说明：  通过对IIR数字滤波器算法的研究,得出IIR数字滤波器的设计方案.经过仿真实验表明该滤波器能够滤除信号中的噪声,滤波效果良好
(Of IIR digital filter algorithm, derived IIR digital filter design. After simulation results show that the filter can filter out the noise signal, filter results)