【正文】 rder to filter out the noise in the signal or other inactive ingredient, it is critical to design a reliable and efficient digital filter. Interference signal contained in the input performance of the system will have a huge impact in the digital control system, so we need to deal with input signal in order to extract useful signal. FIR filter plays an important role in digital signal processing, we will use the MATLAB to simulate FIR digital filter designed to simplify the design of tedious calculations. In this paper, window function method, frequency sampling method and the equalripple approximation method will be used by calling the function of the MATLAB to design FIR digital filter design. After that, by using the FIR digital filters which have been designed to process the sound signal based on the MATLAB function, the filtering effect of different digital filters is analyzed by paring the signal?s spectrum viewers and the sound files which have been generated. The experimental results show that the FIR filters designed in this paper are effective. Comparing with mon FIR digital filter, we finally realize the efficient implementation of multiple sampling rate conversion system. 【 Key words】 FIR digital filter window method frequency sampling method equalripple approximation multisampling rate conversion 重慶郵電大學(xué)本科畢業(yè)設(shè)計(jì)（論文） IV 目 錄 前 言 ..........................................................................................................................1 第一章 數(shù)字濾波器的理論研究 ..................................................................................2 第一節(jié) 數(shù)字濾波器的基本原理和結(jié)構(gòu) ................................................................2 第二節(jié) IIR 與 FIR濾波器的比較 ..........................................................................4 第三節(jié) 本章小結(jié) ....................................................................................................5 第二章 FIR濾波器的設(shè)計(jì) ............................................................................................6 第一節(jié) 窗函數(shù)法設(shè)計(jì) FIR濾波器 ........................................................................6 一、窗函數(shù)法設(shè)計(jì) FIR數(shù)字濾波器 ...............................................................6 二、常用的窗函數(shù) ...........................................................................................8 第二節(jié) 頻率采樣法設(shè)計(jì) FIR濾波器 ..................................................................11 一、頻率采樣法設(shè)計(jì) FIR數(shù)字濾波器的基本原理 .....................................11 二、頻率采樣法設(shè)計(jì)線性相位濾波器的條件 .............................................11 三、逼近誤差及其采樣措施 .........................................................................12 四、頻率采樣法設(shè)計(jì) FIR濾波器的步驟 .....................................................13 第三節(jié) 等波紋逼近法設(shè)計(jì) FIR數(shù)字濾波器 ......................................................13 一、等波紋最佳逼近的原理 .........................................................................14 二、利用最佳一致逼近準(zhǔn)則設(shè)計(jì)線性相位 FIR數(shù)字濾波器 .....................15 第四節(jié) 本章小結(jié) ..................................................................................................16 第三章 Matlab 實(shí)現(xiàn) FIR數(shù)字濾波器 .......................................................................17 第一節(jié) Matlab 實(shí)現(xiàn)窗函數(shù)法設(shè)計(jì) ......................................................................17 一、 Matlab 實(shí)現(xiàn)窗函數(shù)法的設(shè)計(jì) .................................................................17 二、利用窗函數(shù)法設(shè)計(jì)濾波器 .....................................................................18 第二節(jié) Matlab 實(shí)現(xiàn)頻率采樣法設(shè)計(jì) ..................................................................22 第三節(jié) Matlab 實(shí)現(xiàn)等波紋逼近法設(shè)計(jì) ..............................................................23 重慶郵電大學(xué)本科畢業(yè)設(shè)計(jì)（論文） V 一、利用最佳逼近法設(shè)計(jì) FIR數(shù)字帶通濾波器 .........................................24 二、 FIR濾波器約束最小二乘法設(shè)計(jì)分析 ..................................................24 三、 FIR濾波器任意頻響設(shè)計(jì)法設(shè)計(jì)分析 ..................................................26 第四節(jié) 語(yǔ)音濾波分析 ..........................................................................................27 一、利用等波紋逼近法設(shè)計(jì)的 LPF 對(duì)加噪聲音濾波 ................................27 二、 GUI 設(shè)計(jì)及濾波結(jié)果分析 .....................................................................28 三、頻率采樣法設(shè)計(jì)的 HPF 對(duì)語(yǔ)音濾波 ....................................................31 第五節(jié) 本章小結(jié) ..................................................................................................32 第四章 多采樣率數(shù)字信號(hào)處理的研究 ....................................................................33 第一節(jié) 多采樣率數(shù)字信號(hào)處理工程需求 ..........................................................33 一、按整數(shù)因子抽取 .....................................................................................33 二、按整數(shù)因子內(nèi)插 .....................................................................................35 三、按有理因子 I/D 采樣率內(nèi)插 ..................................................................36 第二節(jié) 多采樣率轉(zhuǎn)換濾波器的設(shè)計(jì) ..................................................................36 一、多相濾波器的實(shí)現(xiàn) .................................................................................36 二、采樣率轉(zhuǎn)換系統(tǒng)的多級(jí)實(shí)現(xiàn) .................................................................37 第三節(jié) 用 Matlab 設(shè)計(jì)采樣率轉(zhuǎn)換濾波器 .........................................................38 第四節(jié) 本章小結(jié) ..................................................................................................41 總 結(jié) ........................................................................................................................43 致 謝 ........................................................................................................................44 參考文獻(xiàn) ........................................................................................................................45 附 錄 ........................................................................................................................49 一、英文原文 : .......................................................................................................49 二、英文翻譯： ............................