It is an object to provide a sequence allocating method that, while maintaining the number of Zadoff-Chu sequences to compose a sequence group, is configured to make it possible to reduce correlations between different sequential groups and between same sequential groups. This method comprises the steps of setting a standard sequence with a standard sequence length (Nb) and a standard sequence number (rb) in a step (ST101), setting a threshold values (Xth1(m)) and (Xth2(m)) in accordance with an RB number (m) in a step (ST103), setting a sequence length (N) corresponding to RB number (m) in a step (ST104), judging whether ¦r/N−rb/Nb¦=Xth1(m) is satisfied in a step (ST106), judging whether ¦r/N−rb/Nb¦=Xth2(m) is satisfied in a step (ST107), including Zadoff-Chu sequences with a sequence number (r) and a sequence length (N) in a sequence group (rb) in a step (ST108); if both judgments are positive, and allocating the sequence group (rb) to the same cell in a step (ST113).