调制解调器与模拟线路的数字通信

• 作 者: 张书杰
• 出 处: 网上出版
• 发表日期: 1998年02期
• 关键词: 模拟线 低频成分 拨号上网 基带信号 信息世界 载波信号 数据压缩 二进制信号 命令集 相位调制

随着Internet在国内的日益普及,拨号上网作为一种简单易行的方式开始被越来越多的个人用户采纳,通过一台调制解调器(Modem)驳入电话网,普通用户就可以在自己的微机上遨游无穷无尽的Internet信息世界。但是,我们知道,数据通过微机输出的是二进制的“0”或“1”的电压(电流)信号(基带信号),其中含有直流和大量的低频成分,往往通不过电话电路传输(电话网的频带范围一般为300-3400Hz),那么,通过普通电话网(模拟线路)为什么还能够实现计算机

With the increasing popularity of the Internet in the country, dial-up Internet access as a simple and easy way to begin to be more and more individual users to adopt, through a modem (Modem) split into the telephone network, ordinary users can own computer Travel endless Internet information on the world. However, we know that the data output by the microcomputer is a binary “0” or “1” voltage (current) signal (baseband signal) containing DC and a large number of low frequency components, often passing through the telephone circuit Frequency range is generally 300-3400Hz), then, through the ordinary telephone network (analog line) Why can also achieve computer