Chapter 1 Signals and Systems (5)Vertical Wind profile 26 24 22 20 18 916 复14 B 10 02004006008001,0001,2001,4001,600 Height(feet) 11
11 (5) Vertical Wind Profile Chapter 1 Signals and Systems
Chapter 1 Signals and systems 信号与系统分析的两个共同的基本点: 1.信号(一个或多个自变量) 2.系统:对给定的信号作出响应,并产生新的信号 信号可表示成一个或多个自变量的函数; 电压v() (xy2x电流1() 信号时间特性 的描述 频率特性 12
12 信号 的描述 频率特性 信号可表示成一个或多个自变量的函数; f (x, y,z,t) 电压 电流 v(t) i(t) 信号与系统分析的两个共同的基本点： 2. 系统：对给定的信号作出响应，并产生新的信号 Chapter 1 Signals and Systems 1. 信号（一个或多个自变量） 时间特性
Chapter l Signals and Systems 5 11 Continuous-Time and Discrete-Time Signals 连续时间信号和离散时间信号 9 1.1.1 Examples and Mathematical Representation 1. Continuous-Time signals The independent variable is continuous f() f() 0 0
13 § 1.1 Continuous-Time and Discrete-Time Signals 连续时间信号和离散时间信号 § 1.1.1 Examples and Mathematical Representation 1. Continuous-Time Signals —— The independent variable is continuous 0 t f (t) 0 t f (t) Chapter 1 Signals and Systems
Chapter 1 Signals and Systems 2. Discrete-Time Signals - The independent variable is discrete IG n is integer number 4 01234567 Continuous-time signals Discrete-time signals 14
14 Chapter 1 Signals and Systems 2. Discrete-Time Signals —— The independent variable is discrete xn n 0 5 1 1 2 3 4 5 6 4 1 7 10 8 11 n is integer number Continuous-time signals Discrete-time signals
Chapter l Signals and Systems 5 1.1.2 Signal Energy and Power 1. Instantaneous power(瞬时功率) 2. Total energy 3. Time-averaged power(平均功率) x XX 0 0 0 t Energy signal Power signal 15
15 Chapter 1 Signals and Systems 3. Time-averaged power（平均功率） Energy signal 0 t x(t) 0 t x(t) Power signal 0 t x(t) 1. Instantaneous power（瞬时功率） 2. Total energy § 1.1.2 Signal Energy and Power