摘要数字信号的传输方式分为基带传输和频带传输，在数字频带传输系统中，基带数字信号对高频载波的一些参量进行调制，以使已调信号与信道的特性相匹配。 通过信道传输，在接收端对已调信号解调判决后恢复成数字信号。数字频带传输 系统的建模与设计通过对于 2ASK、2FSK、2PSK 调制解调的 VHDL 语言的设计，运 用 Quartus Ⅱ软件进行编译和仿真，程序经过编译和仿真完全正确后将程序下载 到 SmartSOPC 实验平台中，在硬件上实现 2ASK、2FSK、2PSK、调制解调的功能，68434

完成对于数字频带传输系统的建模与设计。

关键字：2ASK 2PSK 2FSK 调制 解调

itle The Modeling and Design of digital band system

Abstract

Digital signal ’ s mode of transmission can be pided into baseband transmission and band transmission. In digital band transmission system,some parameters of high frequency carrier is modulated with the modulated signal so that the modulated signal matches the characteristics of the channel. Through channel transmission,the demodulated signal returns to digital baseband signal after the recipient demodulation and judgment.With the design of VHDL language to modulate and demodulate 2ASK、 2FSK and 2PSK , the modeling and design of digital band system is realized. With the Quartus II to compile and simulate the program , the program is downloaded into the SmartSOPC experimental platform ,then the modulation and demodulation function of 2ASK, 2FSK, 2PSK, modulation and demodulation is achieved on the hardware.Finally, the modeling and design of digital band system is accomplished.

Keywords 2ASK 2PSK 2FSK modulation demodulation VHDL modeling

目 次

1 引言 1

1．1 设计的意义与背景 1

1. 2  课题设计的主要内容 1

2 数字频带传输系统原理 1

2.1  基于 DDS 载波信号发生器原理 1

2.2 m 序列发生器原理 2

2.3 二进制振幅键控（2ASK）调制、解调原理 3

2.3.1 2ASK 调制 3

2.3.2 2ASK 解调 4

2.4 二进制频移键控（2FSK）调制、解调原理 5

2.4.1 2FSK 调制 5

2.4.2 2FSK 解调 6

2.5 二进制相移键控（2PSK）调制、解调原理