这个程序是MATLAB的程序，它能够实现中心频率是4000Hz的带通滤波器的功能，在4000Hz的信号上面加了噪声信号，通过滤波器滤除杂波-This program is MATLAB program that enables the center frequency is 4000Hz band-pass filter function in the 4000Hz signal above the noise signal added, filtered through the clutter