多个低阶滤波器实现高阶递归数字滤波器的方法

Method of realizing high order recursive digital filter using low step filters

研究一种实现高阶递归数字滤波器的方法，其特点是将高阶滤波器分解成一组并联的低阶滤波器，其设计步骤为：首先选择低阶滤波器的数量和阶数，然后给低阶滤波器分配极点，并将滤波器的传递函数分解成低阶滤波器的并联，最后综合每一个低阶滤波器． 采用该方法设计的高阶数字滤波器与其它滤波器相比能够减少量化噪声， 增大量化的允许偏差．

A method of realizing high order recursive digital filter using low step filters is approached, the characteristic is partitioning the overall filter into a set of parallel subfilters. The designing step is as follows: at first deciding on the number of subfilters and their orders, then allocating pole for any given subfilter, and partitioning the filter into subfilters,at last synthesising the subfilters. The high order recursive digital filter designed by this method has reduced more quantisation noise and improved more tolerance to quantisation than their classical counterparts. Therefore this method is particularly useful when the filter order is greater than 50.