A base station is provided for receiving an acknowledgement or negative acknowledgement (ACK/NACK) signal, including a transmitting unit configured to transmit a control signal using one or a plurality of control channel elements (CCE(s)). The base station also includes a receiving unit configured to receive an ACK/NACK signal, the ACK/NACK signal being multiplied by an orthogonal sequence, by a sequence defined by a cyclic shift, and by either a first value or a second value, wherein the first value rotates a constellation of the ACK/NACK signal by 0 degrees and the second value rotates the constellation of the ACK/NACK signal by N degrees, which is different from 0 degrees.