说明：   1.题目：数字滤波器的设计与应用 2.设计要求：利用 Matlab 软件,以复合信号分离为例,对 “数字信号处理” 课程中 的谱分析 、数字滤波器设计和信号滤波这三个过程进行了仿真实现,给出了仿真结果。 3.具体步骤： （1）构造原始信号s(t) （2）画出s(t)的频谱 （3）设计ellipse数字滤波器(IIR)，包括低通，带通，带通，并显示幅频特性 （4）用得到的滤波器进行滤波，分离出三路信号，观察时域波形和幅频特性 （5）用三路信号s1,s2,s3尝试重新合成原始信号 4.问题：为什么重新合成的信号和原信号不相等呢？谁能解释一下？谢谢,QQ:664519036
( 1. Title: Digital Filter Design and Application 2. Design requirements: use of Matlab software to composite signal separation, for example, on "Digital Signal Processing" course Of the spectral analysis, digital filter design and signal filtering process carried out three Simulation, the simulation results. 3. Concrete steps: (1) construct the original signal s (t) (2) Draw s (t) of the spectrum (3) design ellipse digital filter (IIR), including low pass, band pass, band pass, and shows amplitude-frequency characteristics (4) filtering with a filter obtained by the isolation of three signals, observed time-domain waveform and frequency characteristics (5) with a three-way signal s1, s2, s3 try to re-synthesis of the original signal 4. Question: Why is re-synthesized signal and the original signal is not equal to it? Who can explain? Thank you, QQ: 664519036)