FIR滤波器：自定滤波器的类型（低通，高通或带通）、设计指标（通带截止频率、通带波纹、阻带截止频率、阻带衰减）

1、根据指标选择合适的窗函数，用窗口设计法设计符合指标的FIR滤波器；并验证其性能是否满足预定指标。

-FIR filters: Custom filter types (low pass, high pass or band-pass), design specifications (passband cutoff frequency, passband ripple, stopband cutoff frequency, stopband attenuation) 1, according to indicators choose the right window function, using the window design method of FIR filter designed to meet the targets　and verify that its performance meets the set targets.