Abstract: A user device for a radio communication system supporting Device-to-Device (D2D) communication is disclosed. The user device includes a transmitter that transmits a D2D signal by mapping a reference signal to a physical channel according to a first mapping configuration or according to a second mapping configuration. The reference signal is mapped to more symbols in the second mapping configuration than in the first mapping configuration. When transmitting the D2D signal by applying the second mapping configuration to a Physical Sidelink Shared Channel (PSSCH), the transmitter of the user device generates parameters for generating the reference signal to be mapped to the PSSCH based on information included in a Physical Sidelink Control Channel (PSSCH).

Abstract: A user apparatus in a mobile communication system includes an allocation means that divides a message that includes control information and data into a plurality of partial messages, and allocates resources included in one or more resource pools to the plurality of partial messages; and a transmission means that transmits the plurality of partial messages using the resources allocated by the allocation means.

Abstract: A user apparatus for use in a mobile communication system that supports D2D communication, including: a signal transmission unit configured to transmit a plurality of D2D signals; and a resource selection unit configured to select, from a predetermined resource pool, a radio resource having a time resource and a frequency resource for transmitting the plurality of D2D signals, wherein the resource selection unit is configured to select the radio resource such that the plurality of D2D signals are not transmitted by a same time resource.

Abstract: A terminal is disclosed including a receiver configured to receive first sidelink control information (SCI) in a first physical sidelink control channel (PSCCH) from another terminal; a processor configured to measure a reception level based on the first PSCCH and determine whether a radio resource for sidelink transmission is usable based on the reception level; and a transmitter configured to transmit data via a physical sidelink shared channel (PSSCH) within the radio resource, wherein the processor is configured to determine to not use the radio resource for transmission when the reception level of the first PSCCH is higher than a threshold. In other aspects, a radio communication system and a communication method are also disclosed.

Abstract: A terminal is disclosed including a processor that detects, based on a result of sensing in a time window for sensing, one or more resources capable of transmitting a physical sidelink shared channel (PSSCH) signal in a time window for resource selection, wherein the processor selects a resource for transmitting the PSSCH signal from the one or more detected resources; and a transmitter that transmits the PSSCH signal using the selected resource for transmitting the PSSCH signal. The processor autonomously determines a start timing and an end timing of the time window for resource selection from preset timing candidates. An end timing of the time window for sensing is right before the start timing of the time window for resource selection.

Abstract: A user equipment communicating with a base station in a wireless communication system including the base station and the user equipment, the user equipment including: a storage unit configured to store correspondence information where an identifier of a beam formed by the base station and configuration information used for transmission of a random access signal are associated with each other; a selection unit configured to select a specific beam on the basis of reception quality of signals transmitted from the base station by using a plurality of different beams and select configuration information corresponding to the specific beam on the basis of the correspondence information; and a transmission unit configured to transmit the random access signal to the base station by using the configuration information selected by the selection unit.

Abstract: A user equipment that is provided in a wireless communication system including a base station and the user equipment includes an acquisition unit that acquires information indicating a resource position where a downlink data channel is mapped or a resource position where an uplink data channel is mapped in a radio frame and a timing when an HARQ response to downlink data is transmitted from the user equipment or a timing when an HARQ response to uplink data is received from the base station and a communication unit that transmits an HARQ response to downlink data received by the downlink data channel at a timing when the HARQ response to the downlink data is transmitted and receives an HARQ response to data transmitted by the uplink data channel or retransmission data scheduling information at a timing when the HARQ response to the uplink data is received.

Abstract: A terminal is disclosed that includes a first transmitter configured to transmit control information for D2D by using a physical control channel for D2D multiplexed with a physical data channel for D2D in a frequency domain and a second transmitter configured to transmit data corresponding to the control information for D2D by using the physical data channel for D2D, where a plurality of the control information for D2Ds are mapped in a wireless resource unit. In other aspects, another terminal is also disclosed.

Abstract: A user apparatus for use in a mobile communication system that supports D2D communication, including: measurement gap control means configured to transmit a configuration request of a measurement gap for monitoring a different frequency D2D signal to a base station of a connecting or residing cell; and D2D communication means configured to monitor the different frequency D2D signal by using the measurement gap that is configured based on the configuration request.

Abstract: A terminal is disclosed including a receiver configured to receive first sidelink control information (SCI) in a first physical sidelink control channel (PSCCH) from another terminal; a processor configured to measure a reception level based on the first PSCCH and determine whether a radio resource for sidelink transmission is usable based on the reception level; and a transmitter configured to transmit data via a physical sidelink shared channel (PSSCH) within the radio resource, wherein the processor is configured to determine to not use the radio resource for transmission when the reception level of the first PSCCH is higher than a threshold. In other aspects, a radio communication system and a communication method are also disclosed.

Abstract: The present invention is designed to allow adequate communication in a next generation communication system in which a plurality of numerologies are introduced. A control section that controls communication using at least one of a plurality of numerologies with different subcarrier spacings, and a receiving section that receives information related to numerology for use in communication are provided, and the plurality of numerologies with different subcarrier spacings are configured that one of the length of a transmission time interval (TTI) and the number of symbols per TTI is different.

Abstract: The present invention is designed to optimize the uplink access procedure even when the band to use is limited to partial narrow bands in a system band. A user terminal, in which the band to use is limited to a partial narrow band in a system band, has a receiving section that receives system information that includes indication information of an uplink carrier frequency, from a radio base station, as system information for narrow bands, which is different from system information for the system band, and a transmission section that transmits a random access preamble to the radio base station in one of a plurality of narrow bands that are specified by the indication information of the uplink carrier frequency.

Abstract: A terminal is disclosed that includes a receiver that receives sidelink control information and data in sidelink and a transmitter that transmits a feedback signal corresponding to the data on a sidelink feedback channel. The transmitter determines a resource for transmitting the feedback signal based on a correspondence between a resource of the data and a resource for feedback. In other aspects, a base station, systems, and feedback methods are also disclosed.

Abstract: Provided is a user equipment in a radio communication system including a base station and the user equipment. The user equipment includes: a reception unit that receives an instruction related to a calculation method of a channel quality indicator, which is to be reported to the base station, from the base station; and a reporting unit that reports an index of a channel quality indicator, which is calculated in accordance with the instruction related to the calculation method of the channel quality indicator, to the base station.

Abstract: A terminal is disclosed including a processor that detects, based on a result of sensing in a time window for sensing, one or more resources capable of transmitting a physical sidelink shared channel (PSSCH) signal in a time window for resource selection, wherein the processor selects a resource for transmitting the PSSCH signal from the one or more detected resources; and a transmitter that transmits the PSSCH signal using the selected resource for transmitting the PSSCH signal. The processor autonomously determines a start timing and an end timing of the time window for resource selection from preset timing candidates. An end timing of the time window for sensing is right before the start timing of the time window for resource selection.

Abstract: A user apparatus for use in a mobile communication system that supports Device-to-Device (D2D) communication, including a receiver that receives a resource for D2D communication assigned from a base station in the mobile communication system; a transmitter that transmits a D2D signal to another user apparatus by using the resource for D2D communication assigned from the base station; and a processor that generates a resource release request signal for requesting release of the resource for D2D communication assigned from the base station, wherein the transmitter transmits, to the base station, the resource release request signal for requesting release of the resource for D2D communication assigned from the base station, and wherein the transmitter transmits a resource request signal to the base station as the resource release request signal for requesting release of the resource.

Abstract: There is provided user equipment that supports D2D communication and cellular communication, the user equipment including a receiver that receives a radio parameter for the D2D communication corresponding to radio quality of a downlink signal transmitted from a base station or a propagation delay between the base station and the user equipment; and a communication unit that performs the D2D communication using the received radio parameter for the D2D communication corresponding to the radio quality or the propagation delay.

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: A user apparatus for use in a mobile communication system that supports D2D communication, including: a signal transmission unit configured to transmit a plurality of D2D signals; and a resource selection unit configured to select, from a predetermined resource pool, a radio resource having a time resource and a frequency resource for transmitting the plurality of D2D signals, wherein the resource selection unit is configured to select the radio resource such that the plurality of D2D signals are not transmitted by a same time resource.

Abstract: There is provided user equipment that selects a resource for transmitting a signal based on a sensing result. The user equipment includes a detection unit that detects, by performing sensing in a time window for sensing, one or more resources capable of transmitting a signal in a time window for resource selection after the time window for sensing; a selection unit that selects a resource for transmitting a signal from the one or more detected resources; and a transmission unit that transmits the signal using the selected resource for transmitting the signal.