GPS信号的脉冲干扰效能分析

脉冲干扰广泛存在于现代战场电磁环境中。为了提升脉冲干扰在导航对抗中的应用效率，根据GPS接收机工作过程，以干扰等效载噪比和码跟踪误差作为干扰效果评估指标，对脉冲干扰参数影响下的离散谱特征C/A码信号和连续谱特征M码信号的干扰效果评估指标分别进行了理论推导和仿真分析。为确保干扰效果，对于C/A码信号，脉冲干扰频偏可根据C/A码PRN#信息预先计算比较得到，脉冲重复周期设置为1 ms，脉宽在0.01~0.05 ms取值；对于M码信号，脉冲干扰频偏可依据单频干扰频偏设置预先计算平均得到，通过减小脉冲重复周期和提高脉冲幅度来保证干扰效果，在脉冲重复周期固定时，占空比在0.002~0.005取值。该结论揭示了脉冲干扰对GPS信号的影响本质，对提高干扰利用效率具有借鉴意义。

Effect Analysis of Pulse Jamming against GPS

Pulse jamming is widely used in electromagnetic environment of modern battlefield. In order to improve pulse jamming application efficiency in navigation countermeasure, the theoretical derivation and numerical simulation about jamming effect evaluation indexes of discrete spectrum C/A code signal and continuous spectrum M code signal are performed respectively under the influence of pulse jamming parameters, which are based on the process of GPS receiver and evaluated by indexes of jamming efficient carrier-to-noise ratio and code tracking error. To ensure effect of jamming, for the C/A code signal, pulse jamming frequency offset can be preset after calculating and comparing by acquiring PRN number information of C/A code, pulse repetition period can be set to 1ms and pulse duration can take value between 0.01~0.05 ms, but for the M code signal, the jamming frequency offset can be preset after calculating and averaging according to the method of acquiring single frequency jamming frequency offset, the jamming effect can be ensured by decreasing pulse repetition interval and increasing pulse amplitude, when the pulse repetition interval is fixed, pulse duty cycle can take value between 0.002~0.005. The conclusion reveals the influence essence of pulse jamming to GPS signal, which is significant for improving pulse jamming application efficiency.