文中提出了一种在直扩系统中建立低速隐蔽信道的方法,并对其性能进行了分析;对隐蔽信道的应用进行了探讨,并给出了相关的实验结果。具体实现时,先利用一个较短的PN码对隐蔽信道的符号进行扩频调制,然后利用业务信道扩频码的一部分对一次扩频后的符号进行二次扩频调制。由于隐蔽信道经过了两次扩频,因此可以获得非常好的抗截获性能。 In this paper, a method of establishing low-speed covert channel in DSSS system is proposed and its performance is analyzed. The application of covert channel is discussed, and the related experimental results are given. In specific implementation, a shorter PN code is first used to spread-spectrum modulate the symbols of the covert channel, and then a second spread spectrum modulation is performed on the symbols after the first spreading by using a part of the service channel spreading code. Since the covert channels are spread twice, very good anti-interception performance can be obtained.