基于Hanning Window设计FIR数字高通滤波器

基于实序列的傅里叶变换具有的特征,提出了一种研究线性相位FIR数字滤波器幅度函数的简洁方法。首先揭示了偶对称和奇对称的线性相位FIR数字滤波器幅度函数的特点;然后研究了矩形窗函数对线性相位理想数字低通滤波器幅频特性的影响,即时域加矩形窗,频域形成过渡带;最后介绍了利用窗函数法设计FIR数字滤波器时,对窗函数的要求,选择窗函数的依据及利用窗函数法设计FIR数字滤波器的步骤,并给出了基于Hanning Window来设计FIR数字高通滤波器的实例。     

基于神经网络的FRM滤波器优化设计研究

以频率响应屏蔽(FRM)技术为基础,提出了一种基于神经网络的窄过渡带FIR数字滤波器的优化设计新方法.该算法主要通过使频率响应平方误差函数最小化来获得FRM滤波器系数.文中详细介绍了基于神经网络的基本FRM滤波器和多层FRM滤波器的设计算法及设计步骤,证明了该算法的稳定性定理,给出了仿真实例,并与已有的设计方法进行了比较,设计结果表明用该方法设计的窄过渡带FIR数字滤波器性能更为优越.     

基于遗传算法的FIR滤波器设计

提出一种FIR数字滤波器的优化设计方法,即将遗传算法应用于频率采样法的FIR数字滤波器设计中。结合给定的FIR数字带通滤波器的技术指标,用遗传算法得到频率采样法中过渡带的最佳采样值,并分别用遗传算法与查表法对过渡带中采样点的频率采样法进行仿真实现。实验结果表明,采用遗传算法设计FIR数字滤波器可获得最大的阻带最小衰减,从而解决了传统查表法不能保证最优的问题。     

一种有效的IIR数字滤波器优化设计方法

针对IIR数字滤波器优化设计实质上是一个多参数多目标优化问题,本文提出一种基于量子遗传算法的IIR数字滤波器满意优化设计方法,通过设计满意度函数而构造出满意优化计算模型,将滤波器性能指标的满意设计与参数优化统一考虑,并用本文提出的收敛速度快和全局寻优能力强的新量子遗传算法(NQGA)搜索满意解。通过低通和带通IIR数字滤波器的设计结果表明,该方法是有效、实用的。     

基于改进遗传量子算法的FIR数字滤波器设计

采用改进遗传量子算法(IGQA)进行FIR数字滤波器的优化设计,将滤波器的过渡带样本值作为变量进行优化,解决了传统方法(查表法)不能保证数据最优的问题。针对遗传量子算法(GQA)在优化连续多峰函数时易出现早熟的问题,提出一种改进遗传量子算法(IGQA),典型函数测试表明,IGQA的性能优于GQA和其它几种遗传算法,收敛速度快,全局寻优能力强,能有效地克服早熟现象。采用IGQA优化设计的FIR数字低通和带通滤波器的性能较查表法得到了很大改善。     

基于椭圆球面波函数的数字带通滤波器设计

为设计频谱性能优良的有限冲激响应( FIR)数字带通滤波器,从窗函数的性质及选择指标出发,分析了椭圆球面波函数( PSWF)作为窗函数的优势;在此基础上根据数字滤波器设计的原理和要求,选择0阶基带椭圆球面波函数作为窗函数设计数字带通滤波器,并利用微分方程状态转移矩阵逼近的PSWF求解算法,给出了基于PSWF的FIR数字带通滤波器设计方法。理论分析和仿真结果表明：PSWF数字带通滤波器具有较低的设计复杂度,与Kaiser滤波器和Blackman滤波器相比,其旁瓣衰减有超过7 dB的优势,且具有与两种滤波器相当的通带波纹波动和过渡带宽。     

一种基于频率响应屏蔽技术的FIR滤波器设计新方法

提出了一种设计高效窄过渡带宽FIR滤波器的新方法。该方法以传统的频率响应屏蔽(FRM)方法为基础,通过选择特定的原型滤波器来降低合成的数字FIR滤波器的复杂度。本文研究了该方法的原理、实现结构和设计方法,并通过设计实例证明了此方法的有效性。     

基于免疫算法的FIR数字滤波器优化设计

针对频率采样技术设计FIR滤波器的特点,推导出阻带衰减关于滤波器阶数和过渡带采样值的优化函数,并具体设计了免疫算法对其优化求解.仿真验证表明,较之以往方法,其效果较好,对基于频率采样技术的FIR滤波器优化设计具有重要意义.     

浅谈学习窗函数法设计FIR数字滤波器体会

FIR数字滤波器在工程上运用广泛,窗函数法设计FIR数字滤波器是典型的设计方法.目前,相关课程的教科书对窗函数法设计FIR数字滤波器这部分内容讲解不够细致,学生掌握感到有难度.本文针对窗函数法设计FIR数字滤波器的相关问题,即数字滤波器与模拟样本滤波器的关系、截断点如何取值和数字滤波器的线性相移特性,结合实例进行分析,并借助Matlab仿真软件对设计进行了分析和验证.     

用频率采样法设计FIR滤波器

窗函数法和频率采样法是两种较为典型的FIR数字滤波器设计方法。目前,相关的《数字信号处理》教科书对窗函数法设计FIR滤波器进行了较为详细的论述,但对用频率采样法设计FIR滤波器这部分内容讲解得不够细致,让初学的学生感到难以理解。针对用频率采样法设计FIR滤波器的相关问题进行了较为深入的探讨,并结合实例借助Matlab软件进行了仿真和验证。仿真结果表明,选择合适的过渡采样点和滤波器长度,可以有效地控制阻带衰减、过渡带宽及计算复杂度。     

基于FIR与相位补偿IIR滤波器的雷达回波信号处理

FIR与IIR频率选择滤波器的设计,被广泛应用于数字信号处理领域之中。文章以雷达回波信号的数字处理为例,首先分别设计FIR,IIR滤波器完成了对信号特定频率分量的滤除。进而,针对IIR滤波器的非线性相位,基于最优化设计全通系统实现了相位补偿,并对FIR,IIR滤波器进行了综合比较。     

Analytical design method for optimal equiripple comb FIR filters

A novel analytical design method for highly selective digital optimal equiripple comb finite-impulse response (FIR) filters is presented. The equiripple comb FIR filters are optimal in the Chebyshev sense. The number of notch bands, the width of the notch bands and the attenuation in the passbands can be independently specified. The degree formula and the differential equation for the generating polynomial of the filter is presented. Based on the differential equation, a fast simple algebraic recursive procedure for the evaluation of the impulse response of the filter is described. Its arithmetic robustness outperforms, by far, the known analytical design method. Highly selective equiripple comb FIR filters with thousands of coefficients can be designed. One example demonstrates the efficiency of the filter design.     

A novel method for designing FIR digital filters with nonuniform frequency samples

A new method of designing FIR digital filters using nonuniform frequency samples is presented. There is no restriction on the phase to be linear. The method is based on a Newton-type polynomial interpolating on the unit circle of the complex plane. Attractive features of the proposed method are the applicability to unequally spaced samples, the recursive and semipermanent computation of filter parameters, the capability of obtaining short transition bands or sharp cut-off frequency responses, and the design of efficient algorithms for real-time applications. In the serial case, when the next sample appears, the design parameters are evaluated only by updating the old ones with correction terms that could be used as indicators for convergence, approximation, or filter reduction. The method can be extended to m-D filter design, DFT calculation, design of parallel algorithms, etc.<>     

A digital signal processing approach to interpolation

In many digital signal precessing systems, e.g., vacoders, modulation systems, and digital waveform coding systems, it is necessary to alter the sampling rate of a digital signal Thus it is of considerable interest to examine the problem of interpolation of bandlimited signals from the viewpoint of digital signal processing. A frequency dmnain interpretation of the interpolation process, through which it is clear that interpolation is fundamentally a linear filtering process, is presented, An examination of the relative merits of finite duration impulse response (FIR) and infinite duration impulse response (IIR) digital filters as interpolation filters indicates that FIR filters are generally to be preferred for interpolation. It is shown that linear interpolation and classical polynomial interpolation correspond to the use of the FIR interpolation filter. The use of classical interpolation methods in signal processing applications is illustrated by a discussion of FIR interpolation filters derived from the Lagrange interpolation formula. The limitations of these filters lead us to a consideration of optimum FIR filters for interpolation that can be designed using linear programming techniques. Examples are presented to illustrate the significant improvements that are obtained using the optimum filters.     

Design of Linear Phase FIR Filters in Subexpression Space Using Mixed Integer Linear Programming

In this paper, a novel optimization technique is proposed to optimize filter coefficients of linear phase finite-impulse response (FIR) filter to share common subexpressions within and among coefficients. Existing approaches of common subexpression elimination optimize digital filters in two stages: first, an FIR filter is designed in a discrete space such as finite wordlength space or signed power-of-two (SPT) space to meet a given specification; in the second stage, an optimization algorithm is applied on the discrete coefficients to find and eliminate the common subexpressions. Such a two-stage optimization technique suffers from the problem that the search space in the second stage is limited by the finite wordlength or SPT coefficients obtained in the first stage optimization. The new proposed algorithm overcomes this problem by optimizing the filter coefficients directly in subexpression space for a given specification. Numerical examples of benchmark filters show that the required number of adders obtained using the proposed algorithm is much less than those obtained using two-stage optimization approaches.     

A Tutorial on Multiplierless Design of FIR Filters: Algorithms and Architectures

Finite impulse response (FIR) filtering is a ubiquitous operation in digital signal processing systems and is generally implemented in full custom circuits due to high-speed and low-power design requirements. The complexity of an FIR filter is dominated by the multiplication of a large number of filter coefficients by the filter input or its time-shifted versions. Over the years, many high-level synthesis algorithms and filter architectures have been introduced in order to design FIR filters efficiently. This article reviews how constant multiplications can be designed using shifts and adders/subtractors that are maximally shared through a high-level synthesis algorithm based on some optimization criteria. It also presents different forms of FIR filters, namely, direct, transposed, and hybrid and shows how constant multiplications in each filter form can be realized under a shift-adds architecture. More importantly, it explores the impact of the multiplierless realization of each filter form on area, delay, and power dissipation of both custom (ASIC) and reconfigurable (FPGA) circuits by carrying out experiments with different bitwidths of filter input, design libraries, reconfigurable target devices, and optimization criteria in high-level synthesis algorithms.     

QPSO算法在FIR数字滤波器设计中的应用

FIR数字滤波器的设计实际上是一个多维变量寻优问题,滤波器的设计可转化为滤波器参数优化的问题。文章介绍了粒子群优化算法、量子粒子群优化算法,然后利用算法对参数空间进行搜索以获得参数的最优化,根据预期频率特性的设计要求,通过仿真实验表明设计方法的有效性。     

Frequency domain synthesis of IIR digital filters by means of associated FIR filters

This correspondence describes a synthesis technique for IIR digital filters which allows the use of approximation methods already developed for designing FIR filters. The technique is based on the definition, by means of a suitable transformation, of a FIR filter associated to the desired IIR filter. An example of application is given and the related results are briefly discussed.