目錄 

 

摘要 5

Abstract 6

1 緒論 7

1.1 選題的依據(jù)和意義 7

1.2 數(shù)字濾波器的研究背景 7

1.3 數(shù)字濾波器的應(yīng)用和現(xiàn)狀 8

1.4 MATLAB簡介 8

2 FIR濾波器的線性相位 9

2.1 FIR濾波器的概述 9

2.2 FIR濾波器線性相位的定義 10

2.3 FIR濾波器線性相位約束條件 10

3 FIR濾波器的設(shè)計方法 11

3.1 窗函數(shù)設(shè)計法 11

3.1.1 窗函數(shù)法的設(shè)計思路 11

3.1.2 吉布斯效應(yīng) 13

3.1.3 幾種典型窗函數(shù)的介紹 13

3.1.4 窗函數(shù)法具體設(shè)計實例 15

3.2 頻率采樣法 19

3.2.1 頻率采樣法的設(shè)計思路 19

3.2.2 頻率采樣法的設(shè)計步驟與實例 20

3.3 等波紋逼近法及設(shè)計實例 23

3.4 不同設(shè)計方法間的比較 26

4 基于MATLAB的FIR濾波器設(shè)計 27

4.1 窗函數(shù)法的MATLAB實現(xiàn) 27

4.2 頻率采樣法的MATLAB實現(xiàn) 33

4.3 等波紋逼近法的MATLAB實現(xiàn) 34

5 總結(jié) 38

6 致謝 39

7 參考文獻(xiàn) 40

附錄 41

   程序1 41

   程序2 43

   程序3 44

基于MATLAB的FIR濾波器設(shè)計

摘要

    FIR濾波器是組成數(shù)字信號處理中一個比較關(guān)鍵性的部分，因為它有著嚴(yán)格線性相位，所以它在信號處理過程當(dāng)中被普遍地采用。本文主要涉及FIR濾波器的基本概念以及具備線性相位的條件，主要分析用窗函數(shù)法，頻率采樣法以及等波紋逼近法來設(shè)計FIR濾波器的思路、流程，進(jìn)行程序編寫設(shè)計。對比仿真設(shè)計結(jié)果可以得出：選擇用這三種設(shè)計法設(shè)計出來的FIR濾波器，從相頻上來看，它們在通帶內(nèi)，都是具有線性相位的；而從幅頻特性上來看，等波紋逼近法相對于另外兩種設(shè)計法來說，設(shè)計出來的FIR濾波器具有邊界頻率精確，階數(shù)低，平坦的通帶和阻帶以及過渡帶窄。

關(guān)鍵詞：FIR低通濾波器，MATLAB，窗函數(shù)法，頻率采樣法，等波紋逼近法

The design of FIR filter based on MATLAB

Abstract

  FIR filter is composed of a more critical part of the digital signal processing, because it has a strict linear phase, so it is widely used in the signal processing. This article mainly involves the basic concept of FIR filter, and have the conditions of the linear phase, the main analysis the thought of method using window function, frequency sampling method and equiripple approximation method to design, process of FIR filter to design programming.Comparative simulation results can be concluded that: choose the three design of FIR filter design method, from the phase frequency point of view, they within the passband, are all with linear phase; And on the amplitude-frequency characteristic of it, such as corrugated equiripple approximation method for the other two kind of design method, the design of FIR filter with boundary frequency precision, low order, flat passband and stopband and narrow transition band.

Key words：FIR low-pass filter，MATLAB，Windowing method，F(xiàn)requency sampling method，Equiripple approximation method