Customized architecture for implementing configurable FFT on FPGA

Fourier transform algorithm has encompassed diverse fields of engineering including specialized fields like radars, communications and image processing systems. Therefore there have been continual efforts to improve the efficiency of FFT implementation in real time systems and other hardware. To reduce design time and time to market, FPGA vendors have developed IP cores which can be readily used in our applications. But these IP core designs though efficient are highly abstract and do not provide the designer to modify them according to his requirement which leads to inefficient design realization. Vendor provided IP cores do not give access to FFT kernel matrix thus restricting the configurability and efficiency of using them. In this paper we have designed a customized architecture to perform FFT with access to twiddle factors for improved configurability. The designed architecture is further modified to perform variable point FFT targeted for application in multirate systems. The architecture designed is generic and can be implemented on any vendor platform.