信号截短对频谱分辨率的影响  

Influence of Signal-cutting to the Resolution of Spectrum

作　　者：张小虹[1] 

机构地区：[1]解放军理工大学理学院,江苏南京211101

出　　处：《电气电子教学学报》2005年第1期21-24,94,共5页Journal of Electrical and Electronic Education

摘　　要：频谱分辨率是数字信号处理教学和工程应用中经常遇到的问题。只有抓住影响频谱分辨率诸因素中的主要矛盾 ,才能在实际中用较少的硬件和尽可能短的时间资源实现预期的设计目的。为此 ,本文以理论和实际相结合 ,引入了“高密度频谱”和“高分辨率频谱”的概念 ,并阐述了信号截短对频谱分辨率的影响。通过分析可知 ,频率分辨率既与待处理的信号之间的最小相对频率 Δω′有关 ,又与截短函数长度 Np有关。只有当 Np=2π/Δω′min时 ,才可确保通过 DFResolution of spectrum is the common problem occurring in teaching of digital signal processing and engineering application. Only focusing on the key points which influence the factors of resolution of spectrum, can the design purpose be realized in practice by using less hardware and less time. By combining theory with practice, this paper introduces the concepts of 'high-density spectrum' and 'high resolution spectrum', and expounds the influence signal-cutting to the resolution of spectrum. The conclusion is that the resolution of spectrum is not only related to the smallest relative frequency Δω′ among the pending signals, but also related to the length of signal-cutting, and only with N p=2π/Δω ′ min , the frequency of the original signals can be reconstructed by DFT.

关 键 词：截短 频率分辨率 高密度频谱 高分辨率频谱 

分 类 号：TN911.6[电子电信—通信与信息系统]