Method for allocating sequence having various resource block length, and method for grouping sequence for the same

A method for allocating sequences having various resource block lengths, and a sequence grouping method for the same are provided to prevent degradation of channel estimation performance due to high inter-cell interference. A method for allocating sequences having various resource block lengths(1RB,2RB,3RB) in a multi-cell environment includes the steps of: grouping the sequences which have inter-cell interference of more than a predetermined interference threshold, into the same group among the sequences having the various resource block lengths; and allocating the grouped sequences to the same sequence allocation unit region.