复调制ZFFT的TMS320C25实现

介绍了用ＴＭＳ３２０Ｃ２５数字信号处理器实现复调制ＺｏｏｍＦＦＴ（ＺＦＦＴ）频率细化技术，在所举的例子中，用１０２４复数点选带ＦＦＴ获得通常８１９２复数点基带ＦＦＴ的频率分辨力。实验结果表明，此种频率细化方法特别适用于不能同时处理Ｎ点，而又要求Ｎ点ＦＦＴ频率分辨力的频谱分析场合，文中给出了几种提高Ｃ２５ＦＦＴ运算速度的方法，使１０２４复数点ＦＦＴ的运算时间减少到１２．６ｍｓ，可供工程应用参考。

Implementation of Zoom FFT Using Complex Modulation with TMS320C25

The Zoom FFT(ZFFT) using complex modulation is a technique to improve the frequency resolution. Its implementation with TMS320C25 is presented in this paper. The frequency resolution of the ZFFT with 1024 sample points (band-selected FFT) is the same as that of the directed FFT with 8192 sample points. The experimental results show that this technique of minute analysis in the frequency domain is particularly suitable for the analyzer which cannot handle N points simultaneously but calls for the frequency resolution'of N points FFT. In this paper some methods that accelerate the operation speed of C25 FFT are proPDsed,which can reduce the operating time of the FFT with 1024 complex sample points to 12.6ms and serve as a reference in engineering.