毕业论文-基于Matlab的数字通信系统调制解调研究11503.doc

滨州学院本科毕业设计（论文） i 毕 业 设 计 （ 论 文 ） 题 目 基于 matlab 的数字通信系统调 制解调研究 系 （院） 计算机科学技术系 专 业 通信工程 班 级 2008 级 2 班 学生姓名 李发 学 号 2008110310 指导教师 谭雪霏 职 称 讲师 二一二年五月二十日 滨州学院本科毕业设计（论文） ii 基于 matlab 的数字通信系统调制解调研究 摘 要 当今，随着通信技术日新月异的发展，尤其是数字通信的快速普 及，使得通信技术日新月异。现代通信系统要求通信距离远、通信容 量大、传输质量好，因此通信系统也日趋复杂。在各种通信系统的设 计研发环节中，软件仿真已成为必不可少的部分。应用 matlabsimulink 的计算机仿真具有经济、安全、可靠、编程简易以及 实验周期短等特点。 因此，本文就以 matlab 为软件平台，利用其通信工具箱和信号处 理工具箱中的模块，尤其是 matlab 语言的 simulink 动态系统仿真软件 包，对数字调制解调系统进行仿真，并且对仿真结果进行误差分析， 从而对现代数字通信有更加明确的认识和直观的了解。重点对 2ask、2psk 、2fsk 进行性能比较，在实际通信系统中，根据具体情 况选择最合适的调制方式，进一步促进数字通信的发展。 本 文 首 先 介 绍 了 课 题 研 究 的 背 景 和 进 行 数 字 通 信 仿 真 的 意 义 ， 然 后 介 绍 对 数 字 通 信 系 统 进 行 仿 真 所 使 用 的 matlab simulink 软 件 以 及 这 些 软 件 在 使 用 时 的 注 意 事 项 和 采 用 的 一 些 方 法 ， 随 后 又 介 绍 了 数 字 调 制 系 统 的 原 理 并 据 此 进 行 数 字 调 制 解 调 系 统 的 仿 真 ， 最 后 对 仿 真 结 果 进 行 误 差 分 析 ， 对 设 计 进 行 总 结 归 纳 。 关 键 词 ： 数 字 通 信 系 统 ； 调 制 解 调 ； matlab； simulink； 仿 真 滨州学院本科毕业设计（论文） iii research of modulation and demodulation in digital communication system based on the matlab abstract nowadays, with the rapid development of communication technology, especially the rapid spread of the digital communication, makes communication technology is developing rapidly. modern communication system requirements communication distance, communication capacity, transmission quality is good, because this communication system has become more and more complex. in all kinds of communication system design r 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 滨州学院本科毕业设计（论文） 38 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. we often close ourselves off when traumatic events happen in our lives; instead of letting the world soften us, we let it drive us deeper into ourselves. we try to deflect the hurt and pain by 滨州学院本科毕业设计（论文） 39 pretending it doesnt exist, but although we can try this all we want, in the end, we cant hide from ourselves. we need to learn to open our hearts to the potentials of life and let the world soften us. 生活发生不幸时，我们常常会关上心门；世界不仅没能慰藉我们，反倒使我们更加消沉。 我们假装一切仿佛都不曾发生，以此试图忘却伤痛，可就算隐藏得再好，最终也还是骗不 了自己。既然如此，何不尝试打开心门，拥抱生活中的各种可能，让世界感化我们呢？ whenever we start to let our fears and seriousness get the best of us, we should take a step back and re-evaluate our behavior. the items listed below are six ways you can open your heart more fully and completely. 当恐惧与焦虑来袭时，我们应该退后一步，重新反思自己的言行。下面六个方法有助于你 更完满透彻地敞开心扉。whenever a painful situation arises in your life, try to embrace it instead of running away or trying to mask the hurt. when the sadness strikes, take a deep breath and lean into it. when we run away from sadness thats unfolding in our lives, it gets stronger and more real. we take an emotion thats fleeting and make it a solid event, instead of something that passes through us. 当生活中出现痛苦的事情时，别再逃跑或隐藏痛苦，试着拥抱它吧；当悲伤来袭时，试着 深呼吸，然后直面它。如果我们一味逃避生活中的悲伤，悲伤只会变得更强烈更真实 悲伤原本只是稍纵即逝的情绪，我们却固执地耿耿于怀 by utilizing our breath we soften our experiences. if we dam them up, our lives will stagnate, but when we keep them flowing, we allow more newness and greater experiences to blossom.深呼吸能减缓我们 的感受。屏住呼吸，生活停滞；呼出呼吸，更多新奇与经历又将拉开序幕。2. embrace the uncomfortable we all know what that twinge of anxiety feels like. we know how fear feels in our bodies: the tension in our necks, the tightness in our stomachs, etc. we can practice leaning into these feelings of discomfort and let them show us where we need to go.我们都经历过焦灼的煎熬感，也都感受过恐惧造成的生理反应：脖子僵硬、胃酸翻腾。 其实，我们有能力面对这些痛苦的感受，从中领悟到出路。 the initial impulse is to run away to try and suppress these feelings by not acknowledging them. when we do this, we close ourselves off to the parts of our lives that we need to experience most. the next time you have this feeling of being truly uncomfortable, do yourself a favor and lean into the feeling. act in spite of the fear. 我们的第一反应总是逃避 以为否认不安情绪的存在就能万事大吉，可这也恰好妨碍了 我们经历最需要的生活体验。下次感到不安时，不管有多害怕，也请试着勇敢面对吧。 3. ask your heart what it wants 倾听内心 were often confused at the next step to take, making pros and cons lists until our eyes bleed and our brains are sore. instead of always taking this approach, what if we engaged a new part of ourselves that isnt usually involved in the decision making process?我们常对未来犹疑不定，反复考虑利弊直到身心 俱疲。与其一味顾虑重重，不如从局外人的角度看待决策之事。from: /englisharticle/yingyumeiwen/2013-08-06/227968.html the supersonic descent could happen as early as sunda. the weathethe balloon will slowly drift to the edge of space at 120,000 feet (then, i would assume, he will slowly step out onto something resembling an olympic diving platform. 滨州学院本科毕业设计（论文） 40 below, the earth becomes the concrete bottom of a swimming pool that he wants to land on, but not too hard. still, hell be traveling fast, so despite the distance, it will not be like diving into the deep end of a pool. it will be like he is diving into the shallow end. skydiver preps for the big jump when he jumps, he is expected to reach the speed