Patent ID: 8514908

Claim:
A radio communication apparatus comprising: a receiving unit configured to receive control information transmitted on one or a plurality of control channel elements (CCEs) with consecutive CCE number(s), CCEs being numbered sequentially from one; and a spreading unit configured to first-spread a response signal with a sequence defined by a cyclic shift value that is determined among a plurality of cyclic shift values from an index of physical uplink control channel (PUCCH), which is associated with a first CCE number of said one or a plurality of CCEs, and configured to second-spread the first-spread response signal with an orthogonal sequence that is determined among a plurality of orthogonal sequences from the index; wherein, one of cyclic shift values used for an orthogonal sequence is determined from an index of the PUCCH, which is associated with an odd CCE number, and another one of the cyclic shift values used for the same orthogonal sequence is determined from an index of the PUCCH, which is associated with an even CCE number, and the first CCE number is restricted to be an odd number when the control information is transmitted on the plurality of CCEs.