数字信号处理matlab课程设计.doc

课题一数字信号处理系统设计1、 项目要求用本课程所学的数字信号处理理论知识，设计一个具有信号的采集、处理、传输、显示和存储等功能的系统，内容如下：、 录制一段语音信号，并对录制的语音信号进行采样（采样频率可取fs=22050Hz）;、 画出采样后的语音信号的时域波形和频谱图；、 滤波器的性能指标：低通滤波器：通带边界频率，通带最大衰减B；阻带边界频率.2，阻带最小衰减00B；高通滤波器：通带边界频率5，通带最大衰减B；阻带边界频率4.8，阻带最小衰减00B；带通滤波器：通带上限截止频率fp2=3kHz, 通带下限截止频率fp1=1.2kHz; 阻带上限截止频率fs2=3.2kHz, 通带下限截止频率fp1=1kHz; 通带最大衰减Ap=1dB, 阻带最小衰减As=100dB;采用双线性变换法设计滤波器，并画出滤波器的频率响应；、 用自己设计的滤波器对采样的信号进行滤波，画出滤波后信号的时域波形和频谱图，并对滤波前后的信号进行对比，分析信号的变化；、 回放语音、 用设计一个信号系统的用户界面。二、实验所要用到的函数、语音信号的采样与播放wavread();y，fs，bite=wavread（）；%语音信号的采样sound（y，fs，bite）；%播放语音2. 滤波器：IIR：butte（）；%巴特沃思滤波器 cheby1();%切比雪夫I滤波器 elliptical（）；%椭圆滤波器3. 频率响应：h，f=freqz（b,a,n,fs）freqz(b,a,n,fs)5. 快速傅里叶变换fft (x, n)6. 画曲线plot(x, y)stem(x, y)7. 在MATLAB中，设计辅助低通原型巴特沃思和切比雪夫滤波器的阶数和截止频率；1） 利用buttord和cheblord确定阶数；2） num，den=butter（N，Wn），num，den=cheby1（N，Wn）3） lp2hp,lp2bp,lp2bs可以完成低通滤波器到高通，带通，带阻的转换4） 使用biliner对模拟滤波器进行双线性变换，求得数字滤波器的传输函数系数3、 数字滤波器（代码）1. IIR低通滤波器fp=1000;ft=5500;fs=1200;wp=2*pi*fp/ft;ws=2*pi*fs/ft;Fp=2*ft*tan(wp/2);Fs=2*ft*tan(ws/2);n,Omgc=buttord(Fp,Fs,1,100,s); z,p,k=buttap(n);B=k*real(poly(z);A=real(poly(p);b1,a1=lp2lp(B,A,Omgc);ba1,aa1=bilinear(b1,a1,ft); %模拟转数字Ha,w=freqz(ba1,aa1); %求频率相应plot(w*ft/(2*pi),20*log10(abs(Ha);title(IIR 低通滤波器);xlabel(频率/HZ);ylabel(幅值);2. IIR高通滤波器fp=5000;ft=25000;%取抽样频率fs=4800;Rp=1;As=100;wp=2*pi*fp/ft;%通带频率ws=2*pi*fs/ft;%截止频率Fp=2*ft*tan(wp/2);Fs=2*ft*tan(ws/2);n,Omgc=ellipord(Fp,Fs,Rp,As,s); %计算阶数n和截止频率z,p,k=ellipap(n,Rp,As);B3=k*real(poly(z);A3=real(poly(p);b3,a3=lp2hp(B3,A3,Omgc);ba3,aa3=bilinear(b3,a3,ft);Ha,w=freqz(ba3,aa3);plot(w*ft/(2*pi),20*log10(abs(Ha);title(IIR高通滤波器);xlabel(频率/HZ);ylabel(幅值);3. IIR带通滤波器fp1=1200;fp2=3000;fs1=1000;fs2=3200;ft=10000;As=100;Rp=1;wp1=2*pi*fp1/ft;wp2=2*pi*fp2/ft;ws1=2*pi*fs1/ft;ws2=2*pi*fs2/ft;Fp1=2*ft*tan(wp1/2);Fp2=2*ft*tan(wp2/2);Fp=Fp1,Fp2;Fs1=2*ft*tan(ws1/2);Fs2=2*ft*tan(ws2/2);Fs=Fs1,Fs2;bw=Fp2-Fp1;w0=sqrt(Fp1*Fp2);%通带宽和中心频率n,Omgn=cheb1ord(Fp,Fs,Rp,As,s);z,p,k=cheb1ap(n,Rp);B2=k*real(poly(z);A2=real(poly(p);b2,a2=lp2bp(B2,A2,w0,bw);ba2,aa2=bilinear(b2,a2,ft);Ha,w=freqz(ba2,aa2);plot(w*ft/(2*pi),20*log10(abs(Ha);title(IIR 带通滤波器);xlabel(频率/HZ);ylabel(幅值);4、 总代码function varargout = bzh(varargin)% BZH M-file for bzh.fig% BZH, by itself, creates a new BZH or raises the existing% singleton*.% H = BZH returns the handle to a new BZH or the handle to% the existing singleton*.% BZH(CALLBACK,hObject,eventData,handles,.) calls the local% function named CALLBACK in BZH.M with the given input arguments.% BZH(Property,Value,.) creates a new BZH or raises the% existing singleton*. Starting from the left, property value pairs are% applied to the GUI before ko_OpeningFunction gets called. An% unrecognized property name or invalid value makes property application% stop. All inputs are passed to bzh_OpeningFcn via varargin.% *See GUI Options on GUIDEs Tools menu. Choose GUI allows only one% instance to run (singleton).% See also: GUIDE, GUIDATA, GUIHANDLES % Copyright 2002-2003 The MathWorks, Inc. % Edit the above text to modify the response to help bzh % Last Modified by GUIDE v2.5 09-Jan-2014 08:54:22 % Begin initialization code - DO NOT EDITgui_Singleton = 1;gui_State = struct(gui_Name, mfilename, . gui_Singleton, gui_Singleton, . gui_OpeningFcn, bzh_OpeningFcn, . gui_OutputFcn, bzh_OutputFcn, . gui_LayoutFcn, , . gui_Callback, );if nargin & ischar(varargin1) gui_State.gui_Callback = str2func(varargin1);end if nargout varargout1:nargout = gui_mainfcn(gui_State, varargin:);else gui_mainfcn(gui_State, varargin:);end% End initialization code - DO NOT EDIT % - Executes just before bzh is made visible.function bzh_OpeningFcn(hObject, eventdata, handles, varargin)% This function has no output args, see OutputFcn.% hObject handle to figure% eventdata reserved - to be defined in a future version of MATLAB% handles structure with handles and user data (see GUIDATA)% varargin command line arguments to bzh (see VARARGIN) % Choose default command line output for bzhhandles.output = hObject; % Update handles structureguidata(hObject, handles); % UIWAIT makes bzh wait for user response (see UIRESUME)% uiwait(handles.figure1); % - Outputs from this function are returned to the command line.function varargout = bzh_OutputFcn(hObject, eventdata, handles) % varargout cell array for returning output args (see VARARGOUT);% hObject handle to figure% eventdata reserved - to be defined in a future version of MATLAB% handles structure with handles and user data (see GUIDATA) % Get default command line output from handles structurevarargout1 = handles.output; % - Executes on button press in tag_start.function tag_start_Callback(hObject, eventdata, handles)% hObject handle to tag_start (see GCBO)% eventdata reserved - to be defined in a future version of MATLAB% handles structure with handles and user data (see GUIDATA)axes(handles.axes1)cla;global z0;global yy;fs=22050;nbits=32;yy,fs,nbits=wavread(D:f.wav); %语音信号加载sound(yy,fs); %回放语音z0=yy;axes(handles.axes1);plot(yy);title(时域采样信号波形);grid onn=length(yy); %求出语音信号的长度Y=fft(yy,n); %傅里叶变换axes(handles.axes2);plot(20*log10(abs(Y);title(时域采样信号频谱);guidata(hObject,handles);grid on % - Executes on button press in tag_ditong.function tag_ditong_Callback(hObject, eventdata, handles)% hObject handle to tag_ditong (see GCBO)% eventdata reserved - to be defined in a future version of MATLAB% handles structure with handles and user data (see GUIDATA)axes(handles.axes1)cla;global z1;global yy;global ba1;global aa1;global Fp;global Fs;fp=1000;ft=5500;fs=1200;wp=2*pi*fp/ft;ws=2*pi*fs/ft;Fp=2*ft*tan(wp/2);Fs=2*ft*tan(ws/2);n,Omgc=buttord(Fp,Fs,1,100,s); z,p,k=buttap(n);B=k*real(poly(z);A=real(poly(p);b1,a1=lp2lp(B,A,Omgc);ba1,aa1=bilinear(b1,a1,ft); %模拟转数字z1=filter(ba1,aa1,yy);Ha,w=freqz(ba1,aa1); %求频率相应plot(w*ft/(2*pi),20*log10(abs(Ha);title(IIR 低通滤波器);xlabel(频率/HZ);ylabel(幅值); % - Executes on button press in tag_gaotong.function tag_gaotong_Callback(hObject, eventdata, handles)% hObject handle to tag_gaotong (see GCBO)% eventdata reserved - to be defined in a future version of MATLAB% handles structure with handles and user data (see GUIDATA)axes(handles.axes2)cla;global yy;global z2;global B3;global ba3;global aa3;global Fp;global Fs;fp=5000;ft=25000;%取抽样频率fs=4800;Rp=1;As=100;wp=2*pi*fp/ft;%通带频率ws=2*pi*fs/ft;%截止频率Fp=2*ft*tan(wp/2);Fs=2*ft*tan(ws/2);n,Omgc=ellipord(Fp,Fs,Rp,As,s); %计算阶数n和截止频率z,p,k=ellipap(n,Rp,As);B3=k*real(poly(z);A3=real(poly(p);b3,a3=lp2hp(B3,A3,Omgc);ba3,aa3=bilinear(b3,a3,ft);z2=filter(ba3,aa3,yy);Ha,w=freqz(ba3,aa3);plot(w*ft/(2*pi),20*log10(abs(Ha);title(IIR高通滤波器);xlabel(频率/HZ);ylabel(幅值);% - Executes on button press in tag_daitong.function tag_daitong_Callback(hObject, eventdata, handles)% hObject handle to tag_daitong (see GCBO)% eventdata reserved - to be defined in a future version of MATLAB% handles structure with handles and user data (see GUIDATA)axes(handles.axes3)cla;global yy;global z3;global B2;global ba2;global aa2;fp1=1200;fp2=3000;fs1=1000;fs2=3200;ft=10000;As=100;Rp=1;wp1=2*pi*fp1/ft;wp2=2*pi*fp2/ft;ws1=2*pi*fs1/ft;ws2=2*pi*fs2/ft;Fp1=2*ft*tan(wp1/2);Fp2=2*ft*tan(wp2/2);Fp=Fp1,Fp2;Fs1=2*ft*tan(ws1/2);Fs2=2*ft*tan(ws2/2);Fs=Fs1,Fs2;bw=Fp2-Fp1;w0=sqrt(Fp1*Fp2);%通带宽和中心频率n,Omgn=cheb1ord(Fp,Fs,Rp,As,s);z,p,k=cheb1ap(n,Rp);B2=k*real(poly(z);A2=real(poly(p);b2,a2=lp2bp(B2,A2,w0,bw);ba2,aa2=bilinear(b2,a2,ft);z3=filter(ba2,aa2,yy);Ha,w=freqz(ba2,aa2);plot(w*ft/(2*pi),20*log10(abs(Ha);title(IIR 带通滤波器);xlabel(频率/HZ);ylabel(幅值); % - Executes on button press in tag_dibo.function tag_dibo_Callback(hObject, eventdata, handles)% hObject handle to tag_dibo (see GCBO)% eventdata reserved - to be defined in a future version of MATLAB% handles structure with handles and user data (see GUIDATA)axes(handles.axes3)cla;global yy;global z1;global ba1;global aa1;m4=fft(z1);plot(z1,y);title(IIR滤波后的信号波形);xlabel(时间/t);ylabel(幅值);axes(handles.axes4)cla;plot(abs(m4),y);title(IIR滤波后信号频谱);xlabel(频率/HZ);ylabel(幅值);% - Executes on button press in tag_gaobo.function tag_gaobo_Callback(hObject, eventdata, handles)% hObject handle to tag_gaobo (see GCBO)% eventdata reserved - to be defined in a future version of MATLAB% handles structure with handles and user data (see GUIDATA)axes(handles.axes3)cla;global yy;global z2;global B3;global ba3;global aa3;m5=fft(z2);plot(z2,y);title(IIR滤波后的信号波形);xlabel(时间/t);ylabel(幅值);axes(handles.axes4)cla;plot(abs(m5),y);title(IIR滤波后信号频谱);xlabel(频率/HZ);ylabel(幅值);% - Executes on button press in tag_daibo.function tag_daibo_Callback(hObject, eventdata, handles)% hObject handle to tag_daibo (see GCBO)% eventdata reserved - to be defined in a future version of MATLAB% handles structure with handles and user data (see GUIDATA)axes(handles.axes3)cla;global yy;global z3;global B2;global ba2;global aa2;m6=fft(z3);plot(z3,y);title(IIR滤波后的信号波形);xlabel(时间/t);ylabel(幅值);axes(handles.axes4)cla;plot(abs(m6),y);title(IIR滤波后信号频谱);xlabel(频率/HZ);ylabel(幅值); % - Executes on selection change in tag_choose.function tag_choose_Callback(hObject, eventdata, handles)% hObject handle to tag_choose (see GCBO)% eventdata reserved - to be defined in a future version of MATLAB% handles structure with handles and user data (see GUIDATA) % Hints: contents = get(hObject,String) returns tag_choose contents as cell array% contentsget(hObject,Value) returns selected item from tag_choose % - Executes during object creation, after setting all properties.function tag_choose_CreateFcn(hObject, eventdata, handles)% hObject handle to tag_choose (see GCBO)% eventdata reserved - to be defined in a future version of MATLAB% handles empty - handles not created until after all CreateFcns called % Hint: popupmenu controls usually have a white background on Windows.% See ISPC and COMPUTER.if ispc set(hObject,BackgroundColor,white);else set(hObject,BackgroundColor,get(0,defaultUicontrolBackgroundColor);end % - Executes on button press in tag_return.function tag_return_Callback(hObject, event