上海交通大学：《数字信号处理 Digital Signal Processing（B）》教学资源_Handouts_ch1_Review for Signal and System

Introduction To Digital Signal Processing 主讲：张君 上浒充大

Introduction To Digital Signal Processing 主讲：张君

Classification of Signals Introduction to Digital Signal Processing--Review for Signal and System Continuous signals vs.discrete signals Real signals vs.complex signals Scalar signals vs.vector signals One dimensional signals vs.multi- dimensional signals *Deterministic signal vs.random signal 上游充通大

Classification of Signals Continuous signals vs. discrete signals Real signals vs. complex signals Scalar signals vs. vector signals One dimensional signals vs. multi￾dimensional signals Deterministic signal vs. random signal Introduction to Digital Signal Processing——Review for Signal and System

Classification of Signals HAO TO Introduction to Digital Signal Processing--Review for Signal and System A continuous-time signal with a continuous amplitude is usually called an analog signal A discrete-time signal with discrete- valued amplitudes represented by a finite number of digits is referred to as the digital signal A discrete-time signal with continuous valued amplitudes is called a sampled- data signal A digital signal is thus a quantized sample data signal 上浒充通大

Classification of Signals A continuous-time signal with a continuous amplitude is usually called an analog signal A discrete-time signal with discrete￾valued amplitudes represented by a finite number of digits is referred to as the digital signal A discrete-time signal with continuous valued amplitudes is called a sampled￾data signal A digital signal is thus a quantized sample data signal Introduction to Digital Signal Processing——Review for Signal and System

Classification of Signals Introduction to Digital Signal Processing--Review for Signal and System Amplitude Amplitude Time,t Time,t A continuous-timesignal A digital signal Amplitude Amplitude Time,t Time,t A quantized boxcar signal A sampled-data signal 上游充通大

Classification of Signals Introduction to Digital Signal Processing——Review for Signal and System

Representation of Signals Introduction to Digital Signal Processing--Review for Signal and System For a continuous-time 1-D signal,the continuous independent variable is usually denoted by t For a discrete-time 1-D signal,the discrete independent variable is usually denoted by n 上游充通大

Representation of Signals For a continuous-time 1-D signal, the continuous independent variable is usually denoted by t For a discrete-time 1-D signal, the discrete independent variable is usually denoted by n Introduction to Digital Signal Processing——Review for Signal and System

Representation of Signals Introduction to Digital Signal Processing--Review for Signal and System In many applications,a discrete-time signal is generated by sampling a parent continuous time signal at uniform intervals of time If the discrete instants of time at which a discrete-time signal is defined are uniformly spaced,the independent discrete variable n can be normalized to assume integer values 上游充通大

Representation of Signals In many applications, a discrete-time signal is generated by sampling a parent continuous time signal at uniform intervals of time If the discrete instants of time at which a discrete-time signal is defined are uniformly spaced, the independent discrete variable n can be normalized to assume integer values Introduction to Digital Signal Processing——Review for Signal and System

Typical Signal Processing Operations Introduction to Digital Signal Processing--Review for Signal and System Most signal processing operations in the case of analog signals are carried out in the time domain In the case of discrete-time signals, both time domain or frequency-domain operations are usually employed 上游充通大

Typical Signal Processing Operations Most signal processing operations in the case of analog signals are carried out in the time domain In the case of discrete-time signals, both time domain or frequency-domain operations are usually employed Introduction to Digital Signal Processing——Review for Signal and System

Elementary Time-Domain Operations Introduction to Digital Signal Processing--Review for Signal and System Three most basic time-domain signal operations are scaling,delay,and addition Three other elementary operations a are integration,differentiation and product Filtering is used to pass certain frequency components in a signal through the system without any distortion and to block other frequency components 上游充通大

Elementary Time-Domain Operations Three most basic time-domain signal operations are scaling, delay, and addition Three other elementary operations are integration , differentiation and product Filtering is used to pass certain frequency components in a signal through the system without any distortion and to block other frequency components Introduction to Digital Signal Processing——Review for Signal and System

Typical Signal Processing operations Introduction to Digital Signal Processing--Review for Signal and System Modulation and Demodulation Multiplexing and Demultiplexing Quadrature Amplitude Modulation Signal Generation 上游充通大

Typical Signal Processing operations Modulation and Demodulation Multiplexing and Demultiplexing Quadrature Amplitude Modulation Signal Generation Introduction to Digital Signal Processing——Review for Signal and System

signal representation based on 6(t) Introduction to Digital Signal Processing--Review for Signal and System Any signal can be represented by a shifted weight sum ofδ(t) f(t) k△T Approximate f(t)with a serial of rectangles.For the rectangle near t=kAT,the duration is AT,the high is f(k△T),and the area is f(k△T)△T.So the rectangle can be represented by f(k△T)△Tδ(t- k△T) f(t)≈∑f(k△r)A(t-k松r) k三-00 上游充通大

Introduction to Digital Signal Processing——Review for Signal and System signal representation based on δ(t)  Any signal can be represented by a shifted weight sum of δ(t) Approximate f(t) with a serial of rectangles. For the rectangle near t=kΔτ , the duration is Δτ, the high is f(kΔτ ), and the area is f(kΔτ ) Δτ . So the rectangle can be represented by f(kΔτ ) Δτ δ(t - kΔτ ) f(t) kΔT ( )   (  )(   )   f t f k t k k