Provided are a communication apparatus and a method for receiving a response signal transmitted from a terminal configured with one or more downlink component carriers. The communication apparatus includes a transmitting section and a receiving section. The transmitting section is configured to transmit, to the terminal, downlink assignment information indicating one or more resources for downlink data, each of the one or more resources being assigned to one of the one or more downlink component carrier(s), and configured to transmit the downlink data to the terminal. The receiving section is configured to receive one or more response signals for the downlink data, which are transmitted from the terminal. The terminal makes the phase points of the response signals different in accordance with a number of downlink data which has been successively received.