论文部分内容阅读
在用于时分增量编码交换体制的呼叫系统中,电话机包括一个△M调制解调器以及一个呼叫键盘,该键盘用来发送二进制码表示的呼叫号码。呼叫号码包括一种可变的呼叫脉冲组合、两种固定脉冲组合,其中一种固定脉冲组合用于可变呼叫脉冲的组帧,另一固定脉冲组是位于呼叫脉冲前的一组预定的具有相同值的识别码组,它给呼叫脉冲组合的辨认作出一个标记。由于在一侧的呼叫脉冲和组帧脉冲的比特流以及识别脉冲流的比特流同另一侧的△M的编码脉冲具有相同的频率,因此必须采取措施来分离它们。在交换电路中,用一个计数器对识别脉冲组的数字进行计数,并控制一个开关电路,将△M编码脉冲流及呼叫号码的比特流直接分开。
In a call system for a time-division-incremental code switching architecture, the telephone includes an AM modem and a call keypad which is used to send the call number in binary code. The call number includes a variable call pulse combination, two fixed pulse combinations, one fixed pulse combination being used for framing the variable call pulse and the other fixed pulse set being a set of pre-set Identical value identification code group, which marks the identification of the call pulse combination. Since the bit stream of the call pulse and the framing pulse and the bit stream of the identified pulse stream on the one side have the same frequency as the coded pulse of ΔM on the other side, measures must be taken to separate them. In the switching circuit, a counter counts the number of identification pulse groups and controls a switching circuit to separate the ΔM encoded pulse stream and the bit stream of the calling number directly.