Abstract: A user apparatus for use in a mobile communication system that supports D2D communication, including: D2D communication means that transmits a D2D signal to another user apparatus by using a resource for D2D communication assigned from a base station in the mobile communication system; and resource control means that transmits, to the base station, a resource release request signal for requesting release of a resource for D2D communication assigned from the base station.

Abstract: A user apparatus is provided. The user apparatus includes a cyclic prefix length detection unit configured to detect a cyclic prefix length used by a user apparatus of a neighbor cell or out of coverage; and an interference detection unit configured to detect interference caused by a cyclic prefix length difference, a synchronization timing difference, or collision of resources used for signal transmission. Further, a base station is provided. The base station includes a reception unit configured to receive from a user apparatus an interference result caused by a cyclic prefix length difference; a resource allocation unit configured to set resources based on the received interference result; and a transmission unit configured to transmit the set resource information to the user apparatus.

Abstract: User equipment for receiving a discovery signal to be used for inter-user equipment discovery includes a discovery signal receiver that receives the discovery signal transmitted, within a resource pool for transmitting the discovery signal, from any other user equipment; a collision detector that detects collision of discovery signals; and a reporting unit that reports a detected result of the collision to a base station.

Abstract: A user equipment apparatus for performing user equipment-to-user equipment communication includes a synchronization signal detection unit configured to detect a user equipment-to-user equipment synchronization signal transmitted from a user equipment apparatus in another cell or another carrier; a control unit configured to set reception timing based on the user equipment-to-user equipment synchronization signal; and a reception unit configured to receive scheduling information or a discovery signal transmitted from the user equipment apparatus in the other cell or the other carrier within a time window defined based on the user equipment-to-user equipment synchronization signal.

Abstract: The present invention is designed to realize RACH traffic off-loading. A radio communication terminal communicates with a radio base station by using a carrier that is different from the connecting carrier and includes an unlicensed band, and has a transmission section that transmits a cross-carrier RACH in the carrier including the unlicensed band, and a receiving section that receive a random access response that is transmitted from the radio base station having received the cross-carrier RACH.

Abstract: A user apparatus that performs D2D communication by radio includes a signal transmission unit configured to transmit a signal including a destination identifier of a physical layer associated with a destination identifier of an upper layer which is a layer higher than the physical layer; and a signal reception unit configured to detect a signal addressed to the user apparatus by detecting an identifier, of the physical layer of the user apparatus, that is associated with an identifier of the upper layer of the user apparatus from a signal received by radio.

Abstract: A radio base station is disclosed. The radio base station includes a transmitting/receiving section that carries out transmission and reception with a user terminal by using frequency-divisioned paired bands, a control section that applies control so that UL communication and DL communication are carried out in at least one band of the paired bands, and a generating section that generates downlink control signals to control UL communication and DL communication in the one band. The control section applies control so that the downlink control signals are transmitted from the other band paired with the one band, or from another component carrier.

Abstract: The present invention aims at reducing or avoiding PUCCH conflict among terminals if a PDSCH and a PDCCH for indicating assignment information required to receive the PDSCH are transmitted in different subframes.

Abstract: For the purpose of preventing transmission of UL signals in a subframe other than a UL subframe during the fallback operation in Dynamic TDD communication, the present invention provides a user terminal for communicating in Dynamic TDD, the user terminal having: a reception section that receives control information including an indication to dynamically change a subframe configuration of a Dynamic TDD cell and a control section that controls not to perform specific resource transmission in flexible subframes in the fallback operation based on the subframe configuration of Dynamic TDD cell signaled by higher layers or SIB1.

Abstract: The present invention is designed to realize dynamic TDD that is based on TDD-FDD CA. A user terminal, by employing carrier aggregation or dual connectivity, performs radio communication via a plurality of cells including a primary cell, which is an FDD cell, and a secondary cell, which is a dynamic TDD cell, and has a receiving section that receives control information transmitted from the primary cell, and a cell-specific downlink signal transmitted from the dynamic TDD cell, and a control section that decides whether one or a plurality of subframes in the dynamic TDD cell are uplink subframes or downlink subframes based on the control information, and controls operations with respect to the dynamic TDD cell, and the control section executes control so that a subframe to receive the cell-specific downlink signal from the dynamic TDD cell and a subframe to retransmit uplink data are different.

Abstract: The present invention is designed to implement dynamic TDD that does not rely on TDD-FDD CA-based TDD UL-DL configurations. A user terminal executes radio communication with a plurality of cells by employing carrier aggregation, and has a receiving section that, when a connection is established with a secondary cell serving as a dynamic TDD cell, receives control information, which is transmitted from a primary cell and which includes a dynamic command with respect to a subframe configuration of the dynamic TDD cell, and a transmission timing of an uplink signal, and a control section that decides whether or not one or a plurality of subframes in the dynamic TDD cell are uplink subframes or downlink subframes based on the control information, and, furthermore, controls the transmission timing of the uplink signal based on the transmission timing.

Abstract: The present invention is designed to implement dynamic TDD that does not rely on TDD-FDD CA-based TDD UL-DL configurations. A user terminal executes radio communication with a plurality of cells by employing carrier aggregation, and has a receiving section that, when a connection is established with a secondary cell serving as a dynamic TDD cell, receives control information, which is transmitted from a primary cell and which includes a dynamic command with respect to a subframe configuration of the dynamic TDD cell, and a control section that decides whether or not one or a plurality of subframes in the dynamic TDD cell are uplink subframes or downlink subframes based on the control information, and, furthermore, controls operations pertaining to the dynamic TDD cell.

Abstract: The present invention is designed so that communication overhead pertaining to control signals is reduced in a communication system in which the bandwidth of a physical downlink shared channel is narrower than the system bandwidth. The radio base station of the present invention has a resource allocation section that allocates a physical downlink shared channel to a predetermined narrow band in a downlink system bandwidth, for a user terminal, and a downlink control information generating section that generates downlink control information to report to the user terminal, and the downlink control information generating section determines the size of a field pertaining to resource allocation information, included in downlink control information related to the physical downlink shared channel, based on the narrow band where the physical downlink shared channel is allocated.

Abstract: The present invention is designed so that PRACH transmission is carried out taking coverage enhancement into account. A radio communication terminal employs coverage enhancement and has a transmitting section that transmits a random access preamble by using a radio resource that is stipulated for the radio communication terminal employing coverage enhancement, and, in this radio communication terminal, one or a combination of the time, the frequency band and the sequence of the radio resource that is stipulated for the radio communication terminal employing coverage enhancement is different from that of a radio resource that is stipulated for a radio communication terminal not employing coverage enhancement.

Abstract: A base station is configured to transmit control information to a terminal device in a radio communication system, wherein an error detection code that is masked by predetermined identification information is attached to the control information, the base station including a generator configured to generate, upon detecting that a length of first information that is to be masked by the predetermined identification information to generate the error detection code does not correspond to a length of the predetermined identification information, second information that corresponds to the length of the predetermined identification information; and an error detection code generator configured to generate, upon detecting that the second information is generated, the error detection code in which the second information is masked by the predetermined identification information.

Abstract: A radio base station establishes radio synchronization by using a downlink signal transmitted from a radio base station of another cell, and has a synchronization information control section that, via an inter-base station interface, reports a synchronization information request to the radio base station of the other cell and also acquires synchronization information reported from the radio base station of the other cell, and an on/off control section that, based on the synchronization information acquired, determines the status of synchronization with a cell that belongs to a lower stratum than an own cell, and executes on/off control for the own cell, and the synchronization information which the synchronization information control section acquires from the radio base station of the other cell includes information representing the synchronization status and the synchronization stratum level of the radio base station of the other cell.

Abstract: The present invention is designed to establish synchronization properly even when synchronizing between different cells by means of a radio interface in an asynchronous NW.

Abstract: The present invention is designed to enable adequate feedback on the uplink even when CA and CoMP are employed between a plurality of radio base stations (inter-eNB CoMP/CA). A receiving section that receives downlink signals from a first radio base station that forms a first cell and a second radio base station that forms a second cell, a generating section that generates a feedback signal in response to the downlink signal from each radio base station, and a control section that assigns the feedback signal in response to the downlink signal from the first radio base station to an uplink control channel and/or an uplink shared channel on the first cell depending on whether or not there is a UL grant, and assigns the feedback signal in response to the downlink signal from the second radio base station to the uplink shared channel on the first cell or the second cell regardless of whether or not there is the UL grant, are provided in a user terminal.

Abstract: The present invention is designed to use radio resources effectively and improve the throughput of a radio communication system even when a plurality of small cells are placed densely. A radio base station controls the connecting cell of a user terminal, and has a selection section that selects candidate cells, the received power and/or the received quality of which in the user terminal is equal to or greater than a predetermined value, and a determining section that calculates the amount of data to transmit to serving user terminals, for each candidate cell, by taking into account the frequency band that is used, and determines a candidate cell where the amount of data is small, as the connecting cell of the user terminal.

Abstract: The present invention is designed to control inter-cell interference adequately even when a plurality of cells are placed at a high density. A user terminal can connect with a plurality of radio base stations, and has a receiving section that receives a downlink signal from each radio base station, and a power control section that, when an uplink grant or a downlink assignment and a control signal for power control are detected at the same time from the downlink signal, prioritizes a TPC command contained in the control signal for power control, and changes transmission power.