Design of an Area-Efficient Various N-point Support radix-2/22 FFT using Modified Butterfly Units

Abstract

Fast Fourier Transform (FFT) acts as an element in the high-speed signal processing application, which involves the following subsequent operations, namely complex addition, complex subtraction and complex multiplication. Due to the complex multiplication operation, the FFT structures lead to more hardware demand. Hence, this work introduces an area-efficient various N-point support radix-2 and radix-22 FFT structure by using proposed modified butterfly units and radix-2/22 butterfly unit. The proposed modified butterfly units are used to reduce the number of complex multipliers effectively. For this reason, it is using for certain conditions in FFT design instead of existing radix-2/22 butterfly unit. Further, the proposed design supported to perform various size of FFT in a single architecture without increasing the extra element demand. Moreover, the proposed FFT structure designed and implemented using a Xilinx Virtex-6 Field-Programmable Gate Array (FPGA) device (6vcx75tff484-2) and Cadence tool with 45nm CMOS technology. The implementation results demonstrate that the proposed N-point (N=16, 32 and 64) DIF-FFT design attains the less hardware complexity when compared with existing multi-mode FFT design. Then the proposed area-efficient 16-point, 32-point and 64-point radix-2 FFT architectures reduce the total area by 20.99%, 11% and 4.9% respectively. As well, the proposed area-efficient 16-point, 32-point and 64-point radix-22 FFT architectures reduce the total area by 32%, 19% and 11% respectively.

Radix-22 Algorithm for the Odd New Mersenne Number Transform (ONMNT)

“…The radix-2 2 algorithm can, therefore, be implemented for any value of N that is a power of 2. Moreover, significant memory savings have been achieved using this algorithm [15]. Therefore, multiple efficient implementations of the radix-2 2 FFT algorithm have been proposed for application-specific integrated circuits (ASIC) [16] and field-programmable gate arrays (FPGA) [16][17][18], primarily in the field of wireless communication.…”