Data rate of multiplexed line is fixed If one channel receiver can not receive data, the others must carry on The corresponding source must be quenched This leaves empty slots
12 voice channels (4kHz each) = 48kHz Range 60kHz to 108kHz
精选课件
Analog Carrier Systems(2)
Supergroup(超群)
60 channel FDM of 5 group signals on carriers between 420kHz and 612 kHz
精选课件
Frequency Division Multiplexing(2)
Carrier frequencies separated so signals do not overlap (guard bands) 载波频率要相互隔离使信号不重叠(防护频带) e.g. broadcast radio Channel allocated even if no data
Data and Computer Communications
Chapter 8 Multiplexing
精选课件
多路复用
为充分利用通信干线的传输容量,常采用 多路复用技术。多路器(复用器)组合N路 输入线路上的数据,通过一条高容量的数据 链路传输;分路器接收到复用的数据流,按 通道分离(分路)这些数据,把它们送到适当 的输出线路上。
m1(t)
Ssc1(t) 子载波fsc1