基于双门限的变换域通信系统基函数设计

针对单门限变换域通信系统往往无法兼顾抗干扰和隐蔽通信的问题,提出了一种基于双门限变换域通信系统基函数幅度谱的设计方法。该方法首先在干扰存在情况下进行单门限系统最优误码率门限与最差误码率门限的判断，然后通过参数灵活调整两个门限的值，将大于高门限和低于低门限的值分别设为0和1，位于双门限之间的频谱进行倒置，得到的基函数通过对数据进行调制实现通信。仿真结果表明：相比于单门限变换域通信系统，通过参数调节后的双门限变换域通信系统可以同时具有良好的抗干扰及隐蔽通信性能。

Design of basis function for transform domain communication system based on double-threshold

For the problem that single threshold transform domain communication system(TDCS) cannot possess anti-jamming and covert communication property at the same time,a method of designing the spectrum amplitude of basis function based on double-threshold is proposed in transform domain communication system.With the coexistence of jamming,the thresholds of optimal and worst bit error rate(BER) are judged,then by adjusting the two thresholds through parameter,the spectrum amplitude above the upper threshold is marked as 0,below the lower threshold is marked as 1,while between the double thresholds,the spectrum amplitude is inverted,and finally TDCS implements communication by modulating data on the basis function.Simulation results show that compared with single-threshold transform domain system communication,the double-threshold TDCS through adjusting the parameter can achieve good performance of anti-jamming and covert communication at the same time.