数字信号处理原理.ppt
数字信号处理基础,安 冬,第一章 数字信号处理概述,FIGURE 1-1 Applications of DSP.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,Touch-Tone telephonesEdge detection in imagesDigital signal and image filteringSeismic analysisText recognitionSpeech recognitionMagnetic resonance image(MRI)scansMusic synthesisBar code readersSonar processingSatellite image analysisDigital mappingCellular telephonesDigital camerasDetection of narcotics and explosives,Speech synthesisEcho cancellationCochlear implantsAntilock brakesSignal and image compressionNoise reductionCompandingHigh definition television(HDTV)Digital audioEncryptionMotor controlRemote medical monitoringSmart appliancesHome securityHigh speed modems,FIGURE 1-2 Examples of signals.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-2 Examples of signals.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-2 Examples of signals.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-2 Examples of signals.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-2 Examples of signals.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,Courtesy Michael Noonan,Ph.D.Canisus College,FIGURE 1-2 Examples of signals.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-3 Black and white image.Snap-.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-4 Four frames from high-speed video sequence.“Vision Research,Inc.,Wayne,NJ.,USA.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-4 Four frames from high-speed video sequence.“Vision Research,Inc.,Wayne,NJ.,USA.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-4 Four frames from high-speed video sequence.“Vision Research,Inc.,Wayne,NJ.,USA.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-4 Four frames from high-speed video sequence.“Vision Research,Inc.,Wayne,NJ.,USA.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-11 A/D and D/A conversion.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,数字信号处理的理论部分：指人们为了得到满足需要的信号形式而对数字化的信号进行处理的数学原理、方法和手段。信号处理的内容包括：变换、滤波、检测、谱分析、估计、压缩、识别等。数字信号处理以1965年 Cooley-Turkey在计算数学上发表的“用机器计算复序列傅里叶级数的一种算法”“FFT”为标志开始形成并发展的。在40年的时间里，数字信号处理的理论和技术日趋成熟与完善，用数字方法来处理信号，已逐渐取代模拟信号处理。数字信号处理已广泛应用于各工程技术领域，包括语音、图像、通讯、控制、航天、医疗、生医、地质勘探、建筑等。,数字信号处理器（Digital Signal Processor,DSPs）,是指一类具有专门为完成数字信号处理任务而优化设计的系统体系结构、硬件和软件资源的单片可编程处理器件。数字信号处理器是实现数字信号处理任务的一个重要而有效的手段。,特别是随着通信和信息技术的飞速发展，数字信号处理器件得到了空前的发展和应用。现在，掌握和熟练应用数字信号处理器件已经成为相关行业高级技术人才的一项重要技能。,世界上第一颗DSP芯片诞生于1978年,AMI公司发布的 S2811。目前，世界上主要的半导体厂商基本都有基于DSP的产品发布，包括TI公司、AD公司、Motorola公司、Lucent等。DSP市场是半导体市场增长最快的亮点，凭借其无与伦比的信息处理能力，数字处理器以比最快的PC微处理器还快10-50倍的处理速度无可厚非地代替着MPU的位置，成为数字化电子世界中越来越处于主导地位的电脑芯片。,DSP是围绕着数字信号处理的理论、实现和应用等几个方面发展起来的。数字信号处理在理论上的发展推动了数字信号处理应用的发展。反过来，数字信号处理的应用又促进了数字信号处理理论的提高。而数字信号处理的实现则是理论和应用之间的桥梁。1）理论：,1、数字信号处理的基本内容,信号理论,信号分析：用解析的方法表示信号，信号与系统,信号传输：用最经济有效的方法来传输最大的信息量，通 信原理,信号处理：基本任务,信息的采集与获取：模 数信息的重排：抽取、内插信息的压缩：图像编码压缩,滤波、变换、压缩、估计、重排等,2）实现方法(1)在通用的计算机上用软件(如Fortran、C语言、Matlab语言)实现；速度较慢，一般可用于DSP算法的模拟(2)在通用计算机系统中加上专用的加速处理机实现；专用性强，应用受到很大的限制(3)用通用的单片机（如MCS-51、96系列等）实现，这种方法可用于一些不太复杂的数字信号处理，如数字控制等；只适用于实现简单的DSP算法(4)用通用的可编程DSP芯片实现。与单片机相比，DSP芯片具有更加适合于数字信号处理的软件和硬件资源，可用于复杂的数字信号处理算法；(5)用专用的DSP芯片实现。在一些特殊的场合，要求的信号处理速度极高，通用DSP芯片很难实现，如专用于FFT、数字滤波、卷积相关等算法的DSP芯片，这种芯片将相应的信号处理算法在芯片内部用硬件实现，无需进行编程。专用性强，应用受到很大的限制,只有第4种方法才使数字信号处理的应用打开了新的局面。虽然数字信号处理的理论发展迅速，但在20世纪80年代以前，由于实现方法的限制，数字信号处理的理论还得不到广泛的应用。直到20世纪70年代末80年代初世界上第一片单片可编程DSP芯片的诞生，才将理论研究结果广泛应用到低成本的实际系统中，并且推动了新的理论和应用领域的发展。可以毫不夸张地说，DSP芯片的诞生及发展对近几十年来通信、计算机、控制等领域的技术发展起到十分重要的作用。,FIGURE 1-5 Analog voltage signal.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-6 Sample-and-hold signal.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-7 Quantization and digitization.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-8 Digital signal.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-9 Zero order hold signal.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-10 Recovered analog signal after smoothing.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-13 Signals and spectra.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-13 Signals and spectra.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-14 A single piano note(middle C)and its time trace.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-15 Spectrum of middle C(200-500 Hz).,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-16 A piano chord(CEG)and its time trace.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-17 Spectrum of CEG chord(200-500 Hz).,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-18 Examples of spectra.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-18 Continued.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-18 Continued.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-18 Continued.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-18 Continued.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-18 Continued.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-19 Bass,tenor,alto,and soprano singing ranges.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-20 Low pass filter to extract bass voices.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-21 High pass filter to extract soprano voices.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-22 Band pass filter to extract alto voices.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-23 Spectrum for CEG chord(250-2500 Hz).,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-24 Low pass filtering a piano chord,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 1-24 Continued.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,第二章 模数转换和数模转换,FIGURE 2-1 Typical digital signal processing system.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,SAMPLING,The sampling interval,or sampling period is the time in seconds between sampling points.The sampling frequency,or sampling rate,is the number of samples per second,measured in HertzRelation:,FIGURE 2-2 Analog signal.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 2-3 Sample-and-hold signal(shown with analog signal).,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 2-4 Digital signal(shown with sample-and-hold signal).,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 2-5 Undersampled analog signals.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,Nyquist Sampling theorem,A signal with maximum frequency of W Hz must be sampled at least 2W times per seconds to make it possible to reconstruct the original signal being sampled.This minimum sampling frequency is called the Nyquist sampling rate.,FIGURE 2-6 Aliasing in the time domain with 40 kHz sampling(adapted from Pohlmann,1994).,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 2-7 Antialiasing Filter.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 2-7 Antialiasing Filter.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 2-7 Antialiasing Filter.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,Quantization step,N is the number of bitsR is the full scale analog rangeThe quantization step size is sometimes referred to as the resolution of the quantizer.Quantization error=Quantization value-Actual value,FIGURE 2-15 Quantization of unipolar data(maximum error=full step).,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 2-16 Quantization of unipolar data(maximum error=half step).,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 2-18 Quantization of bipolar data(maximum error=half step).,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 2-19 Analog-to-digital conversion.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 2-20 A/D.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 2-21 Three-bit A/D conversion.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 2-22 Serial digital bitstream.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 2-23 Digital-to-analog conversion.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,DIGITAL-TO-ANALOG CONVERSION,FIGURE 2-24 D/A.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 2-25 Three-Bit D/A conversion.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 2-26 Comparing signals in the A/D/D/A chain.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 2-26 Comparing signals in the A/D/D/A chain.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All rights reserved.,FIGURE 2-26 Comparing signals in the A/D/D/A chain.,Joyce Van de VegteFundamentals of Digital Signal Processing,Copyright 2002 by Pearson Education,Inc.Upper Saddle River,New Jersey 07458All
