Cognitive Radar Mainlobe Jamming Suppression Methods Via Multidimensional Signal Design And Processing

In the future electromagnetic spectrum warfare,radar usually works in complex electromagnetic environment.The mainlobe jamming enters the receiver from the main beam of the radar antenna,which aims to making deceptive or suppressive effect and reduces the performance of radar system significantly.Therefore,the research on mainlobe jamming suppression can improve the detection performance of radar in complex electromagnetic environment,and is the core technology for the acquisition of electromagnetic superiotrity in the electromagnetic spectrum warfare.In recent years,cognitive radar masters the initiative of multidimensional agility such as space,time,frequency and polarization through continuous cooperative feedback between the transmit waveform and receive processing,which has great potential and advantage to resist mainlobe jamming.To this end,this dissertation focuses on cognitive radar mainlobe jamming suppression methods via multidimensional signal design and processing.The main contributions of this dissertation are as follows:1.In order to suppress the mainlobe velocity deceptive jamming,a cognitive design of pulse amplitude and phase method based on inexact alternating direction penalty method(IADPM)is proposed.By exploiting the Doppler information of the jamming and target through multi-delay matched processing,the weighted sum of the jamming energy and the target sidelobe energy in the specific Doppler band is minimized,which improves the target detection performance in the presence of velocity deceptive jamming.2.In order to suppress mainlobe smart jamming,a cognitive joint design of transmit waveform and receive filter method based on decoupled alternating direction penalty method(DCADPM)is proposed.By exploiting the parameters of the jamming signal through time-frequency analysis and deconvolution operation,the weighted sum of integrate sidelobe levels(ISLs)with respect to the receive filter and transmit waveform as well as the receive filter and jamming waveform is minimized,which can suppress many kinds of mainlobe smart jammings effectively.3.In order to suppress escort support jamming,a cognitive space-time signal separation method based on subarray blind signal processing is proposed.By exploiting the difference between the target and jamming signals in the space and time,the target echo and jamming signal are reconstructed by resorting to subarray multidimensional signal separation,which realizes mainlobe escort support suppressive and smart jamming suppression and target angle estimation.4.In order to suppress self-defense jamming,a cognitive polarimetric-time multichannel processing method based on polarimetric joint approximate diagonalization of eigen-matrices(P-JADE)is proposed.By exploiting the polarization diversity and the waveform irrelevant characteristic between the target and jamming signals,the target echo and jamming signal are separated effectively,which improves the capability of the mainlobe self-defense suppressive and smart jamming suppression.The effectiveness,applicable condition,and performance of the above methods have been verified by simulation experiments.The results show that the proposed methods can effectively resist mainlobe suppressive,deceptive and smart jammings,which can greatly improve the performance of radar system in the presence of mainlobe jamming.And the above methods can be applied to airborne,shipborne and other early warning/fire-control radar systems.