A radio communication system which comprises a radio base station apparatus and a user terminal configured to perform radio communication with the radio base station apparatus by time division duplexing, TDD, and which achieves broadbandization by carrier aggregation, CA, wherein: a) the radio base station apparatus comprises: a1 a generating section configured to generate a downlink control channel signal containing downlink control information including carrier indicator field, CIF, information; and a2) a transmission section configured to transmit the downlink control channel signal to the user terminal; and b) the user terminal comprises: b1) a receiving section configured to receive the downlink control channel signal; and b2) a signal processing section configured to execute signal processing with respect to a downlink signal in accordance with the downlink control information, c) wherein the transmission section of the radio base station notifies the user terminal of information, as the carrier indicator field, CIF, information that associates a carrier index and the number of victim subframes to be scheduled, the victim subframes being subframes that cannot be scheduled by a control channel, PDCCH, in a present subframe or a link subframe, and characterized in that the victim subframes are scheduled by a super subframe, and wherein d) a separate retransmission control, HARQ, process is applied to scheduling information of each victim subframe. a) the radio base station apparatus comprises: a1 a generating section configured to generate a downlink control channel signal containing downlink control information including carrier indicator field, CIF, information; and a2) a transmission section configured to transmit the downlink control channel signal to the user terminal; and a1 a generating section configured to generate a downlink control channel signal containing downlink control information including carrier indicator field, CIF, information; and a2) a transmission section configured to transmit the downlink control channel signal to the user terminal; and b) the user terminal comprises: b1) a receiving section configured to receive the downlink control channel signal; and b2) a signal processing section configured to execute signal processing with respect to a downlink signal in accordance with the downlink control information, b1) a receiving section configured to receive the downlink control channel signal; and b2) a signal processing section configured to execute signal processing with respect to a downlink signal in accordance with the downlink control information, c) wherein the transmission section of the radio base station notifies the user terminal of information, as the carrier indicator field, CIF, information that associates a carrier index and the number of victim subframes to be scheduled, the victim subframes being subframes that cannot be scheduled by a control channel, PDCCH, in a present subframe or a link subframe, and characterized in that the victim subframes are scheduled by a super subframe, and wherein d) a separate retransmission control, HARQ, process is applied to scheduling information of each victim subframe.