针对短波3G-ALE信号的改进脉冲干扰性能研究

Research on the Performance of Modified Pulse Jamming Against HF 3G-ALE Signal

针对美军新一代短波3G-ALE信号为提高其协议信息传输可靠性而在通信链路层进行的多重数据编码,提出一种改进脉冲干扰方法。首先利用公开的伪随机扰码,建立对周期脉冲信号进行伪随机预加扰的干扰模型;之后推导信号接收处理公式,在此基础上分析脉冲占空比、脉冲周期等干扰参数,以及扰码失步、干扰频偏等因素对于干扰性能的影响;最后仿真干扰实验并得到相关结论。实验结果验证改进脉冲干扰对于3G-ALE信号协议信息可靠传输的干扰有效性,在设置脉冲占空比75%、脉冲周期使得脉冲持续时间等于整数倍符号长度T_B时的干扰效果最佳;2T_B以内的扰码失步、80 Hz以内的干扰频偏导致的干扰效果下降,则可以通过提高干信比较好地予以克服。

In view of the new generation HF 3G-ALE signal applied in US Army to multiple data encoding on communication link layer to improve the transmission reliability of its protocol information, a modified pulse jamming method is proposed against such multiple data encoding. Firstly, a jamming model affected on the periodic pulse signal which can be in advance scrambled by public pseudo random scrambling sequence is built up. Then, on the basis of formula derivation for signal receiving and processing, the impacts on jamming performance are analyzed from some jamming parameters such as pulse duty ratio and pulse period, along with other parameters such as scrambling sequence's missynchronization and jamming frequency offset. Finally, this jamming method is carried on simulation experiment, resulting in some relevant conclusions. The experiment results prove the effectiveness of the modified pulse jamming against the reliable transmission of 3G-ALE signal protocol information. The jamming effect is the best when the pulse duty ratio is set 75 % and the pulse period is set to make pulse duration equal to integer multiple symbol time length Tb. The decline of jamming effect resulting from scrambling sequences missynchronization within 2Tb or jamming frequency offset within 80 Hz, can be improved fairly by increasing the jamming-tosignal power ratio.