论频率分辨率与频率步长的关系以及数据添零对频谱的影响

在阐明了“频率分辨率与频率步长既不是一个概念，在数值上也并非始终相等”的基础上，论证和对比了数据添零（补零与插零）、提高采样率与数据延推（延长与外推）等，共两类五种缩小频率步长的方法对频谱包络及分辨率的影响，得出了“添零不改变频谱包络，根本不能提高分辨率，只能单纯缩小频率步长、密化谱线”，“补零使谱线插值式密化对提高谱分析精度也有一定好处”，“插零使谱线周期性密化，可方便地实现基带带宽压缩和多采样

A Systematic Discussion of Difference in Concept between Frequency Resolution and Frequency Interval

In many periodiCals and books, it is quite common to find that frequency resolution andfrequency intervat are incorrectly taken to be one and the same concept. In some particularcases, the two concepts are correctly treated as being different. We in this paper present asystematiC investigation of the difference between the two concepts.We discuss systematically the effects of adding zeroes to data (including supplying zeroes and inserting zeroes) and increasing data information (Including data lengthening, dataextension, and increased sampling rate) on the envelope of frequency spectrum and frequencyresolution.One example of our work is presented in Figs. 2,3, and 4. Figs. 2 and 3 are spectrum diagrams for supplying zeroes and for inserting zeroes. Fig. 4 shows effect of increasing datainformation on spectrum diagram.On the basis of theoretical discussion and examples similar to the one presented in Figs.2,3, and 4, we draw the following two conclusions:(1) Adding zeroes to data does not alter the envelope of frequency spectrum i it is absolutely of no use in improving resolution 4 it is just beneficial in that spectrum interval is madesmaller and thus spectrum lines become dense.(2) The only way to improve resolution is through increasing data information (including data lengthening, data extension, and increased sampling rate).