A communication apparatus in a mobile communication system includes a first control information generation unit configured to generate first control information including retransmission information on a previously received data channel, a second control information generation unit configured to generate second control information including scheduling information on radio resources and a transmission signal generation unit configured to generate a transmission signal including a lower layer control channel including at least one of the first control information and the second control information. The transmission signal generation unit generates the transmission signal to transmit the first control information in any of subframes arriving at a first cycle and to transmit the second control information in any of subframes arriving at a second cycle longer than the first cycle.