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

‍ ‍‍ ‍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 dB， which plays a bad role in the processing of acquisition and tracking.