Radix-8 FFT processor design based on FPGA

A design of 4096-point radix-8 fast Fourier transform (FFT) is implemented on Field Programming Gate Array (FPGA). The butterfly element, twiddle factor generator, I/O unit have been analyzed and optimized. The processor works in a pipeline style in order to improve the operation speed and reduce the occupancy of the FPGA internal resources. It succeeded in passing the simulation verification and test. The result was compared with Matlab fixed-point model. Under a clock of 100MHz, the processor takes 20.48µs to finish a 4096-point radix-8 FFT, which meets the requirement of high speed digital signal processing.