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移动电话使用方便,用户愈来愈多,而频率资源却有限。怎样将有限的频率资源提供给日益增多的移动电话用户呢?目前,有两个很有发展前途的信道复用方式,即:时分复用(TDMA—Time Division MultipleAccess)和码分复用(CDMA—CODE Division MultipleAccess)。下面做一简要介绍。 1、时分复用 所谓时分复用,就是按一定的时间顺序,在一个信道上轮流传输各路信号,如附图所示。 假设有8路等待传输的信号轮流使用一个信道的公共传输线,由于机键是同步工作的,即发送端机键在“1”位置时,接收端机键也在“1”位置,以下“2”、“3”…
Mobile phones are easy to use, more and more users, and frequency resources are limited. How to provide limited frequency resources to a growing number of mobile phone users? Currently, there are two very promising channel reuse modes, namely Time Division Multiple Access (TDMA-Time Division Multiple Access) and Code Division Multiple Access (CDMA -CODE Division MultipleAccess). Make a brief introduction below. 1, time division multiplexing The so-called time-division multiplexing, is a certain time sequence, in a channel on the transmission of various signals in turn, as shown in the figure. Suppose there are 8 channels waiting to be transmitted. The common transmission line of a channel uses the common transmission line of the channel. Since the keys are working synchronously, the transmitter key is in the “1” position and the receiver key is in the “1” “,” 3 "...