Research On Optimal Design Of Waveform Based On Phase Encoding

As the electromagnetic environment becomes more and more complex today,improving the radar's ability to detect weak and small targets has gradually become a research focus.The waveform optimization technology based on phase encoding not only performs well in sidelobe suppression,but also improves the performance of radar in complex environments such as multi-interference and clutter.Therefore,according to the design of different platforms and scenarios and the corresponding phase-encoded waveform optimization algorithm,on the one hand,it can improve the radar's ability to detect weak and small targets,and on the other hand,it can also provide corresponding theoretical support for the radar.This article uses Single-Input Single-Output(SISO)radar and Multiple-Input Multiple-Output(MIMO)radar as the platform.Research on related issues such as low sidelobe waveform design,mismatch filter weight design and orthogonal waveform design.The details are as follows:First,take the low sidelobe waveform of SISO radar as the research object,and study the signal model and its optimization design criteria.Aiming at the problem of designing low sidelobe waveforms based on Peak Sidelobe Level(PSL)as the criterion,this paper solves the problem by improving the simulated annealing algorithm.Firstly,the superiority of the update sequence is improved by fusing Simulated Annealing(SA)and chaotic optimization algorithms.Then the Doppler-type annealing curve is introduced to improve the optimal solution memory function of the algorithm.Through the comparison of experiments under the same conditions,the effectiveness of the improved chaotic simulated annealing algorithm in the waveform optimization design is confirmed.Secondly,in terms of mismatch filter design,this paper uses Integral sidelobe Level(ISL)and PSL as the criteria,and uses Mismatch filter loss(MMFL)as the constraint to create a multi-objective optimization function.Improved whale optimization algorithm based on Logistic mapping.It is verified by simulation that the designed mismatch filter filter has better performance and faster calculation efficiency than the classic algorithm.Thirdly,the problem of high relative sidelobes of the existing MIMO radar quadrature phase coded signal is addressed.This paper proposes a dynamic rotation angle update formula to improve the traditional Quantum Genetic Algorithm(QGA),and uses this algorithm to design the MIMO radar orthogonal signal waveform.Through theoretical analysis and simulation,the method can make the waveform have better auto-correlation and crosscorrelation characteristics.Finally,because the performance of transmitting multi-phase perfect complementary pairs with ideal correlation functions in a MIMO radar system is better than a single sequence.Therefore,this paper studies the application of Complete Complementary Sequence(CCS)in MIMO radar.On this basis,this paper introduces a crossover operator to extend the known complete complementary sequence.Through theoretical analysis and simulation,it is concluded that the new type of CCS has the properties of auto-correlation sidelobes and crosscorrelation all zero,and has a good application prospect in MIMO radar.