Fast Foourier transform processor and method thereof

The invention provides a fast Foourier transform processor and a method thereof. The fast Foourier transform processor carries out multilevel mixed-radix butterfly computation on an N point sequence. The multilevel mixed-radix butterfly computation orderly comprises Alpha2 level radix-2 butterfly computation, Alpha3 level radix-3 butterfly computation, Alpha4 level radix-4 butterfly computation and Alpha5 level radix-4 butterfly computation, wherein Alpha2 and Alpha5 are both integers larger than or equal to 0, Alpha3 and Alpha4 are both integers larger than 0, and the input data of each level of butterfly computation is the computation result of the previous level of butterfly computation. The fast Foourier transform processor satisfies the requirement of an LTE system and realizes the DFT of accurate point-number sequence in the LTE system.