FPGA实现流水线结构的FFT处理器

FPGA Implementation of Pipelined FFT

针对高速实时信号处理的要求,介绍了用现场可编程逻辑阵列(FPGA)实现的一种流水线结构的FFT处理器方案。该FFT处理器能够对信号进行实时频谱分析,最高工作频率达到75MHz。通过对采样数据进行加窗处理来减少了频谱泄漏产生的误差。为了提高FFT工作频率和节省FPGA资源,采用了由1024点复数FFT计算2048点实数FFT的算法。此外还介绍了一种计算复数模值的近似算法。

A pipelined FFT processor designed for fast and real-time requirements with FPGA is introduced. This FFT processor can be used to real-time frequency analysis and its working frequency can reach to 75 MHz. The leakage error is reduced through multiply the sampled signal by a weighting window. In order to improve FFT's working frequency and economize FPGA resources, an algorithm of 1024-point complex to compute 2048-point real data is adopted. In addition, an approximate algorithm to compute module value of complex number is introduced.