1.1 数字电路的基础知识 1.1.2 数制 1.1.1 数字信号和模拟信号 1.1.3 二进制代码

9.1 The Laplace Transform 1. The relationship 2. Region of Convergence（收敛域）

Chapter 8 Communication Systems Modulation : The general process of embedding an information -bearing signal into a second signal. Demodulation : Extracting the information-bearing signal. Modulation : Amplitude Modulation (AM) Frequency Modulation (FM) Phase Modulation (PM) Modulating

Let be a band-limited signal with then is uniquely determined by its samples if where

6.1 The Magnitude-Phase Representation （ 幅度-相位） of the Fourier Transform

4.1 Representation of Aperiodic Signals :The Continuous-Time Fourier Transform

1. Continuous-time system 2. Discrete-time system

2.1 Discrete-time LTI Systems : The Convolution Sum （卷积和） 2.1.1 The Representation of Discrete-Time Signals in Terms of impulses

1. is absolutely summable, 2. has finite energy

Chapter 1 Signals and Systems (1) A simple RC circuit Source voltage Vs and Capacitor voltage Vc (2) An automobile