中文说明：xn = [1,1,1,1] 试用 < 跨风格 ="字体-大小： 12.0pt ； 字体系列：""> MATLAB编写程序，计算该序列的离散付里叶变换及逆离散付里叶变换。2、取一个周期的正弦信号，作8点采样，求它的连续频谱。然后对该信号进行N个周期延拓，再求它的连续频谱。把N无限增大，比较分析其结果。3、一个三阶滤波器由以下的差分方程描述： y(n) = 0.0211x(n)+0.0443x(n-1) + 0.044x(n-2)+0.0181x(n-3) + 1.76y(n-1)-1.272y(n-2)+0.3181y(n-3) 画出此滤波器的副值和相位响应并说明它是一个什么样的滤波器。
English Description：
Xn = [1,1,1,1] trial < span style = "font-size: 12.0pt; font-family:" "> MATLAB programming, calculating the sequence of discrete Fourier transform and the inverse discrete Fourier transform. 2, take a cycle of sinusoidal signals, 8 point sampling, seek a continuous spectrum. And the use of the n-cycle continuation, then ask one of the continuous spectrum. Infinite increasing n, comparative analysis of its results.3, a third-order filter is described by the following difference equation: y (n) = 0.0211x (n) +0.0443x (n-1) + 0.044x (n-2) +0.0181x (n-3) + 1.76y (n-1) -1.272y (n-2) +0.3181y (n-3) draws this vice and phase response of the filter and note that it is a kind of filter.