High efficient and real-time realization of Zoom FFT based on FPGA

The paper proposed a novel method for implementing Zoom FFT with field programmable gate array (FPGA) for high performance spectral analysis. A scheme of multistage decimation Zoom FFT was given by using the parallel pipelining processing character of FPGA to reduce the computational complexity of traditional Zoom FFT. Meanwhile, a polyphase filter suitable for high decimation-times was designed, and then the polyphase filter and an efficient cascaded integrator-comb (CIC) filter were applied into every stage of decimation structure. Simulation result indicates that compared with single-stage decimation structure, our method´s error of amplitude analysis can be lower than 1dB for 200 of decimation-times, so that maximum Zoom-times and precision can be improved. The method can reduce FPGA resources consuming and achieve high processing speed.