IIR滤波器结构分析和Blackfin DSP定点优化实现

Structure analyse in IIR filter and fixed- point optimization on Blackfin DSP

ADI公司推出的Blackfin系列DSP获得了广泛的应用,其开发软件VisualDSP++提供了大量定点函数库可供用户使用,但其中的IIR滤波器函数iir_fr16要求滤波器系数必须在[-1,+1]范围内,这在应用上有很大的局限性。本文对IIR滤波器的结构和实现进行全面的分析后提出了优化方法,并设计一个8阶定点IIR低通滤波器进行验证,经仿真和实际测试,其性能指标完全达到设计要求。

Blackfin DSP designed by ADI company has been greatly applicated, whos software Visual DSP++ already supplies many fix- point functions, including IIR filter function- - iir_fr16. It requires all of coefficients must be during in [- 1,+1], that greatly lim- its its implication. This article gives a optimization after the comprehensive analyse in IIR filter structure. At last, Successfully design a eight- order fix- point lowpass filter, whos performance is perfectly satisfied with the need of the design.