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用两片语音电路可以组成最简数字通信系统。发话方将语音电路置于存贮状态,但输出的数字信号并不进入贮存器而是传送到收信方。收信方则将语音电路置于放音状态,同样转换的数字信号来自发信方。数传通信有如下优点:①在相当宽的范围内,信噪比不变;②保密性强,并可以用数字方式进一步加密;③可以很容易地扩展功能,如自动应答、语言存贮等;④无线方
With two voice circuits can be composed of the most simple digital communication system. The caller places the voice circuit in a storage state, but the digital signal that is output does not go to the storage but to the recipient. The receiver places the voice circuit in playback mode, and the same converted digital signal comes from the sender. Digital communications have the following advantages: ① a relatively wide range, the same signal to noise ratio; ② strong confidentiality, and can be digitally further encrypted; ③ can be easily extended functions, such as automatic answering, language storage ; ④ wireless side