脉冲和窄带混合干扰对卫星导航终端抗干扰的影响分析

Analysis of the Influence of Pulse and Narrowband Mixed Interference on the Anti-jamming of Satellite Navigation Terminal

卫星导航终端面临着严重的干扰问题,虽然单一的脉冲或窄带干扰很难对具有抗干扰功能的卫星导航终端产生影响,但是现有的抗干扰结构很难抑制脉冲与窄带的混合干扰。为了分析混合干扰对卫星导航终端抗干扰的影响,给出了脉冲与窄带及其混合干扰的数学模型,介绍了优先抑制窄带干扰和优先抑制脉冲干扰两种顺序抗干扰结构,基于该模型分析了不同脉冲干扰占空比下混合干扰对抗干扰后载噪比的影响。根据仿真实验,当两个干扰的干噪比均为30dB时,混合干扰造成抗干扰后载噪比下降约5 dB。研究表明,在采用传统抗干扰结构的情况下,脉冲与窄带混合干扰对卫星导航终端抗干扰性能影响较大,其影响大于单一脉冲或窄带干扰影响的简单叠加,不同脉冲干扰占空比组成的混合干扰造成的载噪比损耗大于5 dB,影响卫星导航信号捕获跟踪性能。

Satellite navigation terminals are faced with serious interference problems. Although single pulse or narrowband interference is difficult to affect the satellite navigation terminals with anti-jamming function,the mixed interference of pulse and narrowband can still play the role. In order to analyze the influence of the mixed interference of pulse and narrowband on the anti-jamming of satellite navigation terminal,this paper presents the mathematical model of the mixed interference,and analyzes two traditional sequential anti-jamming structures of priority suppression of narrowband interference and priority suppression of pulse interference. Based on the model,the influence of mixed interference with different parameter settings on the anti-jamming of satellite navigation terminal is analyzed. According to the theoretical analysis and simulation,when the interference to noise ratio is 30 dB,the mixed interference causes the carrier-to-noise ratio to decrease by 5 dB. The results show that when the traditional sequential anti-jamming structure is adopted,the mixed interference of pulse and narrowband has a big influence on the anti-jamming performance of satellite navigation terminal,which is greater than the summation of single pulse or narrowband interference. The loss of carrier-to-noise ratio caused by different duty ratio of pulse interference reaches 5 d B,which plays a bad role in the processing of acquisition and tracking.