Low-power Radix-4 FFT Structure for OFDM using Distributed Arithmetic

In this paper, an efficient butterfly structure for Radix-4 FFT algorithm using DA(Distributed Arithmetic) is proposed. It is shown that DA can be efficiently used in twiddle factor calculation of the Radix-4 FFT algorithm. The Verilog-HDL coding results for the proposed DA butterfly structure show cell area reduction comparison with those of the conventional multiplier butterfly structure. furthermore, the 64-point Radix-4 pipeline structure using the proposed butterfly and delay commutators is compared with other conventional structures. Implementation coding results show cell area reduction. Due to its efficient processing scheme, the proposed FFT structure can be widely used in large size of FFT like OFDM Modem.