User equipment and communication method

A user equipment in a radio communication system that supports D2D communication, the user equipment comprising:

• an acquisition unit that acquires carrier information indicating whether each of multiple carriers allocated to the radio communication system is used commonly for communication between a base station and the user equipment and D2D communication or used only for the D2D communication;
• and
• a transmission unit that when a D2D signal is to be transmitted using a carrier used only for the D2D communication, transmits the D2D signal using a radio frame where a D2D physical control channel and a D2D physical data channel are time-multiplexed.

A communication method performed by a user equipment in a radio communication system that supports D2D communication, the communication method comprising:

• receiving a first region in a radio frame, which is commonly used for downlink communication and uplink communication with a base station and includes the first region to which a downlink pilot signal and a downlink control signal are to be mapped and a second region to which downlink user data or uplink data is to be mapped, and thereby determining whether a D2D signal is transmittable using the second region;
• and
• transmitting the D2D signal using the second region in the radio frame where a D2D physical control channel and a D2D physical data channel are time-multiplexed when it is determined in the determining that the D2D signal is transmittable.

A communication method performed by a user equipment in a radio communication system that supports D2D communication, the communication method comprising:

• acquiring carrier information indicating whether each of multiple carriers allocated to the radio communication system is used commonly for communication between a base station and the user equipment and D2D communication or used only for the D2D communication;
• and
• when a D2D signal is to be transmitted using a carrier used only for the D2D communication, transmitting the D2D signal using a radio frame where a D2D physical control channel and a D2D physical data channel are time-multiplexed.