Research On Radar Anti Jamming Technology Based On Waveform Agility

Because there is a great correlation between the active deception jamming and the transmitted signal, it caused a great disturbance to signal processing of pulse compression and other related receiving radar. In this thesis, the main means of jamming are analyzed. Based on the forwarding mechanism of digital radio frequency memory,the anti-active deception jamming is proposed by using the waveform agility technique. Has maked waveform agility to the most commonly used two kinds of pulse compression signal linear frequency modulation signal and coded signal, The emission waveforms of random agility and mutual orthogonality are designed, in order to realize the anti-active deception jamming of radar.(1)Starting from the three parameters of the modulation frequency, the initial phase and the center frequency, Three agile LFM(Linear Frequency Modulation) signals with good orthogonality and anti-jamming are studied. Frequency agile LFM signal and random initial phase with frequency modulation hopping signal of linear frequency modulation, orthogonal frequency division LFM signal. The matching technology of waveform group is proposed.(2)Using the genetic algorithm to design the phase coding, frequency coding, phase coding and linear frequency modulation signal transmission and the influence of the number of waveforms and the length of the code on orthogonality is analyzed. It is proved that the agility based on coded signal can restrain all kinds of jamming by simulation. The Doppler compensation technique of pulse pressure after advanced line velocity measurement is studied. The Doppler sensitivity of coded signals is solved fundamentally.(3)Because of the limitation of genetic algorithm, the chaotic signal is applied to the design of coded signal. The three kinds of orthogonal transmitting wave sets are studied, which are chaotic phase coding, chaotic frequency coding and chaotic phase frequency coding. And the simulation results show that these three kinds of signals have very good anti-jamming performance.