基于MATLAB的IIR数字滤波器的设计技术

常用的低通巴特沃斯滤波器为例,介绍了基于MATLAB的数字滤波器的软件实现过程,通过软件仿真验证了结果的正确性,具有较强的通用性。     

高阶IIR滤波器的FPGA实现

结合IIR数字滤波器的基本结构,针对分布式算法中查找表规模过大的缺点,采用级联或并联结构,利用多块查找表使得硬件规模极大地减小,提出了并行和串行相结合的设计方案,并且实现了级联方式的10阶IIR低通滤波器。通过试验验证了该方法的有效性和实时性。     

基于Matlab GUI的数字滤波器设计

基于数字信号处理原理,在分析数字滤波器设计理论和Matlab编程技术及其GUI图形用户界面设计的基础上,开发了具有交互式特点的数字滤波器软件,界面操作简单方便,可以根据需要选择滤波器类型,输入相关参数,然后选择相应的功能按钮,就可以得到滤波器的特性参数,并进行滤波器的性能分析,打破了以往滤波器设计过程中大量繁琐的数值计算问题,为数字滤波器的设计和应用提供了一个有效的辅助工具。     

Design for 2-D error feedback networks with identical coefficient sets

In realization of recursive digital filters with fixed point arithmetic, an error caused by roundoff arises. It is known that the level of the roundoff noise of an IIR filter tends to be high when the poles are close to the unit circle. Error feedback (EF) is an effective method to reduce the roundoff noise. It is desirable to design an EF network using as few parameters as possible in order to keep computational costs low. In this paper, we propose a method for designing a 2D EF network with identical coefficient sets. That is, the EF coefficients are divided into several subsets such that all the elements within each set have the same absolute value. In order to optimize the coefficient sets, we propose an algorithm by using the genetic algorithm. In the numerical example, we demonstrate the effectiveness of the proposed method.     

A swarm intelligence approach to the synthesis of two-dimensional IIR filters

The concept of particle swarms, although initially introduced for simulating human social behaviors, has become very popular these days as an efficient means for intelligent search and optimization. The particle swarm optimization (PSO), as it is called now, does not require any gradient information of the function to be optimized, uses only primitive mathematical operators and is conceptually very simple. This paper investigates a novel approach to the designing of two-dimensional zero phase infinite impulse response (IIR) digital filters using the PSO algorithm. The design task is reformulated as a constrained minimization problem and is solved by a modified PSO algorithm. Numerical results are presented. The paper also demonstrates the superiority of the proposed design method by comparing it with two recently published filter design methods and two other state of the art optimization techniques.     

进化规划用于自适应IIR滤波器的优化设计

针对自适应ＩＲ滤波器（ＡＩＲＦ）潜在的不稳定性和性能指标函数容易陷入局部极小点而导致性能下降等问题，本文将进化规划用于直接、并联、级联和格型结构的ＡＩＩＲＦ的优化设计。基于进化规划的自适应滤波算法不依赖于梯度信息，能够有效地实现ＡＩＩＲＦ参数的全局寻优。大量的仿真实验结果表明不同结构的ＡＩＲＦ用进化规划进行参数寻优，不仅解决了自适应滤波器性能指标函数容易陷入局部极小点的问题，亦解决了ＡＩＲＦ的稳定性问题。     

高阶IIR数字滤波器的FPGA描述

介绍高阶IIR数字滤波器采用级联结构在FPGA上实现的方法。利用Matlab信号处理工具箱中的滤波器设计和分析工具（FDATool）很方便地设计出符合应用要求的未经量化的IIR滤波器，并进一步用VHDL语言加以描述，通过编译、功能仿真、综合和时序仿真之后就可以在FPGA上实现了。此设计扩展性好，在实际使用中，可适当修改外围参数改变滤波器的频率响应，根据不同的要求在不同规模的FPGA上加以实现。     

Realization of 2-D Variable IIR Digital Filter Structures with a Small Amount of Calculations for Coefficient Update

This paper proposes 2-D variable IIR digital filter structures with a small amount of calculations for coefficient update. The proposed realization method uses the 2-D parallel allpass structure derived from the separable denominator 2-D filter as the prototype structure for 2-D variable digital filters. In order to reduce the amount of calculations, all the redundant first-order complex allpass sections are combined by modularization of the variable structure. Furthermore, we can realize a very compact variable structure with a minimal number of first-order complex allpass sections by combining complex allpass sections with their complex conjugate allpass sections. Comparison of the calculation loads of the variable structures is presented to demonstrate that the amount of calculations for coefficient update of the proposed variable structure is far less than that of the original and the modular variable structure.     

使用实时自适应陷波器抑制多个窄带干扰

基于KWAN和MARTIN提出的抑制多个窄带干扰算法,改进了其中的梯度搜索算法,减少了硬件复杂性。KWAN和MARTIN的算法在窄带干扰数量增加时,硬件数量呈几何级数增长。而对于笔者改进的算法来说,硬件数量只需要代数增长就能够实现相同的效果。KWAN和MARTIN的算法在处理3至10个窄带干扰时,所需要的硬件数量分别比新算法多12.5%和124%。新算法的仿真结果显示了它在多种实际的信号处理应用中都是强壮和有效的。     

用DSP实现FSK

介绍用价格低廉的DSP实现FSK的方法。