基于matlab的數(shù)字信號(hào)處理課程設(shè)計(jì)

1、<p>　　基于Matlab的數(shù)字信號(hào)處理課程設(shè)計(jì)</p><p>　　基于Matlab的數(shù)字信號(hào)處理課程設(shè)計(jì)</p><p><b>　　一、課程設(shè)計(jì)目的：</b></p><p>　　1．熟悉Matlab運(yùn)行環(huán)境，熟練使用Matlab語(yǔ)言進(jìn)行編程，進(jìn)行數(shù)字信號(hào)處理。</p><p>　　2．全面復(fù)習(xí)數(shù)字信號(hào)

2、課程所學(xué)理論知識(shí)，鞏固所學(xué)知識(shí)重點(diǎn)和難點(diǎn)，將理論與實(shí)踐很好地結(jié)合起來(lái)。</p><p>　　3．提高綜合運(yùn)用所學(xué)知識(shí)獨(dú)立分析和解決問(wèn)題的能力；</p><p>　　二、 MATLAB簡(jiǎn)介</p><p>　　MATLAB是功能強(qiáng)大的科學(xué)及計(jì)算軟件，它不但具有以矩陣計(jì)算為基礎(chǔ)的強(qiáng)大數(shù)學(xué)計(jì)算和分析功能，而且還具有豐富的可視化圖形表現(xiàn)功能和方便的程序設(shè)計(jì)能力。MATLAB

3、的應(yīng)用領(lǐng)域極為廣泛，除了數(shù)學(xué)計(jì)算和分析外，還被廣泛地應(yīng)用于自動(dòng)控制、系統(tǒng)仿真、數(shù)字信號(hào)處理、圖形圖像分析、數(shù)理統(tǒng)計(jì)、人工智能、虛擬現(xiàn)實(shí)技術(shù)、通信工程、金融系統(tǒng)等領(lǐng)域，因此，MATLAB是面向21世紀(jì)的計(jì)算機(jī)程序設(shè)計(jì)及科學(xué)計(jì)算語(yǔ)言。</p><p>　　三、MATLAB的主要組成部分</p><p>　　MATLAB系統(tǒng)包括5個(gè)主要部分：</p><p><b&

4、gt;　　（1）開(kāi)發(fā)環(huán)境</b></p><p>　　MATLAB開(kāi)發(fā)環(huán)境由一組工具和組件組成，這些工具是圖形化的用戶(hù)界面，包括MATLAB桌面和命令窗口、命令歷史窗口、幫助信息瀏覽器、文件和搜索路徑瀏覽器。</p><p>　　（2）MATLAB數(shù)學(xué)函數(shù)庫(kù)</p><p>　　MATLAB集成了豐富的數(shù)學(xué)函數(shù)庫(kù)，其強(qiáng)大的計(jì)算能力覆蓋了從基本函數(shù)（如求和

5、、正弦、余弦和復(fù)數(shù)運(yùn)算等）到高級(jí)函數(shù)（如矩陣求逆、矩陣特征值、貝塞爾函數(shù)和快速傅立葉變換等）的范圍。</p><p>　?。?）MATLAB語(yǔ)言</p><p>　　MATLAB語(yǔ)言是一種以矩陣運(yùn)算為基礎(chǔ)的高級(jí)語(yǔ)言，包括控制流的描述、函數(shù)、數(shù)據(jù)結(jié)構(gòu)、輸入輸出及面向?qū)ο蟮木幊汰h(huán)境，既可以編制快速使用小程序，也可以編制大型復(fù)雜的應(yīng)用程序。</p><p><b&g

6、t;　?。?）圖形功能</b></p><p>　　MATLAB提供了功能強(qiáng)大的圖形系統(tǒng)，既可以用高級(jí)命令完成二維和三維數(shù)據(jù)的可視化、圖像處理、動(dòng)畫(huà)和圖形表達(dá)等功能，也可以通過(guò)使用圖形句柄完成復(fù)雜的圖形功能，實(shí)現(xiàn)對(duì)所有圖形對(duì)象的操作。</p><p>　?。?）應(yīng)用程序接口（API）</p><p>　　MATLAB還提供了應(yīng)用程序接口庫(kù)函數(shù)，允許用戶(hù)使

7、用C或FORTRAN語(yǔ)言編寫(xiě)程序與MATLAB連接，功能包括與MATLAB的動(dòng)態(tài)連接、調(diào)用MATLAB作為運(yùn)算引擎、讀寫(xiě)MAT文件等。</p><p>　　MATLAB的廣泛應(yīng)用促進(jìn)了其本身功能的迅速發(fā)展，以特定領(lǐng)域的應(yīng)用為主要目的的應(yīng)用程序——工具箱的數(shù)量和內(nèi)容在不斷增多。</p><p>　　四、利用Matlab熟悉畫(huà)圖（設(shè)計(jì)1）</p><p>　　1、設(shè)計(jì)內(nèi)

8、容：能夠利用Matlab熟悉地畫(huà)圖，內(nèi)容包括：X、Y坐標(biāo)軸上的label，每幅圖上的title，繪畫(huà)多條曲線(xiàn)時(shí)的legend，對(duì)圖形進(jìn)行適當(dāng)?shù)臉?biāo)注等。</p><p>　?。?）在一副圖上畫(huà)出多幅小圖；</p><p>　　（2）畫(huà)出一組二維圖形；</p><p>　?。?）畫(huà)出一組三維圖形； </p><p>　?。?）畫(huà)出復(fù)數(shù)的實(shí)

9、部與虛部。</p><p><b>　　實(shí)驗(yàn)結(jié)果：</b></p><p>　　、在一副圖上畫(huà)出多幅小圖；</p><p>　　、畫(huà)出一組二維圖形；</p><p>　　、畫(huà)出一組三維圖形；</p><p>　　、畫(huà)出復(fù)數(shù)的實(shí)部與虛部；</p><p>　　（5）、完成對(duì)一

10、個(gè)源程序進(jìn)行詳細(xì)注釋。（見(jiàn)程序）</p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p>　　% 能夠利用Matlab熟悉地畫(huà)圖，內(nèi)容包括：X、Y坐標(biāo)軸上的label，</p><p>　　% 每幅圖上的titl

11、e，繪畫(huà)多條曲線(xiàn)時(shí)的legend，對(duì)圖形進(jìn)行適當(dāng)?shù)臉?biāo)注等。</p><p>　　% （1）在一副圖上畫(huà)出多幅小圖；（2）畫(huà)出一組二維圖形；</p><p>　　% （3）畫(huà)出一組三維圖形； （4）畫(huà)出復(fù)數(shù)的實(shí)部與虛部。</p><p>　　% （5）完成對(duì)一個(gè)源程序進(jìn)行詳細(xì)注釋。</p><p>　　%%

12、%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p><b>　　clear;</b></p><p><b>　　clc;</b></p><p>　　x=linspace(-pi,pi,200);

13、 % 定義x軸坐標(biāo)</p><p>　　y1=sin(x); % 函數(shù)1</p><p>　　y2=cos(x); % 函數(shù)2</p><p>　　y3=exp(x);

14、 % 函數(shù)3</p><p>　　y4=sin(x).*cos(x); % 函數(shù)4</p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%% 在一幅圖上繪制多幅小圖 %%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p><b>　　figure(1)</

15、b></p><p>　　subplot(221), % 圖一</p><p>　　plot(x,y1); % 繪制y1</p><p>　　grid on; % 添加網(wǎng)格&

16、lt;/p><p>　　% axis([min(x) max(x) min(y1) max(y1)]); % 指定顯示范圍</p><p>　　subplot(222), % 圖二</p><p>　　hist(y2); % 繪制y2</

17、p><p>　　grid on; % 添加網(wǎng)格</p><p>　　% axis([min(x) max(x) min(y2) max(y2)]); % 指定顯示范圍</p><p>　　subplot(223), % 圖三</p>

18、;<p>　　stem(x,y3); % 繪制y3</p><p>　　grid on; % 添加網(wǎng)格</p><p>　　% axis([min(x) max(x) min(y3) max(y3)]); % 指定顯示范圍</p>

19、<p>　　subplot(224), % 圖四</p><p>　　plot(x,y4,'rp'); % 繪制y4</p><p>　　grid on; % 添加網(wǎng)格</p>

20、;<p>　　% axis([min(x) max(x) min(y4) max(y4)]); % 指定顯示范圍</p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 畫(huà)出一組二維圖形 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p>　　figure(2)

21、 </p><p>　　a=linspace(0,2*pi,200);</p><p>　　k=[1,2,3];</p><p>　　y=sin(a')*k;</p><p>　　plot(a,y(:,1),a,y(:,2),a,y(:,3));</p><p>　　legend(['y= '

22、,num2str(k(1)),'*sin(x)'],['y= ',num2str(k(2)),'*sin(x)']...</p><p>　　,['y= ',num2str(k(3)),'*sin(x)']);</p><p>　　xlabel('x');</p><p>

23、;　　ylabel('y');</p><p>　　title('多條曲線(xiàn)繪制');</p><p><b>　　grid on;</b></p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 畫(huà)出一組三維圖形 %%%%%%%%%%%%%%%%%%%%%%%%%%%%</p>

24、;<p>　　figure(3) </p><p><b>　　kk=30;</b></p><p>　　x=linspace(-5,5,kk);</p><p>　　y=linspace(-5,5,kk);</p><p>　　for i=

25、1:kk</p><p>　　for j=1:kk</p><p>　　z(i,j)=sin(x(i))+cos(y(j));</p><p><b>　　end</b></p><p><b>　　end</b></p><p>　　surf(x,y,z);</p&g

26、t;<p>　　xlabel('x');</p><p>　　ylabel('y');</p><p>　　zlabel('z');</p><p>　　title('z=sin^2(x)/(3*y-2)');</p><p>　　%%%%%%%%%%%%%%%%%

27、%%%%%%%%%%%%%%%%% 復(fù)數(shù)繪制 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p>　　figure(4) </p><p><b>　　clear</b></p><p>　　kk=1:1:10;</p><p>　　for i=1:10</p><p&g

28、t;　　y(i)=sin(kk(i))+cos(kk(i))/kk(i)*j;</p><p><b>　　end</b></p><p>　　compass(y);</p><p>　　五、褶積的相關(guān)計(jì)算與編程（設(shè)計(jì)2）</p><p>　　設(shè)計(jì)內(nèi)容：計(jì)算普通褶積與循環(huán)褶積，分別使用時(shí)間域與頻率域兩種方法進(jìn)行正、反演計(jì)

29、算，指出循環(huán)褶積計(jì)算時(shí)所存在的邊界效應(yīng)現(xiàn)象；編寫(xiě)一個(gè)做相關(guān)分析的源程序。</p><p><b>　　實(shí)驗(yàn)成果：</b></p><p>　?。?）、構(gòu)造如下兩個(gè)向量：a=[1,2,3,4]; b=[9,8,7,6]; </p><p><b>　　計(jì)算得到：</b></p><p>　　從計(jì)

30、算結(jié)果可以看出，當(dāng)循環(huán)次數(shù)小于N1+N2-1時(shí)，線(xiàn)性褶積和循環(huán)褶積不等，</p><p>　　當(dāng)循環(huán)次數(shù)大于等于N1+N2-1時(shí)，線(xiàn)性褶積和循環(huán)褶積相等。</p><p>　　（2）、構(gòu)造兩個(gè)向量：a=[1 2 3]; b=[1 2 3 5];</p><p>　　計(jì)算相關(guān)得到：頻率域： [14 13 16 23]</p><p>　　時(shí)

31、間域（6次）： [14 8 3 5 13 23]</p><p><b>　　程序：</b></p><p><b>　　褶 積 </b></p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p&

32、gt;<p>　　% 計(jì)算普通褶積與循環(huán)褶積，分別使用時(shí)間域與頻率域兩種方法</p><p>　　% 進(jìn)行正、反演計(jì)算，指出循環(huán)褶積計(jì)算時(shí)所存在的邊界效應(yīng)現(xiàn)象；</p><p>　　% 編寫(xiě)一個(gè)做相關(guān)分析的源程序。 </p><p>　　%%%%%%

33、%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p>　　% 驗(yàn)證循環(huán)褶積和線(xiàn)性褶積在什么條件下相等</p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

34、%%%%%%%%</p><p><b>　　clc;</b></p><p><b>　　clear;</b></p><p>　　a=[1,2,3,4]; % a矩陣</p><p>　　b=[9,8,7,6]; % b矩陣</p>

35、<p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p>　　kk1=length(a);</p><p>　　kk2=length(b);</p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

36、%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p>　　% 循環(huán)褶積 時(shí)間域</p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p>　　xx=

37、8; % 循環(huán)次數(shù) 手動(dòng)更改</p><p>　　aa=zeros(xx,1);</p><p>　　aa(1:kk1,1)=a'; % 擴(kuò)展a</p><p>　　bb=zeros(xx,1);</p><p>　　bb(1:kk2,1)=b'; %

38、擴(kuò)展b</p><p>　　bb1=zeros(xx,xx); % 循環(huán)矩陣</p><p>　　for i=1:xx</p><p>　　bb1(i:xx,i)=bb(1:xx-i+1);</p><p>　　bb1(1:i-1,i)=bb(xx-i+2:xx);</p><p><b>　　

39、end</b></p><p>　　ok1=bb1*aa; % 循環(huán)褶積結(jié)果</p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p>　　% 線(xiàn)性褶

40、積 時(shí)間域</p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p>　　bb2=zeros(kk1+kk2-1,kk1);</p><p>　　for i=1:kk1</p><p>　　bb2(i:i+kk2-

41、1,i)=b(1:kk2)';</p><p><b>　　end</b></p><p><b>　　an=a';</b></p><p>　　ok2=bb2*an; % 線(xiàn)性褶積結(jié)果</p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%%

42、%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p>　　% 循環(huán)褶積 頻率域</p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p>&l

43、t;p>　　af=fft(aa);</p><p>　　bf=fft(bb);</p><p>　　ok3=ifft(af.*bf);</p><p><b>　　相 關(guān) </b></p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

44、%%%%%%%%%%%%%%%%%%</p><p>　　% 計(jì)算普通褶積與循環(huán)褶積，分別使用時(shí)間域與頻率域兩種方法進(jìn)行</p><p>　　% 正、反演計(jì)算，指出循環(huán)褶積計(jì)算時(shí)所存在的邊界效應(yīng)現(xiàn)象；</p><p>　　% 編寫(xiě)一個(gè)做相關(guān)分析的源程序。 <

45、;/p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p>　　% 求兩個(gè)一維數(shù)組的相關(guān)系數(shù)</p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

46、%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p><b>　　clear;</b></p><p><b>　　clc;</b></p><p>　　a=[1 2 3]; % 數(shù)組a 較短時(shí)可以手動(dòng)輸入</p><p>　　b=[

47、1 2 3 5]; % 數(shù)組b 較短時(shí)可以手動(dòng)輸入</p><p>　　% a=csvread('**.csv',0,0); % 數(shù)組a 較長(zhǎng)時(shí)可以讀取csv文件</p><p>　　% b=csvread('**.csv',0,0); % 數(shù)組a 較長(zhǎng)時(shí)可以讀取csv文件</p>&

48、lt;p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p>　　% 頻率域求相關(guān)</p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

49、%%%%%%%%%%%%%%%%%%%%%%%</p><p>　　a2=zeros(1,max(length(a),length(b)));</p><p>　　b2=zeros(1,max(length(a),length(b)));</p><p>　　a2(1,1:length(a))=a;</p><p>　　b2(1,1:leng

50、th(b))=b;</p><p>　　ffta=fft(a2);</p><p>　　fftb=fft(b2);</p><p>　　fftb=conj(fftb);</p><p>　　result=(ifft(ffta.*fftb))' % 頻率域求相關(guān)結(jié)果</p><p>　　%%%%%%%

51、%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p>　　% 時(shí)間域求相關(guān)</p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

52、%%%%%%</p><p>　　long=length(a)+length(b)-1;</p><p>　　aa=zeros(long,1);</p><p>　　bb=zeros(long,1);</p><p>　　aa(1:length(a),1)=a';</p><p>　　bb(1:length(b

53、),1)=b';</p><p>　　temp=zeros(long);</p><p>　　for i=1:long</p><p>　　temp(1:long-i+1,i)=aa(i:long);</p><p>　　temp(long-i+2:long,i)=aa(1:i-1);</p><p><

54、b>　　end</b></p><p>　　result2=temp*(bb) % 時(shí)間域求循環(huán)相關(guān)</p><p>　　六、設(shè)計(jì)一維濾波處理程序（設(shè)計(jì)3）</p><p>　　實(shí)驗(yàn)內(nèi)容：設(shè)計(jì)一個(gè)一維濾波處理程序（1、分別做低通、高通、帶通、帶阻等理想濾波器進(jìn)行處理；2、窗函數(shù)）</p><p>

55、;<b>　　實(shí)驗(yàn)結(jié)果：</b></p><p>　　、一維信號(hào)理想濾波器</p><p><b>　?。?）、窗函數(shù)</b></p><p><b>　　程序：</b></p><p>　　一 維 理 想 濾 波 器 </p><p>　　%%%%%

56、%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p>　　% 一維信號(hào)濾波器設(shè)計(jì)</p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

57、%%%%%</p><p>　　function varargout = num4_1lvbo(varargin)</p><p>　　% Begin initialization code - DO NOT EDIT</p><p>　　gui_Singleton = 1;</p><p>　　gui_State = struct('

58、;gui_Name', mfilename, ...</p><p>　　'gui_Singleton', gui_Singleton, ...</p><p>　　'gui_OpeningFcn', @num4_1lvbo_OpeningFcn, ...</p><p>　　'gui_OutputFcn

59、', @num4_1lvbo_OutputFcn, ...</p><p>　　'gui_LayoutFcn', [] , ...</p><p>　　'gui_Callback', []);</p><p>　　if nargin && ischar(varargin{1})</p>&

60、lt;p>　　gui_State.gui_Callback = str2func(varargin{1});</p><p><b>　　end</b></p><p>　　if nargout</p><p>　　[varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:});&

61、lt;/p><p><b>　　else</b></p><p>　　gui_mainfcn(gui_State, varargin{:});</p><p><b>　　end</b></p><p>　　function num4_1lvbo_OpeningFcn(hObject, eventdat

62、a, handles, varargin)</p><p>　　handles.output = hObject;</p><p>　　guidata(hObject, handles);</p><p>　　function varargout = num4_1lvbo_OutputFcn(hObject, eventdata, handles) </p&g

63、t;<p>　　varargout{1} = handles.output;</p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p>　　% 全局變量說(shuō)明</p><p&g

64、t;　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p>　　% yuchu 用于存放信號(hào)FFT變換結(jié)果</p><p>　　% long 用于存放信號(hào)長(zhǎng)度</p><p>　　% ys

65、 用于存放原始信號(hào)</p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p>　　% 讀取原始信號(hào)并進(jìn)行預(yù)處理</p><p>　　%%%%%%%%%%%%%%%%%%%%

66、%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p>　　function bt_read_Callback(hObject, eventdata, handles)</p><p>　　[FileName,PathName] = uigetfile('*.csv') </p>&

67、lt;p><b>　　global ys</b></p><p>　　ys=csvread(FileName);</p><p>　　axes(handles.wave_ys);</p><p>　　plot(ys(:,1),ys(:,2)); </p><p><b>　　gri

68、d on;</b></p><p>　　axis([min(ys(:,1)) max(ys(:,1)) min(ys(:,2))*3/2 max(ys(:,2))*3/2]);</p><p>　　global yuchu </p><p>　　yuchu=fft(ys(:,2));</p>&l

69、t;p>　　global long </p><p>　　long=length(ys(:,2));</p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p>　　%

70、 低通濾波</p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p>　　function bt_dt_Callback(hObject, eventdata, handles)</p><p>　　

71、global yuchu long ys</p><p>　　f1=str2double(get(handles.input_f1,'string'));</p><p>　　for i=1:long</p><p>　　if i<=(fix(long/2)+1)*f1 || i>=(fix(long/2)+1)-(fix(long/2)

72、+1)*f1+...</p><p>　　(fix(long/2)+1)</p><p>　　dt(i)=yuchu(i);</p><p><b>　　else</b></p><p><b>　　dt(i)=0;</b></p><p><b>　　end<

73、;/b></p><p><b>　　end</b></p><p>　　ok=ifft(dt);</p><p>　　axes(handles.wave_dt);</p><p>　　plot(ys(:,1),ok);</p><p><b>　　grid on;</b&g

74、t;</p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p>　　% 高通濾波</p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

75、%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p>　　function bt_gt_Callback(hObject, eventdata, handles)</p><p>　　global yuchu long ys</p><p>　　f1=str2double(get(handles.input_f1,'str

76、ing'));</p><p>　　for i=1:long</p><p>　　if i<=(fix(long/2)+1)*f1 || i>=(fix(long/2)+1)-(fix(long/2)+1)*f1+...</p><p>　　(fix(long/2)+1)</p><p><b>　　gt(i)=

77、0;</b></p><p><b>　　else</b></p><p>　　gt(i)=yuchu(i);</p><p><b>　　end</b></p><p><b>　　end</b></p><p>　　ok=ifft(gt)

78、;</p><p>　　axes(handles.wave_gt);</p><p>　　plot(ys(:,1),ok);</p><p><b>　　grid on;</b></p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

79、%%%%%%%%%%%%%%</p><p>　　% 帶阻濾波</p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p>　　function bt_dz_Callback(hOb

80、ject, eventdata, handles)</p><p>　　global yuchu long ys</p><p>　　f1=str2double(get(handles.input_f1,'string'));</p><p>　　f2=str2double(get(handles.input_f2,'string')

81、);</p><p>　　for i=1:long</p><p>　　if (i>=(fix(long/2)+1)*f1 && i<=(fix(long/2)+1)*f2) || ...</p><p>　　(i<=(fix(long/2)+1)-(fix(long/2)+1)*f1+(fix(long/2)+1)...</

82、p><p>　　&& i>=(fix(long/2)+1)-(fix(long/2)+1)*f2+(fix(long/2)+1))</p><p><b>　　dz(i)=0;</b></p><p><b>　　else</b></p><p>　　dz(i)=yuchu(i);

83、</p><p><b>　　end</b></p><p><b>　　end</b></p><p>　　ok=ifft(dz);</p><p>　　axes(handles.wave_dz);</p><p>　　plot(ys(:,1),ok);</p>

84、<p><b>　　grid on;</b></p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p>　　% 帶通濾波</p><p>　　%

85、%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p>　　function bt_dat_Callback(hObject, eventdata, handles)</p><p>　　global yuchu long ys</p><p>　　f1=s

86、tr2double(get(handles.input_f1,'string'));</p><p>　　f2=str2double(get(handles.input_f2,'string'));</p><p>　　for i=1:long</p><p>　　if (i>=(fix(long/2)+1)*f1 &&

87、amp; i<=(fix(long/2)+1)*f2) || ...</p><p>　　(i<=(fix(long/2)+1)-(fix(long/2)+1)*f1+(fix(long/2)+1)...</p><p>　　&& i>=(fix(long/2)+1)-(fix(long/2)+1)*f2+(fix(long/2)+1))</p>

88、;<p>　　dz(i)=yuchu(i);</p><p><b>　　else</b></p><p><b>　　dz(i)=0;</b></p><p><b>　　end</b></p><p><b>　　end</b></

89、p><p>　　ok=ifft(dz);</p><p>　　axes(handles.wave_dat);</p><p>　　plot(ys(:,1),ok);</p><p><b>　　grid on;</b></p><p><b>　　窗 函 數(shù) </b></

90、p><p>　　function varargout = num4_windows(varargin)</p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p>　　% 本程序用于對(duì)一維信號(hào)進(jìn)行窗函數(shù)濾波</p><p&g

91、t;　　% 其中，f1、f2、f3、f4依次為</p><p>　　% 帶通濾波鑲邊后的四個(gè)頻率</p><p>　　% 為了使濾波效果較好，建議使 f1-f2=f3-f4</p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p>

92、<p>　　gui_Singleton = 1;</p><p>　　gui_State = struct('gui_Name', mfilename, ...</p><p>　　'gui_Singleton', gui_Singleton, ...</p><p>　　'gui_OpeningFcn

93、', @num4_windows_OpeningFcn, ...</p><p>　　'gui_OutputFcn', @num4_windows_OutputFcn, ...</p><p>　　'gui_LayoutFcn', [] , ...</p><p>　　'gui_Callback', [

94、]);</p><p>　　if nargin && ischar(varargin{1})</p><p>　　gui_State.gui_Callback = str2func(varargin{1});</p><p><b>　　end</b></p><p>　　if nargout</p

95、><p>　　[varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:});</p><p><b>　　else</b></p><p>　　gui_mainfcn(gui_State, varargin{:});</p><p><b>　　end&l

96、t;/b></p><p>　　function num4_windows_OpeningFcn(hObject, eventdata, handles, varargin)</p><p>　　handles.output = hObject;</p><p>　　guidata(hObject, handles);</p><p>

97、　　function varargout = num4_windows_OutputFcn(hObject, eventdata, handles) </p><p>　　varargout{1} = handles.output;</p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

98、%%%%%%</p><p>　　% 以下為信號(hào)讀取以及原始信號(hào)的繪制</p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p>　　function read_Callback(hObject, e

99、ventdata, handles)</p><p>　　[FileName,PathName] = uigetfile('*.csv') % read file </p><p>　　global sign</p><p>　　sign=csvread(FileName);</p><p>　　axes(handles

100、.axes_sign)</p><p>　　plot(1:length(sign'),sign(:,2))</p><p><b>　　grid on</b></p><p>　　function plot_Callback(hObject, eventdata, handles)</p><p>　　% 采樣頻

101、率100Hz，Wpl=20Hz，Wph=30Hz，Wsl=15Hz，Wsh=35Hz，</p><p>　　% 頻率/采樣頻率*2*pi</p><p>　　% Wpl=0.4*pi，Wph=0.6*pi，Wsl=0.2*pi，Wsh=0.8*pi，</p><p>　　% Rp=1;As=20</p><p><b>　　clc;

102、</b></p><p>　　T = 1; Fs = 1/T; % Set T=1</p><p>　　%%%%%%%%%%%%%%%%%%%%%按照比值進(jìn)行帶通的四個(gè)頻率成份的界定 %%%%%%%%%%%%%%%%%%%%</p><p>　　f1=str2double(get(handles.input_f1,'string'));&

103、lt;/p><p>　　f2=str2double(get(handles.input_f2,'string'));</p><p>　　f3=str2double(get(handles.input_f3,'string'));</p><p>　　f4=str2double(get(handles.input_f4,'stri

104、ng'));</p><p>　　%--------------------------------------------------------------------------</p><p>　　global sign</p><p>　　kk=length(sign'); % 一維信號(hào)長(zhǎng)度</p><p>

105、　　Wpl=tan(f2/2/Fs*pi);</p><p>　　Wph=tan(f3/2/Fs*pi);</p><p>　　Wsl=tan(f1/2/Fs*pi);</p><p>　　Wsh=tan(f4/2/Fs*pi);</p><p><b>　　Rp = 1;</b></p><p>

106、;<b>　　As= 40;</b></p><p>　　% 計(jì)算模擬低通原型的參數(shù)</p><p>　　OmigaP=Wph-Wpl; % 低通濾波器通帶截止頻率</p><p>　　OmigaS=Wsh-Wsl; % 低通濾波器通帶截止頻率</p><p>　　[N,Wn]=buttord(OmigaP,OmigaS

107、,Rp,As,'s');</p><p>　　[B,A]=butter(N,Wn,'s');</p><p>　　[BT,AT]=lp2bp(B,A,sqrt(Wph*Wpl),Wph-Wpl);</p><p>　　[b,a]=bilinear(BT,AT,Fs);</p><p>　　H=freqz(b,a

108、,kk,'whole');</p><p>　　axes(handles.axes_ifft) % 輸出濾波器</p><p>　　plot(1:kk,ifft(abs(H).*fft(sign(:,2))),'r');</p><p><b>　　grid on;</b></p><p&g

109、t;　　axes(handles.axes_fft) % 輸出濾波后的信號(hào)</p><p>　　plot(abs(H),'r');</p><p><b>　　grid on;</b></p><p>　　六、驗(yàn)證褶積性質(zhì)（設(shè)計(jì)4）</p><p>　　設(shè)計(jì)內(nèi)容：驗(yàn)證時(shí)間域的循環(huán)褶積對(duì)應(yīng)的是頻率域的乘

110、積；線(xiàn)性褶積則不然。</p><p><b>　　實(shí)驗(yàn)結(jié)果：</b></p><p>　　a，b兩向量取如下值：a=[1,2,3,4]; b=[1,2,3];</p><p><b>　　計(jì)算得到如下結(jié)果：</b></p><p>　　當(dāng)循環(huán)次數(shù)依次為4，5，6，7時(shí)，在頻率域和時(shí)間域計(jì)算得到的循

111、環(huán)褶積均相等；</p><p>　　當(dāng)循環(huán)次數(shù)小于6（N1+N2-1）時(shí)，時(shí)間域和頻率域計(jì)算所得的結(jié)果不同，但是當(dāng)循環(huán)次數(shù)大于6時(shí)，兩種方法計(jì)算得到的結(jié)果相等。</p><p>　　因此可以得到如下結(jié)論:</p><p>　　兩個(gè)向量的循環(huán)褶積所對(duì)應(yīng)的頻譜是兩信號(hào)各自頻譜在頻率域的乘積；</p><p>　　當(dāng)兩個(gè)向量在頻率域計(jì)算線(xiàn)性褶積時(shí)，

112、要對(duì)兩個(gè)信號(hào)進(jìn)行補(bǔ)零擴(kuò)展，使兩個(gè)信號(hào)同大小。當(dāng)擴(kuò)展出的新信號(hào)長(zhǎng)度小于臨界長(zhǎng)度6（N1+N2-1）時(shí)，頻率域和時(shí)間域計(jì)算得到的線(xiàn)性褶積不相等；當(dāng)擴(kuò)展出的新信號(hào)長(zhǎng)度大于等于臨界長(zhǎng)度6（N1+N2-1）時(shí)，頻率域和時(shí)間域計(jì)算得到的線(xiàn)性褶積相等。</p><p>　　例如：設(shè)length(a)=n1 length(b)=n2 length(新信號(hào))=n3</p><p>　　如果 n3&

113、lt;n1+n2-1 兩種方法所得結(jié)果不等；</p><p>　　如果 n3>=n1+n2-1 兩種方法所得結(jié)果相等；</p><p><b>　　程序： </b></p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

114、%%%%%%%%%%%</p><p>　　% 驗(yàn)證時(shí)間域的循環(huán)褶積對(duì)應(yīng)的是頻率域的乘積；線(xiàn)性褶積則不然。</p><p>　　%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p><b>　　clear;</b><

115、;/p><p><b>　　clc;</b></p><p>　　a=[1,2,3,4];</p><p>　　b=[1,2,3];</p><p>　　kk1=length(a);</p><p>　　kk2=length(b);</p><p>　　'臨界循環(huán)次數(shù)（

116、循環(huán)=線(xiàn)性）'</p><p>　　minl=length(a)+length(b)-1 % 臨界循環(huán)次數(shù)（循環(huán)=線(xiàn)性）</p><p><b>　　'循環(huán)次數(shù)'</b></p><p>　　xx=4 % 循環(huán)次數(shù) 手動(dòng)更改 >=max(length(a),l

117、ength(b))</p><p>　　aa=zeros(xx,1);</p><p>　　aa(1:kk1,1)=a'; % 擴(kuò)展a</p><p>　　bb=zeros(xx,1);</p><p>　　bb(1:kk2,1)=b'; % 擴(kuò)展b</p>

118、<p>　　bb1=zeros(xx,xx); % 循環(huán)矩陣</p><p>　　for i=1:xx</p><p>　　bb1(i:xx,i)=bb(1:xx-i+1);</p><p>　　bb1(1:i-1,i)=bb(xx-i+2:xx);</p><p><b>　　end</b

119、></p><p>　　'時(shí)間域計(jì)算循環(huán)褶積結(jié)果'</p><p>　　ok1=bb1*aa % 時(shí)間域計(jì)算循環(huán)褶積結(jié)果</p><p>　　'頻率域計(jì)算循環(huán)褶積結(jié)果'</p><p>　　ok2=ifft(fft(aa).*fft(bb)) % 頻率域計(jì)算循環(huán)褶積

120、結(jié)果</p><p><b>　　'作差比較'</b></p><p>　　plus1=ok1-ok2 % 作差比較</p><p>　　'時(shí)間域計(jì)算線(xiàn)性褶積結(jié)果'</p><p>　　ok3=conv(a,b) % 時(shí)間域計(jì)

121、算線(xiàn)性褶積結(jié)果</p><p><b>　　kk=5</b></p><p>　　aa=zeros(kk,1);</p><p>　　aa(1:kk1,1)=a'; % 擴(kuò)展a</p><p>　　bb=zeros(kk,1);</p><p>　　bb(1:k

122、k2,1)=b'; </p><p>　　'頻率域計(jì)算線(xiàn)性褶積結(jié)果'</p><p>　　ok4=ifft(fft(aa).*fft(bb)) % 頻率域計(jì)算線(xiàn)性褶積結(jié)果</p><p>　　ok33=zeros(length(ok3)+length(ok4),1);</p><p>　　ok33(1:lengt

123、h(ok3),1)=ok3;</p><p>　　ok44=zeros(length(ok3)+length(ok4),1);</p><p>　　ok44(1:length(ok4),1)=ok4;</p><p><b>　　'作差比較'</b></p><p>　　plus2=ok33-ok44

124、 % 作差比較</p><p><b>　　七、實(shí)習(xí)感想</b></p><p>　　通過(guò)這次的計(jì)算機(jī)編程與數(shù)字信號(hào)處理實(shí)習(xí)，使我對(duì)數(shù)字信號(hào)處理的了解有了很大的提高。老師生動(dòng)細(xì)致的講解和悉心輔導(dǎo)讓人印象深刻。在此，首先要對(duì)老師的指導(dǎo)致以深深的謝意。</p><p>　　剛剛開(kāi)始的時(shí)候，我感覺(jué)對(duì)MATLAB比較生疏，編程時(shí)