DFT分配 [英] Assignment for DFT

问题描述

需要确定模拟信号的DFT
x(t)= 25 cos(10PIt)cos(400PIt).
(a)
找到信号的奈奎斯特速率.

410Hz

(b)
如果所需的频率分辨率为5Hz，记录(信号)长度是多少?

0.2秒

(c)
如果使用(a)部分的奈奎斯特速率和(b)部分中的记录长度，请查找DFT中将包含的点数.

82

(d)
使用MATLAB函数fft查找并绘制DFT X(k).将频率刻度(以赫兹为单位)添加到图中.


我不确定如何编写最后一部分的脚本

解决方案

当老师告诉您如何做时，您是否在课堂上没有注意? blockquote>

It is desired to determine the DFT of the analogue signal
x(t) = 25 cos(10PIt)cos(400PIt).
(a)
Find the Nyquist rate of the signal.

410Hz

(b)
What is the record (signal) length if the desired frequency resolution is 5Hz?

0.2s

(c)
If the Nyquist rate from part (a) and the record length found in part (b) are used, find the number of points that will be contained in the DFT.

82

(d)
Use the MATLAB function fft to find and plot the DFT X(k). Add the frequency scale (in hertz) to the diagram.


I not sure how to write the script for the last part

解决方案

Weren''t you paying attention in class when the instructor told you how to do it?

这篇关于DFT分配的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！