A radio communication device capable of randomizing both inter-cell interference and intra-cell interference. In this device, a spreading section (214) primarily spreads a response signal in a ZAC sequence set by a control unit (209). A spreading section (217) secondarily spreads the primarily spread response signal in a block-wise spreading code sequence set by the control unit (209). The control unit (209) controls the cyclic shift amount of the ZAC sequence used for the primary spreading in the spreading section (214) and the block-wise spreading code sequence used for the secondary spreading in the spreading section (217) according to a set hopping pattern. The hopping pattern set by the control unit (209) is made up of two hierarchies. An LB-based hopping pattern different for each cell is defined in the first hierarchy in order to randomize the inter-cell interference. A hopping pattern different for each mobile station is defined in the second hierarchy in order to randomize the intra-cell interference.