the radio base station, and then the radio base station executes retransmission control of downlink signals based on reports from the user terminal.

Abstract: A system in which user terminal is able to aggressively select small cells in a radio communication system in which a macro cell and small cells are arranged to overlap each other is disclosed. A macro base station (M) configured to form a macro cell carries out the steps of determining the offset value to use in cell selection in a user terminal (UE) based on transmission property information of a second carrier in the small cell, and reporting the offset value to the user terminal (UE). Also, the user terminal (UE) carries out the steps of measuring the received quality of reference signals from the macro base station (M) and the small base station (S), receiving the offset value that is reported from the macro base station (M), and carrying out cell selection based on the received quality that is measured and the offset value that is received.

Abstract: The present invention is designed to provide a radio base station, a user terminal, a radio communication method and a radio communication system of novel structures that can achieve improved throughput and system capacity.

Abstract: A method and system for adapting the structure of a codebook for precoding, by changing parameters, in downlink MIMO transmission using a plurality of transmitting antennas, is disclosed. A codebook adaptation method to adapt a codebook for precoding applied to downlink MIMO transmission includes the steps of reporting the codebook size of the codebook, defined with a plurality of parameters pertaining to gain information and phase information, from one communication apparatus to another communication apparatus, and, at the other communication apparatus, adapting the structure of the codebook, based on the codebook size reported from the one communication apparatus.

Abstract: The present invention is designed to provide a radio base station, a user terminal, a radio communication method and a radio communication system of novel structures that can achieve improved throughput and system capacity.

Abstract: The present invention is designed to provide highly efficient local area radio access. A communication system, in which a mobile terminal apparatus (10) detects a local area base station apparatus (30) to connect to, among local area base station apparatuses (30), is configured such that the local area base station apparatuses (30) transmit detection signals to be used to detect the local area base station apparatus (30), to the mobile terminal apparatus (10), in a radio communication scheme for the local areas, which is different from the radio communication scheme for the wide area, and the mobile terminal apparatus (10) transmits detection signal measurement results to the local area base station apparatus (30), through an uplink channel that is defined in the radio communication scheme for the local areas.

Abstract: The present invention is designed to provide highly efficient local area radio access.

Abstract: A method and system for adapting the structure of a codebook for precoding, by changing parameters, in downlink MIMO transmission using a plurality of transmitting antennas, is disclosed. A codebook adaptation method to adapt a codebook for precoding applied to downlink MIMO transmission includes the steps of reporting the codebook size of the codebook, defined with a plurality of parameters pertaining to gain information and phase information, from one communication apparatus to another communication apparatus, and, at the other communication apparatus, adapting the structure of the codebook, based on the codebook size reported from the one communication apparatus.

Abstract: A radio communication method is provided in which beam forming information for forming transmission beams directed from the small base station to the user terminal are generated based on position-related information of the user terminal acquired by communication between the macro base station and the user terminal using a coverage carrier and position-related information of the small base station, and the small base station precodes at least one of a common control signal and a reference signal that are common in a small cell (C2) based on the beam forming information and transmits the precoded signal from a plurality of transmitting antennas using a capacity carrier.

Abstract: The present invention is designed to provide highly efficient local area radio access.

Abstract: To provide a base station apparatus, mobile terminal apparatus and scheduling method for enabling fairness of user throughput to be improved, a scheduling method is characterized by having the steps of notifying a mobile terminal apparatus of allocation information of radio resources to each cluster pattern with a plurality of cluster patterns comprised of clusters formed of a plurality of adjacent sectors predefined and with different radio resources allocated for each of the cluster patterns, receiving channel information•channel quality information corresponding to each of the cluster patterns for each of the radio resources from the mobile terminal apparatus, and controlling allocation of the radio resources to the mobile terminal apparatus, based on the channel information•channel quality information, where at least one of the cluster patterns is a coordinated cluster pattern to perform coordinated transmission between adjacent sectors in a cluster.

Abstract: A method for making the uplink and downlink coverages in a local area symmetrical by executing transmission power control in the downlink of a local area in HetNet is disclosed. A radio communication method is provided in which a local area base station apparatus, arranged in a wide area where a first carrier frequency is used and forming a local area that is narrower than the wide area, transmits a downlink signal, using a second carrier frequency, which belongs to a different frequency band from the first carrier frequency and which has a wider bandwidth than the first carrier frequency, the local area base station apparatus transmits a detection signal that is used to detect the local area base station apparatus in the mobile terminal apparatus, and the local area base station apparatus transmits the downlink signal for the mobile terminal apparatus with transmission power that is determined.

Abstract: A wireless communication method includes a mobile terminal for supporting precoding matrix feedback for multi-user and single-user multiple-input and multiple-output (MIMO) systems. The wireless communication method also includes obtaining, at the mobile terminal, channel state information comprising at least gain information and relative-phase information. Further, the method includes generating precoding matrices comprising bg, p1, p2, and p3 bit groups, wherein each of the precoding matrices are generated by quantization using at least the gain information and the relative-phase information between antenna elements. The method also includes selecting the best precoding matrix among the generated precoding matrices, and transmitting the bit sequence representing the selected precoding matrix to a base station.

Abstract: A radio communication apparatus and radio communication method are provided which coordinates a plurality of radio base station apparatuses in consideration of interference cancelling capability of mobile terminal apparatuses, and can thereby improve the throughput of the entire system even when the amount of information shared among a plurality of radio base station apparatuses is small. In a system that performs multicell coordinated transmission in downlink, a radio communication method according to the present invention selects a set of mobile terminal apparatuses whose interference can be cancelled from a plurality of mobile terminal apparatus, when a plurality of radio base station apparatuses perform joint scheduling, using interference cancelling capability information fed back from each mobile terminal apparatus; then performs joint scheduling for the set of selected mobile terminal apparatuses.

Abstract: To increase the number of CSI-RSs for interference measurement to improve interference measurement accuracy, a first reference signal for channel state measurement and a second reference signal for interference measurement are assigned to reference signal resources defined for transmission of the first reference signal, and a mobile terminal apparatus that supports both the first reference signal and the second reference signal is notified of pattern information to identify an assignment pattern of the first reference signal and the second reference signal. A second mobile terminal apparatus that supports the first reference signal and that does not support the second reference signal is notified of pattern information to identify an assignment pattern of the first reference signal, and of assignment information indicating that resources assigned the second reference signal are assigned a third reference signal of zero power for channel state measurement.

Abstract: The present invention is designed to provide a radio communication system, an interference measurement method, a radio base station apparatus, and a user terminal whereby highly accurate interference measurement is possible.

Abstract: The present invention is designed to measure interference with high accuracy, without changing the density of CSI-RSs, in a future system that does not reply on CRSs. A base station apparatus (20) allocates CSI-RS to CSI resources that are defined for CSI-RS transmission, changes arbitrary resources in the CSI-RS resources in resource block units or in resource block group units, and determines and reports to a mobile terminal apparatus (10) the resources to be muted, and the mobile terminal apparatus (10) is configured to measure interference using the muted resources.