Terminal device, base station device, and communication method

A base station device that communicates with a terminal device, the base station device comprising:

• a higher layer processor configured to perform one or more second physical downlink control channel (PDCCH) settings in the terminal device through signaling of a higher layer;
• and
• a transmitter configured to map a first PDCCH to a common search space or a terminal device-specific search space in the first PDCCH and transmit the first PDCCH in a case in which the second PDCCH setting is not performed, and map a second PDCCH to a terminal device-specific search space in at least the second PDCCH and transmit the second PDCCH in a case in which the second PDCCH setting is performed, wherein the first PDCCH is transmitted on a basis of a sub frame defined in accordance with a predetermined number of symbols,
• wherein the second PDCCH is transmitted on a basis of an extended sub frame of a smaller number of symbols than a number of symbols corresponding to the sub frame, and a resource block set through the second PDCCH setting, and
• wherein the terminal device transmits capability information which indicates whether or not a physical downlink shared channel (PDSCH) scheduled by the second PDCCH can be scheduled by the first PDCCH.

A communication method used in a terminal device that communicates with a base station device, the communication method comprising:

• performing one or more second physical downlink control channel (PDCCH) settings through signaling of a higher layer from the base station device;
• monitoring only a common search space and a terminal device-specific search space in a first PDCCH in a case in which the second PDCCH setting is not performed, and monitoring a terminal device-specific search space in at least a second PDCCH in a case in which the second PDCCH setting is performed;
• and
• transmitting capability information which indicates whether or not a physical downlink shared channel (PDSCH) scheduled by the second PDCCH can be scheduled by the first PDCCH,
• wherein the first PDCCH is transmitted on a basis of a sub frame defined in accordance with a predetermined number of symbols, and
• wherein the second PDCCH is transmitted on a basis of an extended sub frame of a smaller number of symbols than a number of symbols corresponding to the sub frame, and a resource block set through the second PDCCH setting.

A communication method used in a base station device that communicates with a terminal device, the communication method comprising:

• performing one or more second physical downlink control channel (PDCCH) settings in the terminal device through signaling of a higher layer;
• and
• mapping a first PDCCH to a common search space or a terminal device-specific search space in the first PDCCH and transmitting the first PDCCH in a case in which the second PDCCH setting is not performed, and mapping a second PDCCH to a terminal device-specific search space in at least the second PDCCH and transmitting the second PDCCH in a case in which the second PDCCH setting is performed,
• wherein the first PDCCH is transmitted on a basis of a sub frame defined in accordance with a predetermined number of symbols,
• wherein the second PDCCH is transmitted on a basis of an extended sub frame of a smaller number of symbols than a number of symbols corresponding to the sub frame, and a resource block set through the second PDCCH setting, and
• wherein the terminal device transmits capability information which indicates whether or not a physical downlink shared channel (PDSCH) scheduled by the second PDCCH can be scheduled by the first PDCCH.