摘 要

随着科学技术的飞速发展，数字信号处理技术广泛的应用于各种领域中，而数字滤波技术在数字信号处理中占有极其重要的地位。由于传统的模拟滤波器很难满足工业生产的需求，因此，对数字滤波器的研究具有重要的实际意义。相对于模拟滤波器，数字滤波器没有漂移，可以得到非常理想的频率响应特性，而且可以达到非常高的精度，这些优势决定了数字滤波器的应用将会越来越广泛。

本选题的主要内容是根据FIR数字滤波器的设计方法，包括窗函数法、频率响应法、等波纹逼近法，介绍这几种设计方法的原理及数字滤波器的发展概况和分类，分析了有限冲激响应（FIR）数字滤波器的数学模型及结构；然后，针对不同的设计思想，先后采用了窗函数法、频率采样法和等波纹最佳逼近法对不同类型的FIR数字滤波器进行编程设计，并进行了对比分析；最后，在Simulink环境下建立FIR数字滤波器的系统模型。利用FDA Tool工具，采用窗函数法设计低通滤波器验证建立的系统模型，同时使用多台示波器对滤波过程进行全程跟踪。运用MATLAB编写程序并用Simulink进行仿真验证，最后对这几种设计方法进行比较分析。

关键词：FIR数字滤波器，MATLAB，Simulink，FDA Tool

ABSTRACT

With the rapid development of science and technology, digital signal processing technology is widely used in various fields, and digital filtering technology plays an extremely important role in digital signal processing.Because the traditional analog filter is difficult to meet the demand of industrial production, the research of digital filter has important practical significance.Compared with the analog filter, the digital filter has no drift, it can obtain very ideal frequency response characteristics, and can achieve very high precision. These advantages make the digital filter more and more widely used.

According to the design methods of FIR digital filter, including window function method, frequency response method and equal-ripple approximation method, the principle of these design methods and the development and classification of digital filter are introduced.The mathematical model and structure of finite impulse response (FIR) digital filter are analyzed, and the window function method is used for different design ideas.Frequency sampling method and equal-ripple best approximation method are used to program and analyze different types of FIR digital filter. Finally, the system model of FIR digital filter is established in Simulink environment.Utilization The FDA Tool tool uses the window function method to design the low-pass filter to verify the established system model. At the same time, several oscilloscopes are used to track the whole process of the filter.The program is written by MATLAB and simulated by Simulink. Finally, the design methods are compared and analyzed.

Key words: Fir digital filter MATLAB Simulink Tool