【正文】 ventdata, handles)下添加程序見附錄1。 實(shí)驗(yàn)題目該界面選取兩個(gè)實(shí)驗(yàn)，即級(jí)聯(lián)型濾波器和格型濾波器實(shí)驗(yàn)。雙擊第二個(gè)按鈕，將String改為“實(shí)驗(yàn)結(jié)果”， Frontsize設(shè)為12。format ratnum=[3,5/3,2/3]。run text8,即返回到上一級(jí)text8界面，關(guān)閉的程序是closetext8,即退出這一級(jí)界面。在此界面上，可以輸入一系列參數(shù)，如幅度、角度、相位、平移量等參數(shù)。點(diǎn)擊各個(gè)信號(hào)控件時(shí)。 序列的基本運(yùn)算本實(shí)驗(yàn)的目的是加深對(duì)常用序列的理解，并進(jìn)行運(yùn)算和掌握MATLAB中一些基本函數(shù)的建立方法。當(dāng)輸入?yún)?shù)時(shí)，結(jié)果一目了然，也能結(jié)合實(shí)驗(yàn)內(nèi)容進(jìn)行相應(yīng)的學(xué)習(xí)。點(diǎn)擊“第三章 離散傅里葉變換”。方波傅里葉分析和離散傅里葉變換的程序見（附錄2）。當(dāng)參數(shù)不符合結(jié)果時(shí)，會(huì)出現(xiàn)錯(cuò)誤警告信息框。 卷積運(yùn)算 當(dāng)輸入卷積幅度時(shí)。截止頻率可以輸入?！巴顺觥笨丶梢苑祷刂鹘缑?。 警告信息、出現(xiàn)警告框。級(jí)聯(lián)型最大的特點(diǎn)是可以分別控制每個(gè)子系統(tǒng)的零點(diǎn)，因而當(dāng)需要精確控制數(shù)字濾波器的零點(diǎn)時(shí)，往往采用這個(gè)結(jié)構(gòu)。 實(shí)驗(yàn)內(nèi)容本實(shí)驗(yàn)要求實(shí)現(xiàn)系統(tǒng)的格型結(jié)構(gòu)。 實(shí)驗(yàn)內(nèi)容 本實(shí)驗(yàn)要求設(shè)計(jì)出多帶的FIR濾波器，并與期望的幅頻響應(yīng)的結(jié)果進(jìn)行比較。點(diǎn)擊“實(shí)驗(yàn)內(nèi)容”控件。點(diǎn)擊“實(shí)驗(yàn)結(jié)果”控件。（2）資料查找：本次設(shè)計(jì)需要找數(shù)字信號(hào)處理的實(shí)驗(yàn)和MATLAB的使用步驟，特別是界面設(shè)計(jì)的知識(shí)。大多數(shù)實(shí)驗(yàn)都是驗(yàn)證性實(shí)驗(yàn)，GUI界面操作起來(lái)有點(diǎn)煩雜，還需要改進(jìn)。本文將MATLAB作為二次開發(fā)平臺(tái)，結(jié)合理論教學(xué)的的內(nèi)容，利用圖形用戶界面的形式，開發(fā)該課程的教學(xué)實(shí)驗(yàn)系統(tǒng)，并對(duì)實(shí)驗(yàn)內(nèi)容所包括的主要功能進(jìn)行了詳細(xì)的說(shuō)明。其次要感謝的是同一組導(dǎo)師的各位同學(xué)，每個(gè)人對(duì)我的設(shè)計(jì)都有或多或少的啟發(fā)和幫助，他們教會(huì)我怎樣使用MATLAB的界面設(shè)計(jì)，使我的設(shè)計(jì)有了突破性的進(jìn)展。then we have where Q stands for quantization. Because of there nonlinear phenomena, analytical study of digital signals is plicated. There are, however no such problems in studying discretetime signals. In actual processing or implementation, all discretetime signals must be converted into digital signals. In quantization, if the amplitude of discretetime signal does not fall exactly on a quantization level, then the value must be approximated by a quantization level either by truncation or rounding, in either case, errors will occur. Such errors are called quantization errors.In general, quantization errors are studied separately in digital signal processing. Such a study is important in specialized hardware that uses a small number of bits such as 4 or 8 bits. On digital puters and DSP processors that have 16 or 32 bits, quantization errors are very small and can often be simply ignored. For convenience, we use digital signals and discretetime signals interchangeably with the understanding that all DT signals must be transformed into digital signals in implementation and al digital signals are considered an DT signals in analysis and design.Comparison of Digital and Analog TechniquesDigital techniques have bee increasingly popular and have replaces, in many applications, analog techniques. We discuss some of the reasons in the following.Digital techniques are less susceptible to noise and disturbance. In the transmission and processing of analog signals, any noise or disturbance will affect the signals. Digital signals are coded in 1s and 0s, which are represented by ranges of voltages。 sonar, where national security was at risk；irreplaceable。不過(guò)，由于這種表示法容易受噪聲、電源起伏及其他干擾的影響而未被采用。在此情況下，可以發(fā)送錯(cuò)誤信息，重傳信號(hào)。這種類型的表示受噪聲的影響較少,而且很容易實(shí)現(xiàn)?？紤]以下序列，　　 符號(hào)位 每一稱為一個(gè)二進(jìn)制位或比特，取值只能是1或0。在實(shí)際常見的信號(hào)大多是連續(xù)時(shí)間信號(hào)，要以數(shù)字化方式處理模擬信號(hào),應(yīng)先對(duì)模擬信號(hào)在時(shí)間上離散化以產(chǎn)生離散時(shí)間信號(hào)，然后對(duì)其幅值量化以產(chǎn)生數(shù)字信號(hào)。假設(shè)每個(gè)數(shù)值都四舍五入為最近的整數(shù)(即量化階為1)，則有　　這里Q表量化。量化時(shí),如果離散信號(hào)的幅度與量化電平不一致,那么就必須采用截?cái)嗷蛩纳嵛迦氲姆绞綄⑺炕癁槟硞€(gè)量化電平,在這兩種情況下,都會(huì)出現(xiàn)誤差，這種誤差被稱為量化誤差。由于在電路實(shí)現(xiàn)時(shí)必須將數(shù)字信號(hào)看作離散時(shí)間信號(hào),為方便起見，我們。但是，在采用很少的位數(shù)，比如4位或者8位的專用硬件中，量化誤差的研究是很重要的。然而,離散時(shí)間信號(hào)的研究就沒(méi)有這個(gè)問(wèn)題。然而，對(duì)于數(shù)字信號(hào)的分析研究是很困難的,因?yàn)榱炕皇蔷€性過(guò)程。例如,我們有　　1 1 0 0 1 1 ←→(1+0+0+1*+1*)=　　0 0 1 1 1 0←→0*+1*+1*+1*+0*=除符號(hào)位外最左邊的位是最高有限位,而最右邊的位是最低有效位。二進(jìn)制數(shù)編碼的方式有很多種。凹痕的前端和后端代表1。每個(gè)符號(hào)表示的精確電壓值并不重要,關(guān)鍵是它的值是否在上述任意一個(gè)允許的范圍內(nèi)。這些消息由26個(gè)英文字母組成，10個(gè)數(shù)字，逗號(hào)，句號(hào)等符號(hào)組成。 they can always be exactly reproduced.The storage of digital signals is easier than that of analog signals. Digital signals can be easily stored in shift registers, memory chips, floppy disks, or pact discs for an long an needed without loss of accuracy. These data can be retrieved for use in a few microseconds. This easy storage and rapid access is an important feature of digital techniques, the only convenient way to store analog signals is to tape or film them. Their retrieval is not an convenient and fast an in digital techniques.Digital techniques are more flexible and versatile than analog techniques. In digital display, digital signals can easily be frozen, expanded, or manipulated. A digital system can be easily ponents. Using time multiplexing, a digital syetem can be used to process a number of digital signals: for example, if the sampling period of a digital signal is and if the processing of the signal requires only , then the digital system will be free in the next and can be used to process other signals. Another example of this type of arrangement is the digital transmission of human voices. On a telephone line, the voice is sampled 8000 times per second。附錄1：外文文獻(xiàn)和翻譯外文原文 Introduction to Digital Signal ProcessingRepresentation of Digital SignalsMessages sent by telegraph are digital signals. They are written using 26 alphabetical characters, 10 numerals, are symbols such as mas and periods. These symbols certainly can be represented by different voltage levels, for example, A by 10V(volts), B by , C by 9V,and so forth. This type of representation , however, is not used because it is susceptible to noise, shifting of power supply, and any other disturbances. In practice, there symbols are coded sequences of dashes and dots or, equivalently, ones and zeros. The symbol 0 can be represented by a voltage from 0 to . the symbol 1 can be represented by voltage from to . The precise voltage of each symbol is not important, but it is critical that its value lies within one of the two allowable ranges. If the value lies outside the two allowable ranges, the telegraph must make a choice of either 1 or 0, On the pact disc, 1 and 0 are represented by dimples. The leading and trailing edges of dimple represent a 1。 參考文獻(xiàn)[1] 陳后金、薛鍵、胡健.《數(shù)字信號(hào)處理》，高等教育出版社，2004 [2] 薛年喜.《MATLAB在數(shù)字信號(hào)處理中的應(yīng)用》，清華大學(xué)出版社，2008[3] 沈捷、實(shí)驗(yàn)技術(shù)與管理，2008（2），25卷第2期[4]沈捷、電腦開發(fā)與應(yīng)用，2009,20卷第九期[5]陳亮、郝衛(wèi)東、喬建華，基于MATLAB的濾波器分析界面設(shè)計(jì)，現(xiàn)代電子技術(shù)，2009，第10期[6]劉舒帆、陸輝、費(fèi)諾，信號(hào)處理類實(shí)驗(yàn)課的階梯式教學(xué)研究，電子高等教育學(xué)會(huì)2005年學(xué)術(shù)年會(huì)論文集，2005[7]吳永深，基于VB與MATLAB的數(shù)學(xué)與數(shù)字信號(hào)處理實(shí)驗(yàn)系統(tǒng)的設(shè)計(jì)與實(shí)現(xiàn)，東莞理工學(xué)院學(xué)報(bào)，2006，第13卷第3期[8]肖江、張鴻存、費(fèi)諾、劉舒帆，數(shù)字信號(hào)處理實(shí)驗(yàn)系統(tǒng)的結(jié)果與應(yīng)用，實(shí)驗(yàn)室研究與探索，2001，第20卷第4期[9]李顯宏，《》，電子工業(yè)出版社，2006