FPGA implementation of Radix-2 FFT processor based on Radix-4 CORDIC

Abstract

Fast Fourier Transforms are the algorithms for the effective computation of the Discrete Fourier Transforms. This paper involves the design and implementation of FFT using CORDIC algorithm, with VHDL on FPGA. CORDIC-Co-ordinate Rotation Digital Computer is an iterative algorithm capable of computing wide range of functions such as trigonometric, hyperbolic, linear and logarithmic using Shift and Add approach. This amount of SHIFT and ADD is carried out by performing vector rotations by arbitrary angles (which are pre-computed). Radix 4 CORDIC algorithm is designed as it is far more efficient than Radix 2 CORDIC in terms of latency. This is used in radix 2 FFT algorithm for generating twiddle factors. These twiddle factors are required for generating the FFT.