CZT和ZFFT频谱细化性能分析及FPGA实现

Performance Analysis for CZT and ZFFT Spectrum Zoom and Its FPGA Realization

摘要:

快速傅里叶变换在信号的频谱分析中应用广泛,而在工程实际中往往只对信号频谱中一段区间感兴趣,需要对频谱进行细化分析；常用的频谱细化方法有线性调频Z变换(Chirp-Z Transform, CZT)算法和基于复调制的细化(Zoom-FFT, ZFFT)算法,在给出了两种频谱细化方法的计算流程后,通过MATLAB仿真说明两种算法都能提高信号频率的测量精度,最后给出了这两种算法在FPGA具体工程实现中的实现步骤。

Abstract:

Fast Fourier Transform is widely used in the signal spectrum analysis. However, it usually gets interesting in a part of the whole signal spectrum in engineering, so it needs spectrum zoom analysis. It is the common method for spectrum zoom which including complex modulation Zoom-FFT (ZFFT) and Chirp-Z Transform (CZT). After the calculating methods of two kinds spectrum zoom are given, both ZFFT and CZT can improve the measurement accuracy by simulation in MATLAB. Lastly, this paper gives the realization steps of the two methods in FPGA engineering.