低轨点波束增强实现区域定位阻断分析

Analysis on realization of regional positioning and blocking by low-orbit spot beam enhancement

针对导航出站信号易被恶意用户利用来获取定位信息的问题,在保证区域外导航服务正常使用的前提下,分析卫星功率增强信号在压制模式下的阻断效果及实施条件:分析通过低轨卫星(LEO)增强实现区域定位阻断的模型,并研究区域定位阻断的评估方法;然后将用户接收等效载噪比做为评估定位阻断性能的核心指标;最后给出相应的载噪比门限的计算方法,用最小星上天线增益评价阻断实施条件。分别对二进制偏置载波(BOC)(1,1)、四相移相键控(QPSK)(10)和二相移相键控(BPSK)(5)调制信号进行阻断仿真。结果表明,对于低轨卫星实施的增强信号,至少需要15.69 dB的最小星上天线增益;星上增益大小与信号体制、播发干扰类型有关,也取决于信号的抗干扰能力;对于QPSK(10)调制信号,带限白噪声干扰需要27.93 dB的最小星上天线增益。

Aiming at the problem that it is easy to be used by malicious users to obtain location information for navigation outbound signals,under the premise of ensuring the normal use of navigation services outside the area,the paper analyzed the blocking effect and implementation conditions of satellite power enhancement signals in the suppression jamming mode:the model of realizing regional positioning blocking through low Earth orbit(LEO)satellite enhancement was analyzed,and the evaluation method of regional positioning blocking was studied;then the user-received equivalent carrier-to-noise ratio was used as the core index for evaluating positioning blocking performance;finally the calculation method of the corresponding carrier-to-noise ratio threshold was given,and the minimum on-board antenna gain was used to evaluate the blocking implementation conditions.Blocking simulations were performed for binary offset carrier(BOC)(1,1),quadrature phase shift keying(QPSK)(10)and binary phase shift keying(BPSK)(5)modulated signals,respectively.Results showed that for the enhanced signals implemented by LEO satellites,a minimum on-board antenna gain of 15.69 dB would be required;and the on-board gain would be related to the signal system and broadcast interference type,and also depend on the anti-jamming capability of the signal;moreover,for QPSK(10)modulated signals,band-limited white noise interference would require a minimum on-board antenna gain of 27.93 dB.