A terminal apparatus comprising: a receiving section configured to receive a first physical downlink control channel, PDCCH, and a first physical downlink shared channel, PDSCH, on a first component carrier and to receive a second PDCCH and a second PDSCH on a second component carrier, the first PDCCH including a first transmission power control, TPC, field, the first PDSCH including first downlink data, the second PDCCH including a second TPC field, and the second PDSCH including second downlink data, wherein the first TPC field of the first PDCCH includes control information for controlling transmission power of a physical uplink control channel, PUCCH, resource on an uplink component band set in the terminal apparatus, and the second TPC field of the second PDCCH includes control information for setting the PUCCH resource in the uplink component band, wherein the first component carrier is associated with the uplink component band set in the terminal apparatus and the second component carrier is a component carrier other than the component carrier associated with the uplink component band set in the terminal apparatus; the receiving section is configured to extract the control information allocated to the TPC field of a received PDCCH and output the extracted control information as control information for controlling transmission power of the PUCCH resource or as control information for setting the PUCCH resource in the uplink component band based on whether the respective PDCCH is allocated to a component carrier associated with the uplink component band set in the terminal apparatus or not; a mapping section configured to determine the PUCCH resource on the uplink component band associated with the first component carrier using the control information extracted from the second TPC field, the PUCCH resource being used for transmission of a response signal for the first downlink data and the second downlink data received on the first component carrier and the second component carrier, and to map the response signal to the determined PUCCH resource on the uplink component band associated with the first component carrier. a receiving section configured to receive a first physical downlink control channel, PDCCH, and a first physical downlink shared channel, PDSCH, on a first component carrier and to receive a second PDCCH and a second PDSCH on a second component carrier, the first PDCCH including a first transmission power control, TPC, field, the first PDSCH including first downlink data, the second PDCCH including a second TPC field, and the second PDSCH including second downlink data, wherein the first TPC field of the first PDCCH includes control information for controlling transmission power of a physical uplink control channel, PUCCH, resource on an uplink component band set in the terminal apparatus, and the second TPC field of the second PDCCH includes control information for setting the PUCCH resource in the uplink component band, wherein the first component carrier is associated with the uplink component band set in the terminal apparatus and the second component carrier is a component carrier other than the component carrier associated with the uplink component band set in the terminal apparatus; the receiving section is configured to extract the control information allocated to the TPC field of a received PDCCH and output the extracted control information as control information for controlling transmission power of the PUCCH resource or as control information for setting the PUCCH resource in the uplink component band based on whether the respective PDCCH is allocated to a component carrier associated with the uplink component band set in the terminal apparatus or not; a mapping section configured to determine the PUCCH resource on the uplink component band associated with the first component carrier using the control information extracted from the second TPC field, the PUCCH resource being used for transmission of a response signal for the first downlink data and the second downlink data received on the first component carrier and the second component carrier, and to map the response signal to the determined PUCCH resource on the uplink component band associated with the first component carrier.