一种用Remez函数设计FIR数字滤波器的设计方法.doc

摘 要 滤波是信号处理中最基本又极为重要的技术，利用滤波器技术可以从复杂的信号中提取出所需要的信号，抑制不需要的信号。绝大多数传感器输出的信号，在使用过程中，都必须进行滤波。所以滤波器是具有一定传输选择特性的、对信号进行加工处理的装置、它允许输入信号中的一些成分通过，抑制或衰减另一些成分。其功能是将输入信号变换为人们所需要的输入信号。 在这个极具挑战的时代中，把计算机充分运用到教学及工程计算中，显然具有重要的意义，而随着计算机技术的发展,计算机软件在工程设计领域的应用越来越广。 本文介绍了一种用Remez函数设计FIR数字滤波器的设计方法，并利用MATLAB强大的功能进行仿真。仿真结果表明，设计结果的各项性能指标均达到较高要求，并且该方法是一种最优化的设计方法。在同样的技术指标下，用这种方法得到的滤波器要比窗函数法、频率采样法得到滤波器的长度均要小，并且克服了窗函数设计法和频率采样法的缺点，使最大误差最小化，并在整个逼近频段上均匀分布。 关键词：FIR数字滤波器；窗函数设计法；频率采样法；等波纹最优化设计法；MATLAB；Remez函数 Abstract Filtering is the most basic and extremely important technology in signal processing . Use Filter technology,and you can extract the signal from the complex signals and suppress unwanted signals. The vast majority of the sensor output signals, in the course, must be filtered.Thus,Filter is a signal processing device with a certain transmission select features,which allows some components of the input signals through,inhibition or attenuation of some other components. Its function is to transform the input signals to the required input signals. In this very challenging times, the computer fully applied to the teaching and engineering calculations,is clearly of great significance.With the development of computer technology, computer software is more widely applied in the field of engineering design. This article describes a Remez function of FIR digital filter design methods, and simulation using MATLABs powerful features. The simulation results show that the design results of the performance indicators to meet the higher requirements, and the method is an optimized design method. Under the same technical specifications of the filter obtained by this method than the window function method, frequency sampling method to get the length of the filter are smaller, and to overcome the shortcomings of the window function design method and frequency sampling method, the maximum error minimize and evenly distributed throughout the approximation band. Key words：FIR digital filter；window function design