用在频谱细化中Chirp-Z变换的特性分析  

Character Analyses of the Chirp-Z Transformation Used in the Spectrum Zooming

作　　者：冯志华[1] 刘永斌[1] 张健[1] 

机构地区：[1]中国科学技术大学精密机械与精密仪器系

出　　处：《信号处理》2006年第5期741-745,共5页Journal of Signal Processing

摘　　要：通过理论分析与仿真,证实了Chirp Z变换对单一频率信号进行细化方面的有效性,可以通过求极值点的位置得到较为精确的频率值；而对于多频率信号而言,如果它们相距较远,则影响不大,但在较近的时候,不但对它们的区分受到fs/N这个值限制,而且对频率的读数也将产生一定的误差,这个误差可达分辨率的50%以上。因此,利用Chirp Z变换来区分两个频率相近的信号不但能力十分有限,而且也不精确。By theoretical analyzing and simulation, the effectiveness of the chirp-Z transformation used in the spectrum zooming analyses has been proved, but the limitation of this method is also point out, especially the frequency＇ s discrimination will be limited by the fs/N also. Although it gives us a way to get a rather precision value of a single frequency ,it can not discriminate two close frequencies effectively because the power leakage. The readout of the frequencies will vary from the actual values largely, and the error can be as high as 50% of the discrimination.

关 键 词：傅立叶变换 Z变换 频谱分析 信号分析 频谱细化 

分 类 号：TN957.51[电子电信—信号与信息处理]