SFF—The Single-Stream FPGA-Optimized Feedforward FFT Hardware Architecture

In this paper, a fast Fourier transform (FFT) hardware architecture optimized for field-programmable gate-arrays (FPGAs) is proposed. We refer to this as the single-stream FPGA-optimized feedforward (SFF) architecture. By using a stage that trades adders for shift registers as compared with the single-path delay feedback (SDF) architecture the efficient implementation of short shift registers in Xilinx FPGAs can be exploited. Moreover, this stage can be combined with ordinary or optimized SDF stages such that adders are only traded for shift registers when beneficial. The resulting structures are well-suited for FPGA implementation, especially when efficient implementation of short shift registers is available. This holds for at least contemporary Xilinx FPGAs. The results show that the proposed architectures improve on the current state of the art.