分布式间歇干扰下基于SMI的GNSS空时自适应处理器性能分析

Performance analysis of SMI based GNSS space-time adaptive processing under distributed intermittent interferences

针对全球导航卫星系统接收机面临的分布式间歇干扰威胁,全面准确地分析了基于采样矩阵直接求逆方法的空时自适应处理(space-time adaptive processing,STAP)的抗干扰性能。在建立性能分析模型的基础上,根据间歇干扰造成的采样协方差矩阵不匹配情况,通过分类评估、梳理归纳、理论推导全面分析了不同情况下STAP的性能。分析结果表明在采样长度小于闪烁周期且使用预采用处理方法时,空时自适应处理器会出现漏采样,干扰抑制性能会急剧下降,漏采样出现的频率为各干扰闪烁频率之和。数值和仿真分析验证了理论分析的结果,在此基础上讨论了考虑分布式间歇干扰时STAP的优化设计。

Considering the distributed intermittent interference threat faced by global navigation satellite system receiver,the anti-jamming performance of STAP(space-time adaptive processing) based on sample matrix inversion method was comprehensively and accurately analyzed.Based on the performance analysis model,according to the mismatch of sampling covariance matrix caused by intermittent interferences,the performance of STAP under different conditions was comprehensively analyzed through classification evaluation,combing induction and theoretical derivation.The analysis results show that when the sampling length is less than the scintillation period and the pre-sample method is used,the missed sampling of space-time adaptive processor will occur and the interference suppression performance will decrease sharply,and the frequency of missed sampling is the sum of the scintillation frequencies of each interference.Numerical and simulation analyses verify the results of analysis,and based on this,the optimal design of STAP in the face of distributed intermittent interference is discussed.