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单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,2024/10/12,1,Signals and Systems,He Chun(SCIE,UESTC),;Room:KB244A,2024/10/12,2,Course Description,Lectures:68+4,Week 1-17,Mon.,（,5,6,）,:Room A-412,Wed.,（,3,4,）,:Room A-412,Fri.,（,3,4;even,）,:Room A-302,Experiment:4+4+16,Software Experiment:4,Hardware Experiment:4,Project based on software platform:16,2024/10/12,3,Course Description,2024/10/12,4,Grading,ACTIVITIES,PERCENTAGES,Middle Exam,20%,Final Exam,50%,Exercises,10%,Experiments,20%,2024/10/12,5,Textbook,Second Edition,Alan V.Oppenheim,Alan S.Willsky (M.I.T),S.Hamid Nawab (B.U.),Signals and Systems,1,Simon Haykin,，,Barry Van Veen,，,Signals&Systems,Second Edition,Publishing House of Electronics Industry,，,2003,2,郑君里，应启珩，杨为理，信号与系统,(,第二版,),，北京：高等教育出版社，,2000,年,3,闵大镒，朱学勇，信号与系统分析，电子科技大学出版社，,2000,年,4,吕幼新，张明友，信号与系统，电子工业出版社，,2003,年,References,Exploration in Signals and Systems Using MATLAB,John R.Buck,Michael M.Daniel,Signals and Systems,2024/10/12,6,2024/10/12,7,Foreword,What shall we study?,-The,concepts,、,theory,and techniques,of signals and systems,analysis,Why shall we study?,-Extraordinarily wide variety of,applications,How shall we study?,-Understand with,mathematical concept,physic concept and engineering concept,-Do exercises and activities,2024/10/12,8,Foreword,What is,Signal,?,A,function,of one or more,independent variables that contain information about the behavior or nature of some phenomenon.,We encounter many types of signals in various applications,Electrical signals:voltage,current,magnetic and electric fields,Mechanical signals:velocity,force,displacement,Acoustic signals:sound,vibration,Other signals:pressure,temperature,2024/10/12,9,Respond to particular signals by producing other signals or some desired behaviors.,e.g.,Filters,，,Parameter estimation.,Foreword,What is,S,ystem?,2024/10/12,10,ForewordHow they work,?,2024/10/12,11,Foreword,Filter the noise,2024/10/12,12,Foreword,Original information,After lowpass filtering,After highpass filtering,Image Processing,2024/10/12,13,Foreword,Example.Communication,Radio,signal,Transmitter,Receiver,intermediate,input,signal,Received,signal,output,signal,Text,Audio,Video,Electric,Electromagnetic,Text,Audio,Video,With Information,2024/10/12,14,Outline,1 Signals and Systems,2 Linear Time-Invariant Systems,3 Fourier Series Representation of Periodic Signals,3.03.5,3.6,3.7,3.8,3.9,3.10 3.11,4 The Continuous-Time Fourier Transform,5 The Discrete-Time Fourier Transform,5.05.5,5.6 5.8,6 Time and Frequency Characterization of Signals and Systems,6.1 6.4,6.56.7,7 Sampling,7.1 7.3,8 Communication System,8.1 8.2,9 The Laplace Transform,10 The Z-Transform,Note:,Contents,-Keypoints.,Contents-,Read by yourselves,.,2024/10/12,15,Signals and Systems,Continuous-time and discrete-time signals,Transformations of the Independent Variable,Exponential and Sinusoidal signal,The Unit Impulse and Unit Step Functions,Continuous-time and Discrete-time System,Basic System Properties,2024/10/12,16,1.1 Continuous-time and discrete-time signals,A.Examples,(1)A simple RC circuit,Source voltage Vs and Capacitor voltage Vc,(2)An automobile,Force,f,from engine,Retarding frictional force,V,Velocity,V(t),2024/10/12,17,1.1 Continuous-time and discrete-time signals,(4)A image signal,(3)A speech signal-,should we chase,2024/10/12,18,1.1 Continuous-time and discrete-time signals,B.Types of Signals,(1)Continuous-time Signal,(2)Discrete-time Signal,-,the independent variable is,continuous,-,the independent variable is,discrete,n is integer number,Sampling,Continuous-time discrete-time signals,1.1 Continuous-time and discrete-time signals,2024/10/12,20,1.1 Continuous-time and discrete-time signals,C.Representation of,Signal,(2)Graphical Representation,(1)Function Representation,Example:x(t)=cos,0,t,x(t)=e,j,0,t,n=0,2024/10/12,21,1 Signals and Systems 1.1.2 Signal Energy and Power,A.Energy(Continuous-time),Instantaneous power,:,Example,:,Let R=1 and,so,+,R,_,2024/10/12,22,1.1.2 Signal Energy and Power A.Energy(Continuous-time),Energy over t,1,t,t,2,:,Total Energy of signal:,Time_Average Power:,2024/10/12,23,1.1.2 Signal Energy and Power B.Energy(Discrete-time),Instantaneous power,:,Total Energy:,Time_Average Power,:,Energy over n,1,n,n,2,:,2024/10/12,24,1.1.2 Signal Energy and Power C.Finite Energy and Finite Power Signal,(Finite Total)Energy Signal,:,(Finite Average)Power Signal,:,Infinite Total Energy,Infinite Average Power Signal:,HW1-1,Read textbook P71:MATHEMATICAL REVIEW,HW1_1：P57-1.2 1.3(b)(c)(e)(f),2024/10/12,25,2024/10/12,26,1 Signals and Systems 1.2 Transformations of the Independent Variable,Time shift,Time reversal,Time-scaling,2024/10/12,27,1.2 Transformations of the Independent Variable 1.2.1 Examples of Transformations,Examples,t,0,0;Delay,A.Time Shift,2024/10/12,28,t,0,0,；,Delay,are identical in shape.,2024/10/12,29,1.2 Transformations of the Independent Variable B.Time Reversal,x(-t)or x-n:,Reflect
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