基于MATLAB的高性能半带滤波器设计

在数字滤波器的设计中，为了能够有效地进行抽取滤波，往往采用多级抽取的方法。文中引入一种半带FIR（有限冲激响应）滤波器来实现多级抽取。半带滤波器是一种特殊的低通FIR数字滤波器，它的通带和阻带关于二分之一Nyquist频率对称，因而有近一半的滤波器系数为0，所以用它来实现数字滤波可以大幅度地减少运算量，有利于滤波器的实时实现。半带FIR滤波器主要应用于多速率系统中，可以提高系统的效率。剖析了半带FIR滤波器的原理、性质及实现的方法，给出了基于MATLAB和QuartusⅡ联合的半带FIR滤波器的设计仿真过程，并对结果进行了分析。

High-performance Half-band Filter Designing Based on MATLAB

Multi-stage extraction method is often used in digital filter design for efficient implementation of digital decimation filtering. In this paper, a half - band Finite Impulse Response （ FIR ） filter is introduced to achieve multi-level extraction. The half-band filter is a special FIR low-pass digital filter, with its pass-band and stop-band symmetric about the half of the Nyquist frequency, and almost half coefficients of the filter are zeros. This reduces computation of filtering significantly when it is used for decimation and this makes on time fihering achievable. The half-band filter is mainly used in muhi-rate system, which can improve system efficiency. In this paper, the theory, characteristics and implementation of the half-band FIR filter are analyzed, the design process of the filter based on combination of MATLAB and Quartus 11 are given, and the results are also analyzed.