Multiplierless reconfigurable processing element for mixed radix-2/3/4/5 FFTs

This paper presents area-efficient building blocks for computing fast Fourier transform (FFT): multiplierless processing elements to be used for computing of radix-3 and radix-5 butterflies and reconfigurable processing element supporting mixed radix-2/3/4/5 FFT algorithms. The proposed processing elements are based on Wingorad Fourier transform algorithm. However, multiplication is performed by constant multiplier instead of a general complex-valued multiplier. The proposed process elements have potential use in both pipelined and memory based FFT architectures, where the non-power-of-two sizes are required. The results show that the proposed multiplierless processing elements reduce the significant hardware cost in terms of adders.