基于MATLAB的FIR数字滤波器设计

加深对数字滤波器的常用指标和设计过程的理解。

FIR滤波器实现一般采用窗函数法和等纹波设计法。窗函数法还包含两个分支，一种是用公式先手动算出N值和其他对应得窗函数参数值，再代入窗函数和fir1实现，一种是用函数*rord估算出N和相应参数再用fir1实现。不过要注意*rord会低估或高估阶次n，可能会使滤波器达不到指定的性能，这时应稍微增加或降低阶次。如果截止频率在0或Nyquist频率附近，或者设定的dev值较大，则得不到正确结果-MATLAB-based FIR digital filter design of the digital filter to enhance common understanding of targets and the design process. FIR filters achieve the commonly used window function method and design method such as ripple. Window function method also includes two branches, one is to use the formula to manually calculate the first N values and other parameters of the corresponding window function value was then substituted into the window functions and fir1 achieved, one is to use a function* rord estimate the parameters of N and the corresponding re- achieved with fir1. But pay attention to* rord will underestimate or overestimate the order sub-n, may make up less than a specified filter performance, this time to be a slight increase or decrease order times. If the cut-off frequency of 0 or near the Nyquist frequency, or the value of a larger dev set, then the result is not correct