数字信号处理课程设计任务书-.doc

数字信号处理课程设计指导一、课程设计目的：综合运用本课程的理论知识进行频谱分析以及滤波器设计，通过理论推导得出相应结论，并利用MATLAB作为工具进行实现，从而复习巩固课堂所学的理论知识，提高对所学知识的综合应用能力，并从实践上初步实现对数字信号的处理。二、课程设计任务：每位同学在“四、课程设计内容”中的题目中任选一题或自行选择题目，每个题目最多4个人选。自行选择的题目需经过指导老师确认。班长于第五天把统计好的题目提交给指导老师。三、课程设计时间安排：第一天：布置设计任务，讲解设计要求，提示设计要点。第二五天：选定题目，查阅资料（在图书馆或上网），弄清题目要求，提出解决方案。)第五十二天：根据题目要求，将理论推导与编程实现相结合，写出设计报告和ppt，可以申请去实验室进行课程设计，也可以自己安排。第十三至十五天：答辩。四、课程设计内容：1. 设计题目一：编程实现任意确定信号的频谱分析算法(1) 对给定的CEG和弦音音频文件取合适长度的采样记录点，然后进行频谱分析（信号的时域及幅频特性曲线要画出）。(2) 分析CEG和弦音频谱特点，对该信号频谱能量相对较为集中的频带（分低、中、高频）实现滤波（分别使用低通，带通及高通），显示滤波后信号的时域和频域曲线，并对滤波后的信号与原信号的音频进行声音回放比较。(3) 在低、中、高三个频带中，各滤出三个能量最集中的频簇，显示滤波后信号的时域和频域曲线。(4) 任意选择几个滤出的频带（或频簇）进行时域信号重建（合成），与原信号的音频进行声音回放比较。讨论：根据上述结果，分析什么是和弦音。2. 设计题目二：设计并实现FIR数字滤波器的窗函数设计算法要求：输入数字滤波器指标，包括滤波器类型（低通、带通、带阻或高通等），通带截止频率，通带最大波动，阻带开始频率，阻带衰减， 设计得到FIR滤波器，并画出设计得到的滤波器的增益曲线图（要有坐标标度）。为了使编制的程序操作方便，设计处理系统的用户界面：在所设计的系统界面上 可以选择滤波器的类型，输入滤波器的参数，显示滤波器的频率响应，选择输入信号并显示相应的输出信号等。讨论：对不同窗函数、不同阶数的设计结果的参数及性能进行比较。3. 设计题目三：语音信号的处理与滤波内容：录制一段个人自己的语音信号，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，采用 窗函数法和双线性变换法设计滤波器，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；换一个与你性别相异的人录制同样一段语音内容，分析两段内容相同的语音信号频谱之间有什么特点；再录制 一段同样长时间的背景噪声叠加到你的语音信号中，分析叠加前后信号频谱的变化，设计一个合适的滤波器，能够把该噪声滤除。 基本步骤：(1) 语音信号的采集熟悉并掌握MATLAB中有关声音（wave）录制、播放、存储和读取的函数，在MATLAB环境中，使用声音相关函数录制3秒左右自己的声音。(2) 语音信号的频谱分析要求首先画出语音信号的时域波形；然后对语音号进行快速傅里叶变换，得到信号的频谱特性，从而加深对频谱特性的理解。(3) 设计数字滤波器并画出其频率响应给出各滤波器的性能指标： (i)低通滤波器性能指标：fb1000 Hz，fc1200 Hz，As100dB，Ap1dB。 (ii)高通滤波器性能指标：fc4800 Hz，fb5000 Hz As100dB，Ap1dB。 (iii)带通滤波器性能指标：fp11200 Hz，fp23000 Hz，fsc11000 Hz，fsc23200Hz，As100dB，Ap1dB。要求用窗函数法和双线性变换法设计上面要求的3种滤波器。在Matlab中，使用函数butter，cheby1等函数设计IIR滤波器；利用Matlab中的函数freqz画出各滤波器的频率响应。(4) 用滤波器对信号进行滤波要求用自己设计的各种滤波器分别对采集的信号进行滤波，在Matlab中，FIR滤波器利用函数fftfilt对信号进行滤波，IIR滤波器利用函数filter对信号进行滤波。(5) 比较滤波前后语音信号的波形及频谱要求在一个窗口同时画出滤波前后的波形及频谱。(6) 回放语音信号在Matlab中，使用相关声音函数对声音进行回放。辨别滤波前后的声音有何变化。(7) 男女声语音信号频谱特点分析换一个与你性别相异的人录制同样一段语音内容，分析两段内容相同的 (8) 背景噪声滤除再录制一段同样长时间的背景噪声（频谱能量集中在某个小范围内）叠加到你的语音信号中，分析叠加前后信号频谱的变化，设计一个合适的滤波器，能够把该噪声滤除。4. 设计题目四：基3-FFT算法实现 设计N=3k点数据的基3-FFT算法，分析算法所需的加法和乘法次数，画出9点基3-FFT算法的信号流图，并标出相应的旋转因子。5. 设计题目五：用FFT实现快速卷积 FFT的出现，使DFT在数字通信、语音信号处理、图像处理、功率谱估计、系统分析与仿真、雷达信号处理、光学、地震及数值分析等各个领域都得到广泛应用。然而，各种应用一般都以卷积和相关运算为依据。在实际应用中，为了分析时域离散LTI系统或者序列滤波时，需要计算两个序列的线性卷积。为了提高运算速度，可以利用FFT来实现。查找资料，编写程序实现利用DFT实现线性卷积的两种方法：重叠保留法和重叠想加法。6. 设计题目六：揭示声波测距的秘密声波测距的原理很简单：声波发射器发出声波，接受器接收反射回波，计算中间的时延，乘以声波速度再除以2，就得到了距离。在这里要求用喇叭和麦克风来搭建一个最简单的声波测距系统。要求：（1）合成测距用的chirp信号；（2）将系统对准天花板播放chirp信号并采集回波；（3）用相关方法来识别回波信号位置；（4）根据回波位置折算距离。7. 设计题目七：钢琴琴键声音合成钢琴声音优美号称“乐器之王”，据研究发现钢琴的声音是若干基本频率的倍频合成的。笔者对此进行了分析试验，弹奏钢琴产生16个音符，分别是“Do/Re/Mi/Fa/So/La/Si/Do(高)/ Do(高)/Si/La/So/Fa/Mi/Re/Do”，对此信号进行STFT，时频谱如下图所示：试验很好的验证了上述理论。根据上述论述题目的基本要求如下：(1) 找到Do/Re/Mi/Fa/So/La/Si/Do(高)的基频；(2) 找出基频与倍频之间能量比率的关系；(3) 编写函数，用正弦波来合成钢琴的声音。8. 设计题目八：经典滤波器的设计和使用自行产生一个数字信号，要求：(1) 必须包含低频、中频、高频分量；(2) 画出数字信号的时域波形图和频谱图；(3) 对数字信号进行采样，并进行频谱分析；(4) 分别设计低通、带通、高通三种滤波器，画出三个滤波器的频率响应；(5) 对信号进行滤波处理，观察滤波后信号的频谱。9. 设计题目九：信号谱分析研究高密度谱与高分辨率频谱。对连续确定信号：以采样频率fs=32kHz对信号采样得离散信号，分析下列三种情况的幅频特性。(1) 采集数据长度取N=16点，编写程序计算出的16点DFT,并画出相应的幅频图(2) 采集数据长度N=16点，补零加长至M点(长度M自己选)，利用补零DFT计算 的频谱并画出相应的幅频图。 (3) 采集数据长度取为M点（注意不是补零至M），编写程序计算出M点采集数据的的频谱并画出相应的幅频图。 10.设计题目十：信号识别识别含噪正弦信号的频率和幅度。对于含噪正弦信号，我们可以建模为：。本项目要求对上述信号进行采样，然后通过信号处理方法识别出正弦信号的幅度和频率。四、课程设计要求：1设计说明书（约30004000字），包括：（1）封面；（2）目录；（3）摘要；（4）正文。设计内容（简述本设计的任务和要求，可参照任务书和指导书）；设计原理（简述设计过程中涉及到的基本理论知识）；设计过程（按设计步骤详细介绍设计过程，即任务书和指导书中指定的各项任务）I程序源代码：给出完整源程序清单；II调试分析过程描述：包括测试数据、测试输出结果，以及对程序调试过程中存在问题的思考（列出主要问题的出错现象、出错原因、解决方法及效果等）；III结果分析：对程序结果进行分析，并与理论分析进行比较。（5）结论：包括课程设计过程中的学习体会与收获、对Matlab语言和本次课程设计的认识以及自己的建议等内容； （6）参考文献。2附件：（可以将设计中得出的波形图和频谱图作为附件，在说明书中涉及相应图形时，注明相应图形在附件中位置即可；也可不要附件，所有内容全部包含在设计说明书中。所有的实验结果图形都必须有横纵坐标标注，必须有图序和图题。）3课程设计报告提交电子版和打印版各一份。About the class projectsThe class includes a programming project. Your choice of project should be agreed with me; the easiest way is probably via email. Some ideas are given at the bottom of this page, but they are only to get you thinking; your project can be on any topic that interests you, and I encourage you to choose something that will help harness your enthusiasm. The biggest benefit of doing a project is that it will expose you to a broader range of the activities that come up in real engineering applications of signal processing, instead of the narrow core weve mostly covered in class. For this reason, the core requirement is that you do some kind of processing of some kind of real signal - i.e., I dont want a purely theoretical discussion, and I dont want experiments on ideal signals. In some cases, its useful to work with synthetic signals (ones you have constructed yourself, rather than gathered from the real world), but they should be as real as possible, i.e., by adding random noise etc. I strongly recommend you do your project in Matlab because it frees you from many of the low-level details, but other languages or systems can be used by prior arrangement.Projects can be done individually, or by a small team (typically two students). I encourage you to consider teaming up, primarily because it will allow you to do a more interesting project. I will naturally be judging two-person projects differently from individual projects, but I wont be applying a tougher standard - just looking for a more extensive investigation. The best arrangement is to choose a division of the project so that each of you can work on separate but interlocking parts. Learning teamwork is also one of the goals of an engineering education, so team projects will pick up points for demonstrating a successful ability to work with others. The projects will be graded based on a project report (of around 5 pages) as well as an optional in-class presentation. If you do a presentation, I will accept the presentation slidepack as part of the report, although I would still want a few pages of narration to explain the slides and to cover the points below. I do encourage you to make in-class presentations - its particularly fun if you have demonstrations such as sound examples. However, we wont have time for everyone to make presentations, so please let me know as soon as possible.Your report must have the following structure, using these section headings: 1. Introduction: A general description of the area of your project and why youre doing it.2. Problem Specification: A clear and succinct technical description of the problem youre addressing. Formulating a general problem (e.g., transcribing music) into a well-defined technical goal (e.g., reporting a list of estimated fundamental periods at each time frame) is often the most important part of a project.3. Data: What are the real-world and/or synthetic signals you are going to use to develop and evaluate your work?4. Evaluation Criteria: How are you going to measure how well your project performs? The best criteria are objective, quantitative, and discriminatory. You want to be able to demonstrate and measure improvements in your system.5. Approach: A description of how you went about trying to solve the problem. Sometimes you can make a nice project by contrasting two or more different approaches.6. Results and Analysis: What happened when you evaluated your system using the data and criteria introduced above? What were the principal shorfalls? (This may require you to choose or synthesize data that will reveal these shortcomings.) Your analysis of what happened is one of the most important opportunities to display your command of signal processing concepts.7. Development: If possible, you will come up with ideas about how to improve the shortcomings identified in the previous section, and then implement and evaluate them. Did they, in fact, help? Were there unexpected side-effects?8. Conclusions: What did you learn from doing the project? What did you demonstrate about how to solve your problem?9. References: Complete list of sources you used in completing your project, with explanations of what you got from each.The reason for this somewhat arbitrary structure is simply to help you avoid some of the more problematic weaknesses Ive seen in past years. If youre having trouble fitting your work into these sections, you should probably think more carefully about your project. If you have a good reason for deviating from this structure, talk to me or the TA. The project reports are due one month before summer holiday, i.e., June 3rd. Electronic submission is encouraged, PDF format and Word .DOC files are acceptable.