Patent ID: 8369382

Claim:
A base station for receiving an acknowledgement or negative acknowledgement (ACK/NACK) signal, comprising: a transmitting unit configured to transmit a control signal using one or a plurality of Control Channel Elements (CCE(s)); and 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 on an axis of rotation, and wherein the orthogonal sequence has a sequence index corresponding to a Physical Uplink Control Channel (PUCCH) index associated with a first CCE number of said one or a plurality of CCE(s) and the cyclic shift corresponds to the PUCCH index; wherein, in a case where said PUCCH index is in a first PUCCH index group, the ACK/NACK signal is multiplied by the same one of the first value or the second value for both communication in a first slot and communication in a second slot, and in a case where said PUCCH index is in a second PUCCH index group, the ACK/NACK signal is multiplied by different ones of the first value and the second value, respectively, for communication in the first slot and communication in the second slot.