文档介绍：1 Signal and System
Continuous-time and discrete-time signals
Examples and Mathematical Representation
A. Examples
(1) A simple RC circuit
Source voltage Vs and
Capacitor voltage Vc
1. Signals and Systems
1 Signal and System
(2) An automobile
Force f from engine
Retarding frictional force ρV
Velocity V
1 Signal and System
(3) A Speech Signal
1 Signal and System
(4) A Picture
1 Signal and System
(5) Vertical Wind Profile
1 Signal and System
B. Types of Signals
(1) Continuous-time Signal
1 Signal and System
(2) Discrete-time Signal
1 Signal and System
C. Representation
(1) Function Representation
Example: x(t) = cos0t
x(t) = ej 0t
(2) Graphical Representation
Example: ( See page before )
1 Signal and System
Signal Energy and Power
A. Energy (Continuous-time)
Instantaneous power:
Let R=1Ω, so
p(t)=i2(t)=v2(t)=x2(t)
1 Signal and System
Energy over t1 t t2:
Total Energy:
Average Power: