用MATLAB函数fir1设计一个具有如下指标的线性相位FIR带通滤波器：阻带截止频率为0.55pi 和0.85pi，通带截止频率为0.65pi和 0.75pi，最大通带衰减为0.2dB，最小阻带衰减为42dB。分别利用下面的窗函数来设计滤波器：汉宁窗、汉明窗、布莱克曼窗。对于每种情况，给出其冲激响应系数并画出设计的滤波器的幅频响应。-Designed with a MATLAB function with the following indicators fir1 linear phase FIR band-pass filter: stopband cutoff frequency for the 0.55pi and 0.85pi, passband cutoff frequency of 0.65pi and 0.75pi, maximum passband attenuation is 0.2dB, minimum stopband attenuation of 42dB. Window functions were used to design the following filter: Hanning, Hamming window, Blackman window. For each case, given its impulse response filter coefficients and draw the design magnitude response.