Research On Waveforms Design Technology Of Mainlobe Jamming Suppression For Airborne Cognitive Radar

Due to the lack of the adaptability of transmitting,receiving and processing,the traditional airborne radar will drop sharply when dealing with a wide variety of main lobe active interference.Cognitive radar is an advanced system radar with a closed-loop working mode and a variety of adaptive functions.It conforms to the development trend of radar intelligence,provides solutions for the above problems,and also points out the direction of development about airborne cognitive radar.Anti-main lobe active jamming technology is an important research direction of airborne cognitive radar.From the aspect of transmitting waveform design,combined with the environmental information perceived by cognitive technology,the complex parameter modulation within the pulse or between the pulses can be performed on the transmitted waveform,which can enhance the discrimination between the target and the interference,and fundamentally ensure the anti-interference ability of the airborne radar.Therefore,this thesis focuses on the suppression of airborne radar deception jamming and smart jamming,and studies the waveform design technology of airborne cognitive radar anti-main lobe jamming.The main work is as follows:1.The mechanism and characteristics of deception jamming and smart jamming under the background of airborne cognitive radar are analyzed,and the jamming echo signal model is established.An airborne cognitive radar waveform design system model for anti-active jamming with closed-loop workflow is established.The design criteria for anti-active interference waveforms based on minimizing WPSL and minimizing WISL are proposed.2.Aiming at the waveform design problem of airborne cognitive radar anti-rangespeed joint deception jamming,the transmit and echo signal models of radar under antirange-speed joint deception jamming are established.The suppression principle of distance-velocity joint deception jamming is analyzed from the perspective of waveform design,and a constant modulus constrained optimization problem based on the principle of minimizing WPSL is established.A pulse-to-pulse agile parameters waveform design technique based on BSUM-PSL algorithm is proposed.3.Aiming at the waveform design problem of anti-intermittent sampling dexterity interference of airborne cognitive radar,the transmit and echo signal models of radar under anti-intermittent sampling interference are established.The suppression principle of intermittent sampling interference is analyzed from the perspective of waveform design,and a constant modulus multi-constraint optimization problem based on the criterion of minimizing the weighted sum of "the WISL of the transmit waveform and the receive filter" and "the WISL of the interference signal and the receive filter" is constructed.A joint design technique of transmit waveform and receive filter based on WISL-ADPM algorithm is proposed.The computational complexity and convergence of the two anti-jamming waveform design algorithms are theoretically analyzed,and the algorithm performance and antijamming effectiveness are verified by simulation.The results show that the above algorithm has efficient convergence and can effectively help the airborne cognitive radar to suppress deception and smart main lobe jamming.