中文说明：
本设计要求学生以MATLAB作为设计工具，利用脉冲响应不变法或双线性变换法的一种或两种进行设计IIR数字低通滤波器，并利用MATLAB中的仿真工具进行系统仿真。将利用上述两种不同的方法设计的FIR滤波器的结果进行比较，分析各设计方法的特点及优缺点。
English Description：
This design requires students to use MATLAB as a design tool to design IIR digital low-pass filter by using one or two of impulse response invariance method or bilinear transformation method, and carry out system simulation by using the simulation tools in MATLAB. The results of FIR filters designed by the above two different methods are compared, and the characteristics, advantages and disadvantages of each design method are analyzed.