Chapter 2 Discrete-Time Signals and Systems
Chapter 2 Discrete-Time Signals and Systems
82.1 Discrete-Time Signals Time-Domain Representation Signals represented as sequences of numbers, called samples Sample value of a typical signal or sequence denoted as x n with n being an integer in the range-0≤n≤o xn defined only for integer values of n and undefined for noninteger values of n Discrete-time signal represented by xn
§2.1 Discrete-Time Signals: Time-Domain Representation • Signals represented as sequences of numbers, called samples • Sample value of a typical signal or sequence denoted as x[n] with n being an integer in the range - n • x[n] defined only for integer values of n and undefined for noninteger values of n • Discrete-time signal represented by {x[n]}
82.1 Discrete-Time Signals Time-Domain Representation Discrete-time signal may also be written as a sequence of numbers inside braces: {x[n}={…,-0.2,2.2,1.1,0.2,3.7,2.9,…} 个 The arrow is placed under the sample at time index=o In the above, x 1=-0. 2, X0=2. 2, x[1]l=1.1,etc
§2.1 Discrete-Time Signals: Time-Domain Representation • Discrete-time signal may also be written as a sequence of numbers inside braces: {x[n]}={…,-0.2,2.2,1.1,0.2,-3.7,2.9,…} • The arrow is placed under the sample at time index n = 0 • In the above, x[-1]= -0.2, x[0]=2.2, x[1]=1.1, etc
82.1 Discrete-Time Signals Time-Domain Representation Graphical representation of a discrete-time signal with real-valued samples is as shown below: x5] xin] 3456789101112 -10-9-8-7-6-5-4-3-2-1012 1314151617 x3]
§2.1 Discrete-Time Signals: Time-Domain Representation • Graphical representation of a discrete-time signal with real-valued samples is as shown below:
82.1 Discrete-Time Signals Time-Domain Representation In some applications, a discrete-time sequence xinl may be generated by periodically sampling a continuous-time signal xa(t) at uniform intervals of time xa(-57 T 0 T 37)
§2.1 Discrete-Time Signals: Time-Domain Representation In some applications, a discrete-time sequence {x[n]} may be generated by periodically sampling a continuous-time signal xa (t) at uniform intervals of time