课程设计-基于MATLAB的语音信号分析与处理的课程设计实验报告.doc

目 录绪论1正文：一、设计目的及要求2二、设计过程2三、调试分析6四、结果分析与体会11五、参考文献12六、谢辞12绪 论数字信号处理（digital signal processing,DSP）是从20世纪60年代以来，随着信息学科和计算机学科的高速发展而迅速发展起来的一门新兴学科。它的重要性日益在各个领域的应用中表现出来。简言之，数字信号处理是把信号用数字或符号表示的序列，通过计算机或通用（专用）信号处理设备，用数字的数值计算方法处理（例如滤波、变换、压缩、增强、估计、识别等），以达到提取有用信息便于应用的目的。数字信号处理的应用包括滤波与变换、通信、语音、语言、图像、图形、消费电子、仪器、工业控制与自动化、医疗、军事等。其发展方向也是多方面的，包括数字汇聚、远程会议系统、融合网络、数字图书馆、图像与文本合一的信息检索业务、多媒体通信、个人信息终端等。在本次设计中，就以设计一个数字滤波器系统为目的。滤波器按频率划分有低通、高通、带通、带阻全通等类型。一个数字滤波器可以用一个系统函数来表示，若要得到该系统函数，就要得到以z(-1)升幂排列的传输函数的分子和分母多项式的系数，即向量num、den，而这两个参数由num den=butter(N,Wn)、N,Wn=buttord(wp,ws,rp,rs)这一函数得出，这是巴特沃思滤波器的设计过程。由于频率响应的周期性，频率变量以数字频率来表示，=2*f/fc，f为模拟域频率，fc为抽样频率，所以数字滤波器设计中必须给出抽样频率。在这次设计中采用了巴特沃思和切比雪夫两种滤波器，这两种滤波器又分别采用了高通、低通、带通、带阻四种频率特性实现，从横向上和纵向上都可以进行对比，表现出各种滤波器的不同特性。 一、设计目的及要求1课程设计目的 综合运用数字信号处理的理论知识进行频谱分析和滤波器设计，通过理论推导得出相应结论，再利用 MATLAB 作为编程工具进行计算机实现，从而加深对所学知识的理解，建立概念。2课程设计基本要求 1） 学会 MATLAB 的使用，掌握 MATLAB 的程序设计方法。 2） 掌握在 Windows 环境下语音信号采集的方法。 3） 掌握数字信号处理的基本概念、基本理论和基本方法。 4） 掌握 MATLAB 设计 FIR 和IIR 数字滤波器的方法。 5） 学会用 MATLAB 对信号进行分析和处理。3课程设计内容录制一段自己的语音信号，并对录制的信号进行采样；画出采样后语音信号的时域波形和频谱图；给定滤波器的性能指标，设计数字滤波器，并画出滤波器的频率响应；然后用自己设计的滤波器对采集的语音信号进行滤波，画出滤波后信号的时域波形和频谱，并对滤波前后的信号进行对比，分析信号的变化；回放语音信号；最后，用 MATLAB 设计一信号处理系统界面。二、设计过程1、 打开GUI窗口：File New GUI Create New GUI Blank GUI(Default) OK2、 控件设计：在控件布局设计区放置四个Axes控件、六个Push Button控件、一个Button Group控件和两个Radio Button控件、四个Static Text控件。3、 修改控件属性：选中需要修改属性的控件，双击打开属性查看器，具体设置如下：1) 五个Axes控件 Tag作用axes1提供坐标画出原始信号波形axes2提供坐标画出原始信号频谱axes3提供坐标画出滤波后信号波形axes4提供坐标画出滤波后信号频谱axes5提供坐标画出滤波器频率响应2) 六个Push Button控件：StringTagStringTag低通pushbutton1带阻pushbutton4高通pushbutton2原始信号pushbutton5带通pushbutton3关闭窗口pushbutton63) 一个Button Group控件和两个Radio Button控件： StringStyleTag请选择滤波器种类Button Groupuipanel5巴特沃思Radio Buttonradiobutton1切比雪夫Radio Buttonradiobutton24) 五个Static Text控件（这五个Static Text控件是对坐标轴中图形的说明）：TagStringtext1原始信号波形text2原始信号频谱text3滤波后信号波形text4滤波后信号频谱text5滤波器频率响应4、 保存：设置好各个控件的属性，回到GUI主窗口保存，给文件命名为hy，同时hy.m文件打开。5、 设置回调函数：在hy.m文件窗口中设置回函数。这里，虽然GUI自动生成了回调函数，但是回调函数是空的，需要在hy.m文件中对它进行定义说明。该程序只需要对六个Push Button控件的回调函数进行定义说明。六个Push Button控件的回调函数：1）“低通”按键的回调函数function pushbutton1_Callback(hObject, eventdata, handles)y,fs,bits=wavread(e:hy.wav); %函数wavread是对语音信号进行 采样，格式是y,fs,nbit=wavread，返回采样值放在向量y中，fs表示采样频率（Hz），nbit表示采样位数。fp=1000;fs=2000;rp=0.5;rs=40;fc=40000;%设定通带截止频率（fp）、阻带截止频率（fs）、通带波纹系数（rp）、阻带波纹系数（rs）、抽样频率（fc）。wp=2*fp/fc;ws=2*fs/fc; %将模拟域转化成数字域。if get(handles.radiobutton1,value) %如果选择radiobutton1，则制做巴特沃思滤波器。N,Wc=buttord(wp,ws,rp,rs); %估算巴特沃思滤波器的阶数N和3dB截止频率Wc。num,den=butter(N,Wc); %求传输函数的分子和分母多项式的系数。else %选择radiobutton2，则制做切比雪夫型滤波器。N,Wc=cheb1ord(wp,ws,rp,rs); %估算切比雪夫型滤波器的阶数N和截止频率Wc。num,den=cheby1(N,rp,Wc); %求传输函数的分子和分母多项式的系数。endx=filter(num,den,y); %根据传输函数的分子和分母多项式的系数得到模拟滤波器，并将y通过该滤波器，得到x。sound(x,fc,bits); %将滤波后的信号x进行回放。X=fft(x); %将x信号进行快速傅里叶变换。axes(handles.axes3);plot(x); %在axes3坐标轴上画出x信号的波形图。axes(handles.axes4);plot(abs(X); %在axes4坐标轴上画出x信号的频谱图。h,f=freqz(num,den,256,fc); %求滤波器的频率响应。axes(handles.axes5);plot(f,abs(h),k); %在axes5坐标轴上以黑线画出滤波器的频率响应。2）“高通”按键的回调函数function pushbutton2_Callback(hObject, eventdata, handles)y,fs,bits=wavread(e:hy.wav);fp=2000;fs=1000;rp=0.5;rs=40;fc=40000;wp=2*fp/fc;ws=2*fs/fc;if get(handles.radiobutton1,value)N,Wc=buttord(wp,ws,rp,rs);num,den=butter(N,Wc,high); %返回N阶高通滤波器。else N,Wc=cheb1ord(wp,ws,rp,rs);num,den=cheby1(N,rp,Wc,high);endx=filter(num,den,y);sound(x,fc,bits);X=fft(x);axes(handles.axes3);plot(x);axes(handles.axes4);plot(abs(X);h,f=freqz(num,den,256,fc);axes(handles.axes5);plot(f,abs(h),k);3）“带通”按键的回调函数function pushbutton3_Callback(hObject, eventdata, handles)y,fs,bits=wavread(e:hy.wav);fp=3000,8000;fs=1000,10000;rp=0.5;rs=40;fc=40000;wp=2*fp/fc;ws=2*fs/fc;if get(handles.radiobutton1,value)N,Wc=buttord(wp,ws,rp,rs);num,den=butter(N,Wc); %Wc为双元素向量，返回2N阶带通滤波器。else N,Wc=cheb1ord(wp,ws,rp,rs);num,den=cheby1(N,rp,Wc);endx=filter(num,den,y);sound(x,fc,bits);X=fft(x);axes(handles.axes3);plot(x);axes(handles.axes4);plot(abs(X);h,f=freqz(num,den,256,fc);axes(handles.axes5);plot(f,abs(h),k);4）“带阻”按键的回调函数function pushbutton4_Callback(hObject, eventdata, handles)y,fs,bits=wavread(e:hy.wav);fp=1000,10000;fs=3000,8000;rp=0.5;rs=40;fc=40000;wp=2*fp/fc;ws=2*fs/fc;if get(handles.radiobutton1,value)N,Wc=buttord(wp,ws,rp,rs);num,den=butter(N,Wc,stop); %返回2N阶带阻滤波器。else N,Wc=cheb1ord(wp,ws,rp,rs);num,den=cheby1(N,rp,Wc,stop);endx=filter(num,den,y);sound(x,fc,bits);X=fft(x);axes(handles.axes3);plot(x);axes(handles.axes4);plot(abs(X);h,f=freqz(num,den,256,fc);axes(handles.axes5);plot(f,abs(h),k);5）“原始信号”按键的回调函数function pushbutton5_Callback(hObject, eventdata, handles)y,fs,bits=wavread(e:hy.wav);sound(y,fs,bits);Y=fft(y);axes(handles.axes1);plot(y);axes(handles.axes2);plot(abs(Y);6）“关闭窗口”按键的回调函数function pushbutton6_Callback(hObject, eventdata, handles)close6、 保存修改后的hy.m文件，单击GUI主窗口工具栏中的“激活运行”按钮，在GUI界面中按下“原始信号”按键就可以看到原始信号的波形和频谱，并播放原始信号；选择滤波器种类（巴特沃思或切比雪夫），然后按下“高通”、“低通”、“带通”、“带阻”其中一个按键，就可以看到原信号经过滤波器后的信号的波形与频谱，并播放该信号。三、调试分析图1 控件布局图2 单击“激活运行”后界面图3 巴特沃思高通滤波器图4 切比雪夫高通滤波器图5 巴特沃思低通滤波器图6 切比雪夫低通滤波器 图7 巴特沃思带通滤波器 图8 切比雪夫带通滤波器 图9 巴特沃思带阻滤波器图10 切比雪夫带阻滤波器图3图10为巴特沃思和切比雪夫型滤波器在不同频率特性下产生的信号波形与频谱，同时有原信号作对比。可以看出，巴特沃思滤波器的频率特性曲线无论在通带还是在阻带内，都是频率的单调函数，切比雪夫型滤波器的幅频特性在通带内是等波纹的，阻带内是单调的。因为在回调函数中，高通和低通、带通和带阻滤波器的截止频率、波纹系数、抽样频率设定的值是相同的，所以在下图中纵向对比可以看出，信号通过高通和低通滤波器之后频谱相对于原信号是互补的，如果对于高通滤波器在某一频率段上有幅值，那么对于低通滤波器该频率幅值为零。同理于带通和带阻滤波器。横向上对比可以看出不同滤波器选频特性也不同，特别是在图7图10中选频边界处的频谱处理可以看出，切比雪夫滤波器比巴特沃思滤波器的选频特性好。四、结果分析与体会滤波器的作用就是滤除掉阻带内有频率分量，保留通带内的频率分量。在图3图10的波形图和频谱图中可以看出，经过滤波器处理后，不仅滤除掉了原信号的部分频率分量，原信号的幅度也会有所衰减，而低通和带阻滤波器产生的信号相对于原信号变化不大，是因为设定的选频范围是原信号的频率段中较集中的部分，所以与此同时，高通和带通滤波器产生的信号相对于原信号的幅度就会大大衰减，其原因也是在于高通和带通滤波器的选频范围是原信号频率范围中较少的一部分。在信号回放时，低通和带阻滤波器回放的音频信号与原信号相比，音色有一点低沉；而高通和带通滤波器回放的音频信号，几乎已经听不到什么声音，这也说明了这两种滤波器产生的信号频率只占原信号频率范围中较少的部分。所以根据各个滤波器的选频范围及滤波后信号的音效，可大致判断原信号的频率多集中在1000Hz以下。通过这次课设，使我对滤波器有了更深的认识，特别是滤波器参数对滤波器性能的影响，因为通带截止频率、阻带截止频率、通带波纹系数、阻带波纹系数都是要影响滤波器的阶数，而滤波器的阶数越大，其选频特性就越好。因为滤波器处理的音频信号是我自己的声音，所以通过滤波器处理后音频信号的变化，能大致得出自己声音的频率范围，也是挺有意思的。在做课程设计之前觉得内容挺难的，但经过查阅图书馆的资料和同学们的努力与帮助，最后还是以比较短的时间完成了这次课程设计。以前学MATLAB的时候，最后的大作业也是用GUI设计了一个可视化界面，所以在本次设计中可视化界面的设计也没有觉得很难。但是看到其他同学有用到Edit Text控件来作滤波器参数的输入，感觉到自己的能力还是很有限，所以还需要加强学习。但最重要的还是感觉到通过课程设计能够学以致用，并且运用以前学过的工具来更好的理解所学的内容，收获还是挺大的。五、参考文献程佩青 数字信号处理教程（第三版） 清华大学出版社罗军辉、罗勇江、白义臣等 MATLAB7.0在数字信号处理中的应用 机械工业出版社刘波、文忠、曾涯等 MATLAB信号处理 电子工业出版社六、谢辞在本次设计中，借阅了图书馆的一些书籍，比自己的帮助比较大，同学间的相互讨论与帮助也起到了很重要的作用。此外还要特别感谢指导老师耐心的辅导，并帮助我纠正错误，授予以鱼，亦之以渔，使我不仅能够按时完成课程设计，也从中对本课程有了更深的认识与理解，同时也注意到自己在学习方法中的不足，并会在日后加以改正。g an employment tribunal claimEmployment tribunals sort out disagreements between employers and employees.You may need to make a claim to an employment tribunal if: you dont agree with the disciplinary action your employer has taken against you your employer dismisses you and you think that you have been dismissed unfairly.For more information about dismissal and unfair dismissal, seeDismissal.You can make a claim to an employment tribunal, even if you haventappealedagainst the disciplinary action your employer has taken against you. However, if you win your case, the tribunal may reduce any compensation awarded to you as a result of your failure to appeal.Remember that in most cases you must make an application to an employment tribunal within three months of the date when the event you are complaining about happened. If your application is received after this time limit, the tribunal will not usually accept it.If you are worried about how the time limits apply to you, take advice from one of the organisations listed underFurther help.Employment tribunals are less formal than some other courts, but it is still a legal process and you will need to give evidence under an oath or affirmation.Most people find making a claim to an employment tribunal challenging. If you are thinking about making a claim to an employment tribunal, you should get help straight away from one of the organisations listed underFurther help.If you are being represented by a solicitor at the tribunal, they may ask you to sign an agreement where you pay their fee out of your compensation if you win the case. This is known as adamages-based agreement. In England and Wales, your solicitor cant charge you more than 35% of your compensation if you win the case.If you are thinking about signing up for a damages-based agreement, you should make sure youre clear about the terms of the agreement. It might be best to get advice from an experienced adviser, for example, at a Citizens Advice Bureau. To find your nearest CAB, including those that give advice by e-mail, click onnearest CAB.For more information about making a claim to an employment tribunal, seeEmployment tribunals.The (lack of) air up there Watch mCayman Islands-based Webb, the head of Fifas anti-racism taskforce, is in London for the Football Associations 150th anniversary celebrations and will attend Citys Premier League match at Chelsea on Sunday.I am going to be at the match tomorrow and I have asked to meet Yaya Toure, he told BBC Sport.For me its about how he felt and I would like to speak to him first to find out what his experience was.Uefa hasopened disciplinary proceedings against CSKAfor the racist behaviour of their fans duringCitys 2-1 win.Michel Platini, president of European footballs governing body, has also ordered an immediate investigation into the referees actions.CSKA said they were surprised and disappointed by Toures complaint. In a statement the Russian side added: We found no racist insults from fans of CSKA.Age has reached the end of the beginning of a word. May be guilty in his seems to passing a lot of different life became the appearance of the same day; May be back in the past, to oneself the paranoid weird belief disillusionment, these days, my mind has been very messy, in my mind constantly. Always feel oneself should go to do something, or write something. Twenty years of life trajectory deeply shallow, suddenly feel something, do it.一字开头的年龄已经到了尾声。或许是愧疚于自己似乎把转瞬即逝的很多个不同的日子过成了同一天的样子；或许是追溯过去，对自己那些近乎偏执的怪异信念的醒悟，这些天以来，思绪一直很凌乱，在脑海中不断纠缠。总觉得自己自己似乎应该去做点什么，或者写点什么。二十年的人生轨迹深深浅浅，突然就感觉到有些事情，非做不可了。The end of our life, and can meet many things really do?而穷尽我们的一生，又能遇到多少事情是真正地非做不可？During my childhood, think lucky money and new clothes are necessary for New Year, but as the advance of the age, will be more and more found that those things are optional; Junior high school, thought to have a crush on just means that the real growth, but over the past three years later, his writing of alumni in peace, suddenly found that isnt really grow up, it seems is not so important; Then in high school, think dont want to give vent to out your inner voice can be in the high school children of the feelings in a period, but was eventually infarction when graduation party in the throat, later again stood on the pitch he has sweat profusely, looked at his thrown a basketball hoops, suddenly found himself has already cant remember his appearance.童年时，觉得压岁钱和新衣服是过年必备，但是随着年龄的推进，会越来越发现，那些东西根本就可有可无；初中时，以为要有一场暗恋才意味着真正的成长，但三年过去后，自己心平气和的写同学录的时候，突然就发现是不是真正的成长了，好像并没有那么重要了；然后到了高中，觉得非要吐露出自己的心声才能为高中生涯里的懵懂情愫划上一个句点，但毕业晚会的时候最终还是被梗塞在了咽喉，后来再次站在他曾经挥汗如雨的球场，看着他投过篮球的球框时，突然间发现自己已经想不起他的容颜。Originally, this world, can produce a chemical reaction to an event, in addition to resolutely, have to do, and time.原来，这个世界上，对某个事件能产生化学反应的，除了非做不可的坚决，还有，时间。A persons time, your ideas are always special to clear. Want, want, line is clear, as if nothing could shake his. Also once seemed to be determined to do something, but more often is he backed out at last. Dislike his cowardice, finally found that there are a lot of love, there are a lot of miss, like shadow really have been doomed. Those who do, just green years oneself give oneself an arm injection, or is a self-righteous spiritual.一个人的时候，自己的想法总是特别地清晰。想要的，不想要的，界限明确，好像没有什么可以撼动自己。也曾经好像已经下定了决心去做某件事，但更多的时候是最后又打起了退堂鼓。嫌恶过自己的怯懦，最终却发现有很多缘分，有很多错过，好像冥冥之中真的已经注定。那些曾经所谓的非做不可，只是青葱年华里自己给自己注射的一支强心剂，或者说，是自以为是的精神寄托罢了。At the moment, the sky is dark, the air is fresh factor after just rained. Suddenly thought of blue plaid shirt; Those were broken into various shapes of stationery; From the corner at the beginning of deep friendship; Have declared the end of the encounter that havent start planning. Those years, those days of do, finally, like youth, will end in our life.此刻，天空是阴暗的，空气里有着刚下过雨之后的清新因子。突然想到那件蓝格子衬衫；那些被折成各种各样形状的信纸；那段从街角深巷伊始的友谊；还有那场还没有开始就宣告了终结的邂逅计划那些年那些天的非做不可，终于和青春一样，都将在我们的人生中谢幕。Baumgartner the disappointing news: Mission aborted. r plays an important role in this mission. Starting at the ground, conditions have to be very calm - winds less than 2 mph, with no precipitation or humidity and limited cloud cover. The balloon, with capsule attached, will move through the lower level of the atmosphere (the troposphere) where our day-to-day weather lives. It will climb higher than the tip of Mount Everest (5.5 miles/8.85 kilometers), drifting even higher than the cruising altitude of commercial airliners (5.6 miles/9.17 kilometers) and into the stratosphere. As he crosses the boundary layer (called the tropopause),e can expect a lot of turbulence.The supersonic descent could happen as early as S