Study On Anti-jamming Waveform Design Of MIMO Radar

With the application of Digital Radio Frequency Memory(DRFM),it is easier to realize the jamming which is correlated with the radar transmitting signal.The Jammer uses DRFM technology to sample,store and modulate the intercepted radar signal,which can form false targets and make it difficult for the radar to determine the true target information,thus seriously affecting the radar performance,especially for the interference coming from the main lobe,it can not be suppressed by the method of beamforming,so it is more difficult to resist.MIMO(Multiple Input Multiple Output)radar can distinguish the transmitted signals of each element at the receiving end,which improves the target detection performance and electronic countermeasure capability of the radar,and has higher waveform design freedom.In this thesis,from the point of view of waveform design,the methods of MIMO radar to counter the main-lobe deception jamming are studied.The main work is as follows:The design method of anti-jamming waveform based on waveform agility is studied.Waveform agility is an effective method to deal with deceptive interference,and the large-time-bandwidth product signal has good low interception performance,the design methods of orthogonal waveform and hybrid coding are studied and the waveform performance is analyzed.The design method of pulse-to-pulse phase coding anti-deception jamming waveform is studied.The number of quadrature waveforms needed for MIMO radar is doubled by applying waveform agility to MIMO radar,which increases the difficulty of waveform design.In order to solve this problem,pulse-to-pulse phase coding and pulse-to-pulse waveform agility are adopted to distinguish the element signals.In order to solve the problem that the time-to-time random phase coding is not effective against velocity deception,the quasi-Newton algorithm is used to optimize the inter-pulse phase coding and the space-time phase coding.The anti-jamming performance of the designed waveform is analyzed.The anti-reconnaissance performance of waveform is analyzed from the point of anti-interception and anti-recognition.The performance of anti-range deception jamming and anti-velocity deception jamming under different scenarios is analyzed by simulation.The method of pulse-to-pulse phase coding to distinguish different element signals and pulse-to-pulse waveform diversity to resist range deception jamming reduces the number of orthogonal waveforms and distributes the jamming energy in the whole Doppler domain,the anti-jamming performance of radar is improved.The optimized inter-pulse phase coding changes the distribution of jamming energy in the Doppler domain,so that the radar can detect the target when the jamming is strong.The space-time phase coding method improves the anti-jamming performance of radar by adjusting the direction of jamming signal equivalent transmitting beam pattern.