说明：  FIR 滤波器也称为有限冲击响应滤波器，它用当前和过去输入样值的加权和来形成它的输出, 如下所的前馈差分方程所描述的。 FIR 滤波器又称为移动均值滤波器, 因为任何时间点的输出均依赖于包含有最新的 M个输入样值的一个窗。由于它的响应只依赖于有限个输入, FIR 滤波器对一个离散事件冲激有一个有限长非零响应, 即一个 M阶 FIR 滤波器对一个冲激的响应在 M个时钟周期之后为零。
(FIR filter, also known as finite impulse response filter, it uses current and past input samples to form the weighted sum of the value of its output, as the feed-forward differential equations described. FIR filter, also known as moving average filters, because any point in time are dependent on the output of M contains the latest input sample values a window. Because of its response depends only on a limited input, FIR filter to a discrete event there is a finite non-zero impulse response, that is, an M-order FIR filter to an impulse response in the M clock cycles after the zero.)