测试信号课件no chapter

1、Measurement Signal Analysis and Processing （Digital Signal Processing）Dr. Hong ZengSchool of Instrument Science and EngineeringSoutheast UniversityWho, When and Where Instructor Dr. Hong Zeng (曾曾 洪洪) （M.E. SEU, Ph.D HKBU） Email: Prof. Ruqiang Yan (严如强严如强) (M.E. USTC, Ph. D UMass) Classes: Monday 8:0

2、0-10:00, Rm106, 2nd Teaching building (Odd weeks) Wednesday 10:00-12:00, Rm106, 2nd Teaching building (Odd and even weeks)2Textbook3Grading Policy Homework - 10% Assignments to be completed on time, No late homework will be accepted DO NOT copy others homework, otherwise, zero grades will be assigne

3、d Final Exam 90% Attendance record 5 points per absence4Teaching and Learning Bilingual Teaching Basic terms, theories, Generally in English Difficulties, some examples will be illustrated in Chinese! Assignments and Exams in English In-class discussions & quizzes in either English or Chinese Ta

4、king notes, reviewing lecture notes & book5Chapter 1 Introduction to Digital Signal Processing6Agenda Signals and Typical Operations Overview of Digital Signal Processing Why Go Digital? Topics of this Course Typical DSP Applications7Signals Signals A signal can be defined as a function that con

5、veys information. Signals are presented mathematically as functions of one or more independent variables.8Classification of Signals One-dimensional (1-D) signal v. s. multi-dimensional signals Scalar signals vs. vector (multi-channel) signals Continuous signals vs. discrete signals9One-dimensional (

6、1-D) signal v. s. multidimensional signals10Typical 1-D Signals Speech and music signals - Represent air pressure as a function of time at a point in space, i.e., f(t) Waveform of the speech signal “I like digital signal processing” is shown below11voltage Signals in Telecommunication (generally, in

7、 voltage)12Baseband signalRadio frequency signal Vibration signals in Mechanical systemsThe vibration of a mechanical system is sensed by the sensor attached with the Mechanical systems, which is then converted into an electrical signal shown above. 13 Electrocardiography (ECG) Signal - Represents t

8、he electrical activity of the heart A typical ECG signal is shown belown The ECG trace is a periodic (周期性的) waveformn One period of the waveform shown on the left represents one cycle of the blood transfer process from the heart to the arteries14Typical 2-D Signals Black-and-white picture - represen

9、ts light intensity as a function of two spatial coordinates - Two-dimensional (2-D) signal 二维信号15Typical 3-D Signals Video signals - Consists of a sequence of images, called frames, and is a function of 3 variables: 2 spatial coordinates (x,y) and time (t)Click to play the video16Scalar signals vs.

10、vector (multi-channel) signals17Typical multichannel signals Electroencephalogram (EEG) Signals -Represent the electrical activity caused by the random firings of billions of neurons in the brain18清华大学利用想象运动机制控制机器狗踢球EEG singnal Each waveform is still a function of only one variable (i.e., time) Wave

11、s are sensed by multiple sources or areas at the same time (i.e. EEG is a multichannel signal)1( )2( )( )( )channel tchanneltEEG tchannelN t1920 The full color image obtained by displaying the previous 3 color components is shown below( , )I( , )( , )( , )R x yx yG x yB x y21channelchannelchannel?U(

12、 , , )?x y t 22Continuous signals vs. discrete signals23自变量连续，幅度连续24(量化阶梯信号量化阶梯信号)自变量连续，幅度离散25自变量离散，幅度连续26自变量离散，幅度离散4 types of signals27Typical Signal Processing Operations Simple Time-Domain Operations Scaling: , is a constant Delay: Addition: Integration: Differentiation: Product: Filtering Convol

13、ution integral: 282930Overview of Digital Signal Processing This course is concerned with the discrete- time representation of signals and their discrete-time processing or analyzingWe will perform numerical operations including, for example, additions, multiplications, data transfersand logical ope

14、rations, either using computer or special-purpose hardware (DSP chips or processors)(01011.)(11101.)31General DSP Scheme Scheme for the digital processing of an analog signal(a)(b)(c)(d)(e)(f)32 The Equivalent Analog Signal ProcessorAnalog Signal ProcessorAnalog InputAnalog OutputReal analog circuit

15、s process the signal using -resistors (电阻)-capacitors （电容）-inductors （电感）-amplifiers （放大器）- R C x(t) y(t) Continuous-time low pass filter33Why Go Digital?3435 The impossible with analog implementation- linear phase, multi-rate processing, 36制作- Digital system can be simply reprogrammed for other app

16、lications / ported to different hardware / duplicated(Reconfiguring analog system means hadware redesign, testing, verification)37(LSI, VLSI). 38Limitations of DSP Lesser Reliability Digital systems are active devices, and thus use more power and are less reliable Limited range of frequencies availa

17、ble for processing （bottleneck :speed of ADC/DAC, DSP）39 Additional Complexity in the Processing of Analog Signals A/D and D/A converters must be introduced adding complexity to overall system40Topics of this Course1 Introduction to Signals and Signal Processing 2 Discrete-Time Signals and Systems i

18、n the Time Domain 3 Discrete-Time Signals in the Transformed Domain 4 Discrete-Time Systems in the Transform Domain5 Digital Processing of Continuous-Time Signals 6 Digital Filter Structures 7 Digital Filter Design 41DSP Application Examples (aims)Signal processing To improve the quality of a signal

19、ExamplesSignal Filtering (Noise, Interference , Echo cancellation)Signal coding and compressionSignal analyzing To extract useful information carried by signalsExamplesSpectrum analysis (频谱分析)Feature extraction （特征提取）Target detection, verification, recognition42测试信号分析与处理技术 测试信号分析与处理技术在测试领域的主要测试信号分析与

20、处理技术在测试领域的主要功能主要有：功能主要有： 信号的谱分析信号的谱分析 信号的滤波信号的滤波 信号的特征抽取信号的特征抽取 4344Example DSP Applications (areas)n MILITARYnSecure CommunicationsnSonar ProcessingnImage ProcessingnRadar ProcessingnNavigation, Guidancen VOICE/SPEECHnSpeech RecognitionnSpeech Processing/VocodingnSpeech EnhancementnText-to-SpeechnV

21、oice Mailn INSTRUMENTATIONnSpectrum AnalyzersnSeismic ProcessorsnDigital OscilloscopesnMass Spectrometersn MEDICALnPatient MonitoringnUltrasound EquipmentnDiagnostic ToolsnFetal MonitorsnLife Support SystemsnImage Enhancementn INDUSTRIAL/CONTROLnRoboticsnNumeric ControlnPower Line MonitorsnMotor/Servo Controln CONSUMERnRadar DetectorsnPower ToolsnDigital Audio / TVnMusic SynthesizersnToys / GamesnAnswering MachinesnDigital Speakersn PRO-AUDIOnAV EditingnDigital MixersnHome TheaternPro Audion COMMUNICATIONSnEcho CancellationnDigital PBXsnLine RepeatersnMod