以下是引用MCV在2003-1-15 16:30:00的发言:
今天心情好得很,在书上抄一段原文给你看
在数字通信系统中,为了恢复发送信息,必须对调制器输出进行周期性的抽样,每个符号间隔抽样一次。因为在接收机中对发送机到接收机的传播延时一般是未知的,为了对解调器输出同步抽样,必须从接收信号中导出符号定时
《数字通信》第三版,[美]john G.Proakis著。
我这里还有原版的,要不要也抄一遍?
We have observed that in a digital communication system, the output of the demodulator must be sampled periodically, once pre symbol interval, in order to reover the transmitted information. Since the propagation delay from the transmitter ti the reciver is generally unknown at the receiver, symbol timing must be derived from the received signal in order to synchronously sample the output of the demodulator.
"Digital Communication" Fourth Edition John G.Proakis
呵呵我辛辛苦苦抄了教科书来教育你,你居然不看。
怪不得你自称耐心好,或者说和你讨论的人耐心都不好,佩服,佩服!
[此贴子已经被作者于2003-1-15 16:46:38编辑过] |