一种基-2 FFT算法的误差分析方法

摘要

FFT Algorithm plays an important role in engineering applications.The requirement of precision and resources of FFT’s hardware structure become more and more important.In this paper,whole calculating process of radix-2 FFT was analyzed,and a developed method to value the error of radix-2 FFT was proposed. Taking radix-2 FFT of 16 points as an ex-ample,we analyzed the source and the transaction of errors during whole calculating.Finally,the signal-noise ratio can be cal-culated by means of the error analysis method, which is equal to 25623 ×22b.%FFT算法在工程领域有着大量的应用，精度要求也越来越高，对系统的硬件资源占用也越来越大，对FFT算法进行误差分析，精确定位每级FFT舍入的原则可更高效地指导开展FFT硬件架构设计。以基-2 FFT算法为例，详细分析了基-2 FFT算法的实现结构及误差产生来源，提出了一种基-2 FFT的误差分析模型，并以16点基-2 FFT为例，采用该误差分析方法进行误差分析，得到信噪比25623×22b(b为第1级输入位宽)。