Patent ID: 8509285

Claim:
A base station apparatus comprising: a transmitting unit configured to transmit data to a radio communication apparatus, and transmit, to the radio communication apparatus, control information on one or a plurality of control channel elements (CCEs) with consecutive CCE number(s), CCEs being numbered sequentially from one; and a receiving unit configured to receive a response signal corresponding to the data, the response signal being transmitted from the radio communication apparatus, wherein: the response signal is spread 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 with an orthogonal sequence that is determined among a plurality of orthogonal sequences from the index; and 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.