Provided is a cyclic shift sequence generation method which can prevent coming of an interference wave into a desired wave detection window even if a cyclic shift sequence has a high mutual correlation in different bandwidths, thereby improving a channel estimation accuracy in a base station. In this method, a cyclic shift sequence number to be allocated to a cell is decided in advance. Moreover, when the cyclic shift amount between cyclic shift sequences allocated in cells is Δ1 and the cyclic shift amount of the cyclic shift sequences allocated between the cells is Δ2, Δ1 and Δ2 are made different when generating a cyclic shift sequence.