基于改进Chebyshev混沌映射的抗比相法IFM测频信号设计

Anti-IFM Frequency Measurement Signal Design Based on Improved Chebyshev Chaotic Mapping

为了降低雷达发射信号的载频被瞬时测频(Instantaneous Frequency Measuring, IFM)截获的概率,基于抗IFM接收机信号的设计原理,提出了一种运用新型混沌映射产生的强随机、宽间隔频率捷变序列的方法,对线性调频连续波信号(Linear Frequency Modulated Continuous Wave, LFMCW)的载频进行调制,设计了一种抗IFM测频信号。仿真结果表明,所提混沌映射具有强随机性以及高复杂度,并且IFM接收机对所设计信号载频进行测量时,90.5%的测量结果与真实值的绝对误差大于200 MHz, 77.5%的测量结果与真实值的绝对误差大于500 MHz,表明所设计的信号具有较好的抗截获性能,抗IFM测频效果良好。

In order to reduce the probability that is intercepted by Instantaneous frequency measuring(IFM),according to the carrier frequency of radar transmitted signal a novel method of strong random and wide-interval frequency agile sequence generated by chaotic mapping based on the design principle of anti-IFM receiver signal is proposed to modulate the carrier frequency of linear frequency modulated continuous wave(LFMCW).An anti-IFM frequency measurement signal is designed.The simulation results show that the proposed chaotic mapping has strong randomness and high complexity,and when IFM receiver measures the designed signal carrier frequency,the absolute error between 90.5%of the measured results and the true value is greater than 200 MHz,and the absolute error between 77.5%of the measured results and the true value is greater than 500 MHz.The results show that the designed signal has good anti-interception performance and good anti-IFM frequency measurement effect.